1ea272257SMauro Carvalho Chehab================ 2ea272257SMauro Carvalho ChehabEvent Histograms 3ea272257SMauro Carvalho Chehab================ 4ea272257SMauro Carvalho Chehab 5ea272257SMauro Carvalho ChehabDocumentation written by Tom Zanussi 6ea272257SMauro Carvalho Chehab 7ea272257SMauro Carvalho Chehab1. Introduction 8ea272257SMauro Carvalho Chehab=============== 9ea272257SMauro Carvalho Chehab 10ea272257SMauro Carvalho Chehab Histogram triggers are special event triggers that can be used to 11ea272257SMauro Carvalho Chehab aggregate trace event data into histograms. For information on 12ea272257SMauro Carvalho Chehab trace events and event triggers, see Documentation/trace/events.rst. 13ea272257SMauro Carvalho Chehab 14ea272257SMauro Carvalho Chehab 15ea272257SMauro Carvalho Chehab2. Histogram Trigger Command 16ea272257SMauro Carvalho Chehab============================ 17ea272257SMauro Carvalho Chehab 18ea272257SMauro Carvalho Chehab A histogram trigger command is an event trigger command that 19ea272257SMauro Carvalho Chehab aggregates event hits into a hash table keyed on one or more trace 20ea272257SMauro Carvalho Chehab event format fields (or stacktrace) and a set of running totals 21ea272257SMauro Carvalho Chehab derived from one or more trace event format fields and/or event 22ea272257SMauro Carvalho Chehab counts (hitcount). 23ea272257SMauro Carvalho Chehab 24ea272257SMauro Carvalho Chehab The format of a hist trigger is as follows:: 25ea272257SMauro Carvalho Chehab 26ea272257SMauro Carvalho Chehab hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>] 27ea272257SMauro Carvalho Chehab [:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue] 288c2b9979SMasami Hiramatsu (Google) [:clear][:name=histname1][:nohitcount][:<handler>.<action>] [if <filter>] 29ea272257SMauro Carvalho Chehab 30ea272257SMauro Carvalho Chehab When a matching event is hit, an entry is added to a hash table 31ea272257SMauro Carvalho Chehab using the key(s) and value(s) named. Keys and values correspond to 32ea272257SMauro Carvalho Chehab fields in the event's format description. Values must correspond to 33ea272257SMauro Carvalho Chehab numeric fields - on an event hit, the value(s) will be added to a 34ea272257SMauro Carvalho Chehab sum kept for that field. The special string 'hitcount' can be used 35ea272257SMauro Carvalho Chehab in place of an explicit value field - this is simply a count of 36ea272257SMauro Carvalho Chehab event hits. If 'values' isn't specified, an implicit 'hitcount' 37ea272257SMauro Carvalho Chehab value will be automatically created and used as the only value. 38*4b512860SSteven Rostedt (Google) Keys can be any field, or the special string 'common_stacktrace', which 39ea272257SMauro Carvalho Chehab will use the event's kernel stacktrace as the key. The keywords 40ea272257SMauro Carvalho Chehab 'keys' or 'key' can be used to specify keys, and the keywords 41ea272257SMauro Carvalho Chehab 'values', 'vals', or 'val' can be used to specify values. Compound 42a635beeaSZheng Yejian keys consisting of up to three fields can be specified by the 'keys' 43ea272257SMauro Carvalho Chehab keyword. Hashing a compound key produces a unique entry in the 44ea272257SMauro Carvalho Chehab table for each unique combination of component keys, and can be 45ea272257SMauro Carvalho Chehab useful for providing more fine-grained summaries of event data. 46ea272257SMauro Carvalho Chehab Additionally, sort keys consisting of up to two fields can be 47ea272257SMauro Carvalho Chehab specified by the 'sort' keyword. If more than one field is 48ea272257SMauro Carvalho Chehab specified, the result will be a 'sort within a sort': the first key 49ea272257SMauro Carvalho Chehab is taken to be the primary sort key and the second the secondary 50ea272257SMauro Carvalho Chehab key. If a hist trigger is given a name using the 'name' parameter, 51ea272257SMauro Carvalho Chehab its histogram data will be shared with other triggers of the same 52ea272257SMauro Carvalho Chehab name, and trigger hits will update this common data. Only triggers 53ea272257SMauro Carvalho Chehab with 'compatible' fields can be combined in this way; triggers are 54ea272257SMauro Carvalho Chehab 'compatible' if the fields named in the trigger share the same 55ea272257SMauro Carvalho Chehab number and type of fields and those fields also have the same names. 56ea272257SMauro Carvalho Chehab Note that any two events always share the compatible 'hitcount' and 57*4b512860SSteven Rostedt (Google) 'common_stacktrace' fields and can therefore be combined using those 58ea272257SMauro Carvalho Chehab fields, however pointless that may be. 59ea272257SMauro Carvalho Chehab 60ea272257SMauro Carvalho Chehab 'hist' triggers add a 'hist' file to each event's subdirectory. 61ea272257SMauro Carvalho Chehab Reading the 'hist' file for the event will dump the hash table in 62ea272257SMauro Carvalho Chehab its entirety to stdout. If there are multiple hist triggers 63ea272257SMauro Carvalho Chehab attached to an event, there will be a table for each trigger in the 64ea272257SMauro Carvalho Chehab output. The table displayed for a named trigger will be the same as 65ea272257SMauro Carvalho Chehab any other instance having the same name. Each printed hash table 66ea272257SMauro Carvalho Chehab entry is a simple list of the keys and values comprising the entry; 67ea272257SMauro Carvalho Chehab keys are printed first and are delineated by curly braces, and are 68ea272257SMauro Carvalho Chehab followed by the set of value fields for the entry. By default, 69ea272257SMauro Carvalho Chehab numeric fields are displayed as base-10 integers. This can be 70ea272257SMauro Carvalho Chehab modified by appending any of the following modifiers to the field 71ea272257SMauro Carvalho Chehab name: 72ea272257SMauro Carvalho Chehab 734420f5b1SSteven Rostedt (VMware) ============= ================================================= 74ea272257SMauro Carvalho Chehab .hex display a number as a hex value 75ea272257SMauro Carvalho Chehab .sym display an address as a symbol 76ea272257SMauro Carvalho Chehab .sym-offset display an address as a symbol and offset 77ea272257SMauro Carvalho Chehab .syscall display a syscall id as a system call name 78ea272257SMauro Carvalho Chehab .execname display a common_pid as a program name 79ea272257SMauro Carvalho Chehab .log2 display log2 value rather than raw number 8037036435SSteven Rostedt (VMware) .buckets=size display grouping of values rather than raw number 81ea272257SMauro Carvalho Chehab .usecs display a common_timestamp in microseconds 828c2b9979SMasami Hiramatsu (Google) .percent display a number of percentage value 838c2b9979SMasami Hiramatsu (Google) .graph display a bar-graph of a value 8488238513SSteven Rostedt (Google) .stacktrace display as a stacktrace (must by a long[] type) 854420f5b1SSteven Rostedt (VMware) ============= ================================================= 86ea272257SMauro Carvalho Chehab 87ea272257SMauro Carvalho Chehab Note that in general the semantics of a given field aren't 88ea272257SMauro Carvalho Chehab interpreted when applying a modifier to it, but there are some 89ea272257SMauro Carvalho Chehab restrictions to be aware of in this regard: 90ea272257SMauro Carvalho Chehab 91ea272257SMauro Carvalho Chehab - only the 'hex' modifier can be used for values (because values 92ea272257SMauro Carvalho Chehab are essentially sums, and the other modifiers don't make sense 93ea272257SMauro Carvalho Chehab in that context). 94ea272257SMauro Carvalho Chehab - the 'execname' modifier can only be used on a 'common_pid'. The 95ea272257SMauro Carvalho Chehab reason for this is that the execname is simply the 'comm' value 96ea272257SMauro Carvalho Chehab saved for the 'current' process when an event was triggered, 97ea272257SMauro Carvalho Chehab which is the same as the common_pid value saved by the event 98ea272257SMauro Carvalho Chehab tracing code. Trying to apply that comm value to other pid 99ea272257SMauro Carvalho Chehab values wouldn't be correct, and typically events that care save 100ea272257SMauro Carvalho Chehab pid-specific comm fields in the event itself. 101ea272257SMauro Carvalho Chehab 102ea272257SMauro Carvalho Chehab A typical usage scenario would be the following to enable a hist 103ea272257SMauro Carvalho Chehab trigger, read its current contents, and then turn it off:: 104ea272257SMauro Carvalho Chehab 105ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len' > \ 1062abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_rx/trigger 107ea272257SMauro Carvalho Chehab 1082abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_rx/hist 109ea272257SMauro Carvalho Chehab 110ea272257SMauro Carvalho Chehab # echo '!hist:keys=skbaddr.hex:vals=len' > \ 1112abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_rx/trigger 112ea272257SMauro Carvalho Chehab 113ea272257SMauro Carvalho Chehab The trigger file itself can be read to show the details of the 114ea272257SMauro Carvalho Chehab currently attached hist trigger. This information is also displayed 115ea272257SMauro Carvalho Chehab at the top of the 'hist' file when read. 116ea272257SMauro Carvalho Chehab 117ea272257SMauro Carvalho Chehab By default, the size of the hash table is 2048 entries. The 'size' 118ea272257SMauro Carvalho Chehab parameter can be used to specify more or fewer than that. The units 119ea272257SMauro Carvalho Chehab are in terms of hashtable entries - if a run uses more entries than 120ea272257SMauro Carvalho Chehab specified, the results will show the number of 'drops', the number 121ea272257SMauro Carvalho Chehab of hits that were ignored. The size should be a power of 2 between 122ea272257SMauro Carvalho Chehab 128 and 131072 (any non- power-of-2 number specified will be rounded 123ea272257SMauro Carvalho Chehab up). 124ea272257SMauro Carvalho Chehab 125ea272257SMauro Carvalho Chehab The 'sort' parameter can be used to specify a value field to sort 126ea272257SMauro Carvalho Chehab on. The default if unspecified is 'hitcount' and the default sort 127ea272257SMauro Carvalho Chehab order is 'ascending'. To sort in the opposite direction, append 128ea272257SMauro Carvalho Chehab .descending' to the sort key. 129ea272257SMauro Carvalho Chehab 130ea272257SMauro Carvalho Chehab The 'pause' parameter can be used to pause an existing hist trigger 131ea272257SMauro Carvalho Chehab or to start a hist trigger but not log any events until told to do 132ea272257SMauro Carvalho Chehab so. 'continue' or 'cont' can be used to start or restart a paused 133ea272257SMauro Carvalho Chehab hist trigger. 134ea272257SMauro Carvalho Chehab 135ea272257SMauro Carvalho Chehab The 'clear' parameter will clear the contents of a running hist 136ea272257SMauro Carvalho Chehab trigger and leave its current paused/active state. 137ea272257SMauro Carvalho Chehab 138ea272257SMauro Carvalho Chehab Note that the 'pause', 'cont', and 'clear' parameters should be 139ea272257SMauro Carvalho Chehab applied using 'append' shell operator ('>>') if applied to an 140ea272257SMauro Carvalho Chehab existing trigger, rather than via the '>' operator, which will cause 141ea272257SMauro Carvalho Chehab the trigger to be removed through truncation. 142ea272257SMauro Carvalho Chehab 1438c2b9979SMasami Hiramatsu (Google) The 'nohitcount' (or NOHC) parameter will suppress display of 1448c2b9979SMasami Hiramatsu (Google) raw hitcount in the histogram. This option requires at least one 1458c2b9979SMasami Hiramatsu (Google) value field which is not a 'raw hitcount'. For example, 1468c2b9979SMasami Hiramatsu (Google) 'hist:...:vals=hitcount:nohitcount' is rejected, but 1478c2b9979SMasami Hiramatsu (Google) 'hist:...:vals=hitcount.percent:nohitcount' is OK. 1488c2b9979SMasami Hiramatsu (Google) 149ea272257SMauro Carvalho Chehab- enable_hist/disable_hist 150ea272257SMauro Carvalho Chehab 151ea272257SMauro Carvalho Chehab The enable_hist and disable_hist triggers can be used to have one 152ea272257SMauro Carvalho Chehab event conditionally start and stop another event's already-attached 153ea272257SMauro Carvalho Chehab hist trigger. Any number of enable_hist and disable_hist triggers 154ea272257SMauro Carvalho Chehab can be attached to a given event, allowing that event to kick off 155ea272257SMauro Carvalho Chehab and stop aggregations on a host of other events. 156ea272257SMauro Carvalho Chehab 157ea272257SMauro Carvalho Chehab The format is very similar to the enable/disable_event triggers:: 158ea272257SMauro Carvalho Chehab 159ea272257SMauro Carvalho Chehab enable_hist:<system>:<event>[:count] 160ea272257SMauro Carvalho Chehab disable_hist:<system>:<event>[:count] 161ea272257SMauro Carvalho Chehab 162ea272257SMauro Carvalho Chehab Instead of enabling or disabling the tracing of the target event 163ea272257SMauro Carvalho Chehab into the trace buffer as the enable/disable_event triggers do, the 164ea272257SMauro Carvalho Chehab enable/disable_hist triggers enable or disable the aggregation of 165ea272257SMauro Carvalho Chehab the target event into a hash table. 166ea272257SMauro Carvalho Chehab 167ea272257SMauro Carvalho Chehab A typical usage scenario for the enable_hist/disable_hist triggers 168ea272257SMauro Carvalho Chehab would be to first set up a paused hist trigger on some event, 169ea272257SMauro Carvalho Chehab followed by an enable_hist/disable_hist pair that turns the hist 170ea272257SMauro Carvalho Chehab aggregation on and off when conditions of interest are hit:: 171ea272257SMauro Carvalho Chehab 172ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \ 1732abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 174ea272257SMauro Carvalho Chehab 175ea272257SMauro Carvalho Chehab # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ 1762abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exec/trigger 177ea272257SMauro Carvalho Chehab 178ea272257SMauro Carvalho Chehab # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ 1792abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exit/trigger 180ea272257SMauro Carvalho Chehab 181ea272257SMauro Carvalho Chehab The above sets up an initially paused hist trigger which is unpaused 182ea272257SMauro Carvalho Chehab and starts aggregating events when a given program is executed, and 183ea272257SMauro Carvalho Chehab which stops aggregating when the process exits and the hist trigger 184ea272257SMauro Carvalho Chehab is paused again. 185ea272257SMauro Carvalho Chehab 186ea272257SMauro Carvalho Chehab The examples below provide a more concrete illustration of the 187ea272257SMauro Carvalho Chehab concepts and typical usage patterns discussed above. 188ea272257SMauro Carvalho Chehab 189ea272257SMauro Carvalho Chehab'special' event fields 190ea272257SMauro Carvalho Chehab------------------------ 191ea272257SMauro Carvalho Chehab 192ea272257SMauro Carvalho Chehab There are a number of 'special event fields' available for use as 193ea272257SMauro Carvalho Chehab keys or values in a hist trigger. These look like and behave as if 194ea272257SMauro Carvalho Chehab they were actual event fields, but aren't really part of the event's 195ea272257SMauro Carvalho Chehab field definition or format file. They are however available for any 196ea272257SMauro Carvalho Chehab event, and can be used anywhere an actual event field could be. 197ea272257SMauro Carvalho Chehab They are: 198ea272257SMauro Carvalho Chehab 199ea272257SMauro Carvalho Chehab ====================== ==== ======================================= 200ea272257SMauro Carvalho Chehab common_timestamp u64 timestamp (from ring buffer) associated 201ea272257SMauro Carvalho Chehab with the event, in nanoseconds. May be 202ea272257SMauro Carvalho Chehab modified by .usecs to have timestamps 203ea272257SMauro Carvalho Chehab interpreted as microseconds. 2041e3bac71SSteven Rostedt (VMware) common_cpu int the cpu on which the event occurred. 205ea272257SMauro Carvalho Chehab ====================== ==== ======================================= 206ea272257SMauro Carvalho Chehab 207ea272257SMauro Carvalho ChehabExtended error information 208ea272257SMauro Carvalho Chehab-------------------------- 209ea272257SMauro Carvalho Chehab 210ea272257SMauro Carvalho Chehab For some error conditions encountered when invoking a hist trigger 211ea272257SMauro Carvalho Chehab command, extended error information is available via the 21226a94491STom Zanussi tracing/error_log file. See Error Conditions in 21326a94491STom Zanussi :file:`Documentation/trace/ftrace.rst` for details. 214ea272257SMauro Carvalho Chehab 215ea272257SMauro Carvalho Chehab6.2 'hist' trigger examples 216ea272257SMauro Carvalho Chehab--------------------------- 217ea272257SMauro Carvalho Chehab 218ea272257SMauro Carvalho Chehab The first set of examples creates aggregations using the kmalloc 219ea272257SMauro Carvalho Chehab event. The fields that can be used for the hist trigger are listed 220ea272257SMauro Carvalho Chehab in the kmalloc event's format file:: 221ea272257SMauro Carvalho Chehab 2222abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/format 223ea272257SMauro Carvalho Chehab name: kmalloc 224ea272257SMauro Carvalho Chehab ID: 374 225ea272257SMauro Carvalho Chehab format: 226ea272257SMauro Carvalho Chehab field:unsigned short common_type; offset:0; size:2; signed:0; 227ea272257SMauro Carvalho Chehab field:unsigned char common_flags; offset:2; size:1; signed:0; 228ea272257SMauro Carvalho Chehab field:unsigned char common_preempt_count; offset:3; size:1; signed:0; 229ea272257SMauro Carvalho Chehab field:int common_pid; offset:4; size:4; signed:1; 230ea272257SMauro Carvalho Chehab 231ea272257SMauro Carvalho Chehab field:unsigned long call_site; offset:8; size:8; signed:0; 232ea272257SMauro Carvalho Chehab field:const void * ptr; offset:16; size:8; signed:0; 233ea272257SMauro Carvalho Chehab field:size_t bytes_req; offset:24; size:8; signed:0; 234ea272257SMauro Carvalho Chehab field:size_t bytes_alloc; offset:32; size:8; signed:0; 235ea272257SMauro Carvalho Chehab field:gfp_t gfp_flags; offset:40; size:4; signed:0; 236ea272257SMauro Carvalho Chehab 237ea272257SMauro Carvalho Chehab We'll start by creating a hist trigger that generates a simple table 238ea272257SMauro Carvalho Chehab that lists the total number of bytes requested for each function in 239ea272257SMauro Carvalho Chehab the kernel that made one or more calls to kmalloc:: 240ea272257SMauro Carvalho Chehab 24137036435SSteven Rostedt (VMware) # echo 'hist:key=call_site:val=bytes_req.buckets=32' > \ 2422abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 243ea272257SMauro Carvalho Chehab 244ea272257SMauro Carvalho Chehab This tells the tracing system to create a 'hist' trigger using the 245ea272257SMauro Carvalho Chehab call_site field of the kmalloc event as the key for the table, which 246ea272257SMauro Carvalho Chehab just means that each unique call_site address will have an entry 247ea272257SMauro Carvalho Chehab created for it in the table. The 'val=bytes_req' parameter tells 248ea272257SMauro Carvalho Chehab the hist trigger that for each unique entry (call_site) in the 249ea272257SMauro Carvalho Chehab table, it should keep a running total of the number of bytes 250ea272257SMauro Carvalho Chehab requested by that call_site. 251ea272257SMauro Carvalho Chehab 252ea272257SMauro Carvalho Chehab We'll let it run for awhile and then dump the contents of the 'hist' 253ea272257SMauro Carvalho Chehab file in the kmalloc event's subdirectory (for readability, a number 254ea272257SMauro Carvalho Chehab of entries have been omitted):: 255ea272257SMauro Carvalho Chehab 2562abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 257ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] 258ea272257SMauro Carvalho Chehab 259ea272257SMauro Carvalho Chehab { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176 260ea272257SMauro Carvalho Chehab { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024 261ea272257SMauro Carvalho Chehab { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384 262ea272257SMauro Carvalho Chehab { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24 263ea272257SMauro Carvalho Chehab { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8 264ea272257SMauro Carvalho Chehab { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152 265ea272257SMauro Carvalho Chehab { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144 266ea272257SMauro Carvalho Chehab { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144 267ea272257SMauro Carvalho Chehab { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560 268ea272257SMauro Carvalho Chehab { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736 269ea272257SMauro Carvalho Chehab . 270ea272257SMauro Carvalho Chehab . 271ea272257SMauro Carvalho Chehab . 272ea272257SMauro Carvalho Chehab { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576 273ea272257SMauro Carvalho Chehab { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336 274ea272257SMauro Carvalho Chehab { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504 275ea272257SMauro Carvalho Chehab { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584 276ea272257SMauro Carvalho Chehab { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448 277ea272257SMauro Carvalho Chehab { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720 278ea272257SMauro Carvalho Chehab { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088 279ea272257SMauro Carvalho Chehab { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920 280ea272257SMauro Carvalho Chehab { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716 281ea272257SMauro Carvalho Chehab { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712 282ea272257SMauro Carvalho Chehab { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160 283ea272257SMauro Carvalho Chehab { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520 284ea272257SMauro Carvalho Chehab 285ea272257SMauro Carvalho Chehab Totals: 286ea272257SMauro Carvalho Chehab Hits: 4610 287ea272257SMauro Carvalho Chehab Entries: 45 288ea272257SMauro Carvalho Chehab Dropped: 0 289ea272257SMauro Carvalho Chehab 290ea272257SMauro Carvalho Chehab The output displays a line for each entry, beginning with the key 291ea272257SMauro Carvalho Chehab specified in the trigger, followed by the value(s) also specified in 292ea272257SMauro Carvalho Chehab the trigger. At the beginning of the output is a line that displays 293ea272257SMauro Carvalho Chehab the trigger info, which can also be displayed by reading the 294ea272257SMauro Carvalho Chehab 'trigger' file:: 295ea272257SMauro Carvalho Chehab 2962abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/trigger 297ea272257SMauro Carvalho Chehab hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] 298ea272257SMauro Carvalho Chehab 299ea272257SMauro Carvalho Chehab At the end of the output are a few lines that display the overall 300ea272257SMauro Carvalho Chehab totals for the run. The 'Hits' field shows the total number of 301ea272257SMauro Carvalho Chehab times the event trigger was hit, the 'Entries' field shows the total 302ea272257SMauro Carvalho Chehab number of used entries in the hash table, and the 'Dropped' field 303ea272257SMauro Carvalho Chehab shows the number of hits that were dropped because the number of 304ea272257SMauro Carvalho Chehab used entries for the run exceeded the maximum number of entries 305ea272257SMauro Carvalho Chehab allowed for the table (normally 0, but if not a hint that you may 306ea272257SMauro Carvalho Chehab want to increase the size of the table using the 'size' parameter). 307ea272257SMauro Carvalho Chehab 308ea272257SMauro Carvalho Chehab Notice in the above output that there's an extra field, 'hitcount', 309ea272257SMauro Carvalho Chehab which wasn't specified in the trigger. Also notice that in the 310ea272257SMauro Carvalho Chehab trigger info output, there's a parameter, 'sort=hitcount', which 311ea272257SMauro Carvalho Chehab wasn't specified in the trigger either. The reason for that is that 312ea272257SMauro Carvalho Chehab every trigger implicitly keeps a count of the total number of hits 313ea272257SMauro Carvalho Chehab attributed to a given entry, called the 'hitcount'. That hitcount 314ea272257SMauro Carvalho Chehab information is explicitly displayed in the output, and in the 315ea272257SMauro Carvalho Chehab absence of a user-specified sort parameter, is used as the default 316ea272257SMauro Carvalho Chehab sort field. 317ea272257SMauro Carvalho Chehab 318ea272257SMauro Carvalho Chehab The value 'hitcount' can be used in place of an explicit value in 319ea272257SMauro Carvalho Chehab the 'values' parameter if you don't really need to have any 320ea272257SMauro Carvalho Chehab particular field summed and are mainly interested in hit 321ea272257SMauro Carvalho Chehab frequencies. 322ea272257SMauro Carvalho Chehab 323ea272257SMauro Carvalho Chehab To turn the hist trigger off, simply call up the trigger in the 324ea272257SMauro Carvalho Chehab command history and re-execute it with a '!' prepended:: 325ea272257SMauro Carvalho Chehab 326ea272257SMauro Carvalho Chehab # echo '!hist:key=call_site:val=bytes_req' > \ 3272abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 328ea272257SMauro Carvalho Chehab 329ea272257SMauro Carvalho Chehab Finally, notice that the call_site as displayed in the output above 330ea272257SMauro Carvalho Chehab isn't really very useful. It's an address, but normally addresses 331ea272257SMauro Carvalho Chehab are displayed in hex. To have a numeric field displayed as a hex 332ea272257SMauro Carvalho Chehab value, simply append '.hex' to the field name in the trigger:: 333ea272257SMauro Carvalho Chehab 334ea272257SMauro Carvalho Chehab # echo 'hist:key=call_site.hex:val=bytes_req' > \ 3352abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 336ea272257SMauro Carvalho Chehab 3372abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 338ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active] 339ea272257SMauro Carvalho Chehab 340ea272257SMauro Carvalho Chehab { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433 341ea272257SMauro Carvalho Chehab { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176 342ea272257SMauro Carvalho Chehab { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384 343ea272257SMauro Carvalho Chehab { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8 344ea272257SMauro Carvalho Chehab { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511 345ea272257SMauro Carvalho Chehab { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12 346ea272257SMauro Carvalho Chehab { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152 347ea272257SMauro Carvalho Chehab { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24 348ea272257SMauro Carvalho Chehab { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144 349ea272257SMauro Carvalho Chehab { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648 350ea272257SMauro Carvalho Chehab { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144 351ea272257SMauro Carvalho Chehab { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544 352ea272257SMauro Carvalho Chehab . 353ea272257SMauro Carvalho Chehab . 354ea272257SMauro Carvalho Chehab . 355ea272257SMauro Carvalho Chehab { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024 356ea272257SMauro Carvalho Chehab { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680 357ea272257SMauro Carvalho Chehab { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112 358ea272257SMauro Carvalho Chehab { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232 359ea272257SMauro Carvalho Chehab { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360 360ea272257SMauro Carvalho Chehab { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640 361ea272257SMauro Carvalho Chehab { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600 362ea272257SMauro Carvalho Chehab { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584 363ea272257SMauro Carvalho Chehab { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656 364ea272257SMauro Carvalho Chehab { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456 365ea272257SMauro Carvalho Chehab { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600 366ea272257SMauro Carvalho Chehab 367ea272257SMauro Carvalho Chehab Totals: 368ea272257SMauro Carvalho Chehab Hits: 4775 369ea272257SMauro Carvalho Chehab Entries: 46 370ea272257SMauro Carvalho Chehab Dropped: 0 371ea272257SMauro Carvalho Chehab 372ea272257SMauro Carvalho Chehab Even that's only marginally more useful - while hex values do look 373ea272257SMauro Carvalho Chehab more like addresses, what users are typically more interested in 374ea272257SMauro Carvalho Chehab when looking at text addresses are the corresponding symbols 375ea272257SMauro Carvalho Chehab instead. To have an address displayed as symbolic value instead, 376ea272257SMauro Carvalho Chehab simply append '.sym' or '.sym-offset' to the field name in the 377ea272257SMauro Carvalho Chehab trigger:: 378ea272257SMauro Carvalho Chehab 379ea272257SMauro Carvalho Chehab # echo 'hist:key=call_site.sym:val=bytes_req' > \ 3802abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 381ea272257SMauro Carvalho Chehab 3822abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 383ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active] 384ea272257SMauro Carvalho Chehab 385ea272257SMauro Carvalho Chehab { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024 386ea272257SMauro Carvalho Chehab { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 387ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 388ea272257SMauro Carvalho Chehab { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192 389ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 390ea272257SMauro Carvalho Chehab { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 391ea272257SMauro Carvalho Chehab { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 392ea272257SMauro Carvalho Chehab { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528 393ea272257SMauro Carvalho Chehab { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624 394ea272257SMauro Carvalho Chehab { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96 395ea272257SMauro Carvalho Chehab { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464 396ea272257SMauro Carvalho Chehab { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304 397ea272257SMauro Carvalho Chehab { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 398ea272257SMauro Carvalho Chehab { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424 399ea272257SMauro Carvalho Chehab . 400ea272257SMauro Carvalho Chehab . 401ea272257SMauro Carvalho Chehab . 402ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240 403ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280 404ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672 405ea272257SMauro Carvalho Chehab { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208 406ea272257SMauro Carvalho Chehab { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840 407ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312 408ea272257SMauro Carvalho Chehab { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152 409ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576 410ea272257SMauro Carvalho Chehab { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248 411ea272257SMauro Carvalho Chehab { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384 412ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584 413ea272257SMauro Carvalho Chehab { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176 414ea272257SMauro Carvalho Chehab { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265 415ea272257SMauro Carvalho Chehab 416ea272257SMauro Carvalho Chehab Totals: 417ea272257SMauro Carvalho Chehab Hits: 109928 418ea272257SMauro Carvalho Chehab Entries: 71 419ea272257SMauro Carvalho Chehab Dropped: 0 420ea272257SMauro Carvalho Chehab 421ea272257SMauro Carvalho Chehab Because the default sort key above is 'hitcount', the above shows a 422ea272257SMauro Carvalho Chehab the list of call_sites by increasing hitcount, so that at the bottom 423ea272257SMauro Carvalho Chehab we see the functions that made the most kmalloc calls during the 4247f77ebbfSAkhil Raj run. If instead we wanted to see the top kmalloc callers in 425ea272257SMauro Carvalho Chehab terms of the number of bytes requested rather than the number of 426ea272257SMauro Carvalho Chehab calls, and we wanted the top caller to appear at the top, we can use 427ea272257SMauro Carvalho Chehab the 'sort' parameter, along with the 'descending' modifier:: 428ea272257SMauro Carvalho Chehab 429ea272257SMauro Carvalho Chehab # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \ 4302abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 431ea272257SMauro Carvalho Chehab 4322abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 433ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] 434ea272257SMauro Carvalho Chehab 435ea272257SMauro Carvalho Chehab { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464 436ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176 437ea272257SMauro Carvalho Chehab { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135 438ea272257SMauro Carvalho Chehab { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128 439ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784 440ea272257SMauro Carvalho Chehab { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992 441ea272257SMauro Carvalho Chehab { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072 442ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824 443ea272257SMauro Carvalho Chehab { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704 444ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088 445ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536 446ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664 447ea272257SMauro Carvalho Chehab { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632 448ea272257SMauro Carvalho Chehab . 449ea272257SMauro Carvalho Chehab . 450ea272257SMauro Carvalho Chehab . 451ea272257SMauro Carvalho Chehab { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 452ea272257SMauro Carvalho Chehab { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 453ea272257SMauro Carvalho Chehab { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48 454ea272257SMauro Carvalho Chehab { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48 455ea272257SMauro Carvalho Chehab { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48 456ea272257SMauro Carvalho Chehab { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 457ea272257SMauro Carvalho Chehab { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16 458ea272257SMauro Carvalho Chehab { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 459ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 460ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 461ea272257SMauro Carvalho Chehab 462ea272257SMauro Carvalho Chehab Totals: 463ea272257SMauro Carvalho Chehab Hits: 32133 464ea272257SMauro Carvalho Chehab Entries: 81 465ea272257SMauro Carvalho Chehab Dropped: 0 466ea272257SMauro Carvalho Chehab 467ea272257SMauro Carvalho Chehab To display the offset and size information in addition to the symbol 468ea272257SMauro Carvalho Chehab name, just use 'sym-offset' instead:: 469ea272257SMauro Carvalho Chehab 470ea272257SMauro Carvalho Chehab # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \ 4712abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 472ea272257SMauro Carvalho Chehab 4732abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 474ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] 475ea272257SMauro Carvalho Chehab 476ea272257SMauro Carvalho Chehab { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720 477ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936 478ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936 479ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832 480ea272257SMauro Carvalho Chehab { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384 481ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040 482ea272257SMauro Carvalho Chehab { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072 483ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880 484ea272257SMauro Carvalho Chehab { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488 485ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696 486ea272257SMauro Carvalho Chehab { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640 487ea272257SMauro Carvalho Chehab { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456 488ea272257SMauro Carvalho Chehab . 489ea272257SMauro Carvalho Chehab . 490ea272257SMauro Carvalho Chehab . 491ea272257SMauro Carvalho Chehab { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128 492ea272257SMauro Carvalho Chehab { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96 493ea272257SMauro Carvalho Chehab { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96 494ea272257SMauro Carvalho Chehab { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84 495ea272257SMauro Carvalho Chehab { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8 496ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7 497ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7 498ea272257SMauro Carvalho Chehab 499ea272257SMauro Carvalho Chehab Totals: 500ea272257SMauro Carvalho Chehab Hits: 26098 501ea272257SMauro Carvalho Chehab Entries: 64 502ea272257SMauro Carvalho Chehab Dropped: 0 503ea272257SMauro Carvalho Chehab 504ea272257SMauro Carvalho Chehab We can also add multiple fields to the 'values' parameter. For 505ea272257SMauro Carvalho Chehab example, we might want to see the total number of bytes allocated 506ea272257SMauro Carvalho Chehab alongside bytes requested, and display the result sorted by bytes 507ea272257SMauro Carvalho Chehab allocated in a descending order:: 508ea272257SMauro Carvalho Chehab 509ea272257SMauro Carvalho Chehab # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \ 5102abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 511ea272257SMauro Carvalho Chehab 5122abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 513ea272257SMauro Carvalho Chehab # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active] 514ea272257SMauro Carvalho Chehab 515ea272257SMauro Carvalho Chehab { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016 516ea272257SMauro Carvalho Chehab { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224 517ea272257SMauro Carvalho Chehab { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568 518ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760 519ea272257SMauro Carvalho Chehab { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744 520ea272257SMauro Carvalho Chehab { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400 521ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496 522ea272257SMauro Carvalho Chehab { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304 523ea272257SMauro Carvalho Chehab { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640 524ea272257SMauro Carvalho Chehab { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760 525ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312 526ea272257SMauro Carvalho Chehab { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432 527ea272257SMauro Carvalho Chehab . 528ea272257SMauro Carvalho Chehab . 529ea272257SMauro Carvalho Chehab . 530ea272257SMauro Carvalho Chehab { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192 531ea272257SMauro Carvalho Chehab { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 532ea272257SMauro Carvalho Chehab { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 533ea272257SMauro Carvalho Chehab { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 534ea272257SMauro Carvalho Chehab { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 535ea272257SMauro Carvalho Chehab { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96 536ea272257SMauro Carvalho Chehab { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64 537ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 538ea272257SMauro Carvalho Chehab { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8 539ea272257SMauro Carvalho Chehab { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 540ea272257SMauro Carvalho Chehab 541ea272257SMauro Carvalho Chehab Totals: 542ea272257SMauro Carvalho Chehab Hits: 66598 543ea272257SMauro Carvalho Chehab Entries: 65 544ea272257SMauro Carvalho Chehab Dropped: 0 545ea272257SMauro Carvalho Chehab 546ea272257SMauro Carvalho Chehab Finally, to finish off our kmalloc example, instead of simply having 547ea272257SMauro Carvalho Chehab the hist trigger display symbolic call_sites, we can have the hist 548ea272257SMauro Carvalho Chehab trigger additionally display the complete set of kernel stack traces 549ea272257SMauro Carvalho Chehab that led to each call_site. To do that, we simply use the special 550*4b512860SSteven Rostedt (Google) value 'common_stacktrace' for the key parameter:: 551ea272257SMauro Carvalho Chehab 552*4b512860SSteven Rostedt (Google) # echo 'hist:keys=common_stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \ 5532abfcd29SRoss Zwisler /sys/kernel/tracing/events/kmem/kmalloc/trigger 554ea272257SMauro Carvalho Chehab 555ea272257SMauro Carvalho Chehab The above trigger will use the kernel stack trace in effect when an 556ea272257SMauro Carvalho Chehab event is triggered as the key for the hash table. This allows the 557ea272257SMauro Carvalho Chehab enumeration of every kernel callpath that led up to a particular 558ea272257SMauro Carvalho Chehab event, along with a running total of any of the event fields for 559ea272257SMauro Carvalho Chehab that event. Here we tally bytes requested and bytes allocated for 560ea272257SMauro Carvalho Chehab every callpath in the system that led up to a kmalloc (in this case 561ea272257SMauro Carvalho Chehab every callpath to a kmalloc for a kernel compile):: 562ea272257SMauro Carvalho Chehab 5632abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/kmem/kmalloc/hist 564*4b512860SSteven Rostedt (Google) # trigger info: hist:keys=common_stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active] 565ea272257SMauro Carvalho Chehab 566*4b512860SSteven Rostedt (Google) { common_stacktrace: 567ea272257SMauro Carvalho Chehab __kmalloc_track_caller+0x10b/0x1a0 568ea272257SMauro Carvalho Chehab kmemdup+0x20/0x50 569ea272257SMauro Carvalho Chehab hidraw_report_event+0x8a/0x120 [hid] 570ea272257SMauro Carvalho Chehab hid_report_raw_event+0x3ea/0x440 [hid] 571ea272257SMauro Carvalho Chehab hid_input_report+0x112/0x190 [hid] 572ea272257SMauro Carvalho Chehab hid_irq_in+0xc2/0x260 [usbhid] 573ea272257SMauro Carvalho Chehab __usb_hcd_giveback_urb+0x72/0x120 574ea272257SMauro Carvalho Chehab usb_giveback_urb_bh+0x9e/0xe0 575ea272257SMauro Carvalho Chehab tasklet_hi_action+0xf8/0x100 576ea272257SMauro Carvalho Chehab __do_softirq+0x114/0x2c0 577ea272257SMauro Carvalho Chehab irq_exit+0xa5/0xb0 578ea272257SMauro Carvalho Chehab do_IRQ+0x5a/0xf0 579ea272257SMauro Carvalho Chehab ret_from_intr+0x0/0x30 580ea272257SMauro Carvalho Chehab cpuidle_enter+0x17/0x20 581ea272257SMauro Carvalho Chehab cpu_startup_entry+0x315/0x3e0 582ea272257SMauro Carvalho Chehab rest_init+0x7c/0x80 583ea272257SMauro Carvalho Chehab } hitcount: 3 bytes_req: 21 bytes_alloc: 24 584*4b512860SSteven Rostedt (Google) { common_stacktrace: 585ea272257SMauro Carvalho Chehab __kmalloc_track_caller+0x10b/0x1a0 586ea272257SMauro Carvalho Chehab kmemdup+0x20/0x50 587ea272257SMauro Carvalho Chehab hidraw_report_event+0x8a/0x120 [hid] 588ea272257SMauro Carvalho Chehab hid_report_raw_event+0x3ea/0x440 [hid] 589ea272257SMauro Carvalho Chehab hid_input_report+0x112/0x190 [hid] 590ea272257SMauro Carvalho Chehab hid_irq_in+0xc2/0x260 [usbhid] 591ea272257SMauro Carvalho Chehab __usb_hcd_giveback_urb+0x72/0x120 592ea272257SMauro Carvalho Chehab usb_giveback_urb_bh+0x9e/0xe0 593ea272257SMauro Carvalho Chehab tasklet_hi_action+0xf8/0x100 594ea272257SMauro Carvalho Chehab __do_softirq+0x114/0x2c0 595ea272257SMauro Carvalho Chehab irq_exit+0xa5/0xb0 596ea272257SMauro Carvalho Chehab do_IRQ+0x5a/0xf0 597ea272257SMauro Carvalho Chehab ret_from_intr+0x0/0x30 598ea272257SMauro Carvalho Chehab } hitcount: 3 bytes_req: 21 bytes_alloc: 24 599*4b512860SSteven Rostedt (Google) { common_stacktrace: 600ea272257SMauro Carvalho Chehab kmem_cache_alloc_trace+0xeb/0x150 601ea272257SMauro Carvalho Chehab aa_alloc_task_context+0x27/0x40 602ea272257SMauro Carvalho Chehab apparmor_cred_prepare+0x1f/0x50 603ea272257SMauro Carvalho Chehab security_prepare_creds+0x16/0x20 604ea272257SMauro Carvalho Chehab prepare_creds+0xdf/0x1a0 605ea272257SMauro Carvalho Chehab SyS_capset+0xb5/0x200 606ea272257SMauro Carvalho Chehab system_call_fastpath+0x12/0x6a 607ea272257SMauro Carvalho Chehab } hitcount: 1 bytes_req: 32 bytes_alloc: 32 608ea272257SMauro Carvalho Chehab . 609ea272257SMauro Carvalho Chehab . 610ea272257SMauro Carvalho Chehab . 611*4b512860SSteven Rostedt (Google) { common_stacktrace: 612ea272257SMauro Carvalho Chehab __kmalloc+0x11b/0x1b0 613ea272257SMauro Carvalho Chehab i915_gem_execbuffer2+0x6c/0x2c0 [i915] 614ea272257SMauro Carvalho Chehab drm_ioctl+0x349/0x670 [drm] 615ea272257SMauro Carvalho Chehab do_vfs_ioctl+0x2f0/0x4f0 616ea272257SMauro Carvalho Chehab SyS_ioctl+0x81/0xa0 617ea272257SMauro Carvalho Chehab system_call_fastpath+0x12/0x6a 618ea272257SMauro Carvalho Chehab } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808 619*4b512860SSteven Rostedt (Google) { common_stacktrace: 620ea272257SMauro Carvalho Chehab __kmalloc+0x11b/0x1b0 621ea272257SMauro Carvalho Chehab load_elf_phdrs+0x76/0xa0 622ea272257SMauro Carvalho Chehab load_elf_binary+0x102/0x1650 623ea272257SMauro Carvalho Chehab search_binary_handler+0x97/0x1d0 624ea272257SMauro Carvalho Chehab do_execveat_common.isra.34+0x551/0x6e0 625ea272257SMauro Carvalho Chehab SyS_execve+0x3a/0x50 626ea272257SMauro Carvalho Chehab return_from_execve+0x0/0x23 627ea272257SMauro Carvalho Chehab } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048 628*4b512860SSteven Rostedt (Google) { common_stacktrace: 629ea272257SMauro Carvalho Chehab kmem_cache_alloc_trace+0xeb/0x150 630ea272257SMauro Carvalho Chehab apparmor_file_alloc_security+0x27/0x40 631ea272257SMauro Carvalho Chehab security_file_alloc+0x16/0x20 632ea272257SMauro Carvalho Chehab get_empty_filp+0x93/0x1c0 633ea272257SMauro Carvalho Chehab path_openat+0x31/0x5f0 634ea272257SMauro Carvalho Chehab do_filp_open+0x3a/0x90 635ea272257SMauro Carvalho Chehab do_sys_open+0x128/0x220 636ea272257SMauro Carvalho Chehab SyS_open+0x1e/0x20 637ea272257SMauro Carvalho Chehab system_call_fastpath+0x12/0x6a 638ea272257SMauro Carvalho Chehab } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376 639*4b512860SSteven Rostedt (Google) { common_stacktrace: 640ea272257SMauro Carvalho Chehab __kmalloc+0x11b/0x1b0 641ea272257SMauro Carvalho Chehab seq_buf_alloc+0x1b/0x50 642ea272257SMauro Carvalho Chehab seq_read+0x2cc/0x370 643ea272257SMauro Carvalho Chehab proc_reg_read+0x3d/0x80 644ea272257SMauro Carvalho Chehab __vfs_read+0x28/0xe0 645ea272257SMauro Carvalho Chehab vfs_read+0x86/0x140 646ea272257SMauro Carvalho Chehab SyS_read+0x46/0xb0 647ea272257SMauro Carvalho Chehab system_call_fastpath+0x12/0x6a 648ea272257SMauro Carvalho Chehab } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768 649ea272257SMauro Carvalho Chehab 650ea272257SMauro Carvalho Chehab Totals: 651ea272257SMauro Carvalho Chehab Hits: 6085872 652ea272257SMauro Carvalho Chehab Entries: 253 653ea272257SMauro Carvalho Chehab Dropped: 0 654ea272257SMauro Carvalho Chehab 655ea272257SMauro Carvalho Chehab If you key a hist trigger on common_pid, in order for example to 656ea272257SMauro Carvalho Chehab gather and display sorted totals for each process, you can use the 657ea272257SMauro Carvalho Chehab special .execname modifier to display the executable names for the 658ea272257SMauro Carvalho Chehab processes in the table rather than raw pids. The example below 659ea272257SMauro Carvalho Chehab keeps a per-process sum of total bytes read:: 660ea272257SMauro Carvalho Chehab 661ea272257SMauro Carvalho Chehab # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \ 6622abfcd29SRoss Zwisler /sys/kernel/tracing/events/syscalls/sys_enter_read/trigger 663ea272257SMauro Carvalho Chehab 6642abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/syscalls/sys_enter_read/hist 665ea272257SMauro Carvalho Chehab # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active] 666ea272257SMauro Carvalho Chehab 667ea272257SMauro Carvalho Chehab { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512 668ea272257SMauro Carvalho Chehab { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640 669ea272257SMauro Carvalho Chehab { common_pid: compiz [ 2889] } hitcount: 59 count: 254400 670ea272257SMauro Carvalho Chehab { common_pid: bash [ 8710] } hitcount: 3 count: 66369 671ea272257SMauro Carvalho Chehab { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739 672ea272257SMauro Carvalho Chehab { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648 673ea272257SMauro Carvalho Chehab { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216 674ea272257SMauro Carvalho Chehab { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396 675ea272257SMauro Carvalho Chehab { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264 676ea272257SMauro Carvalho Chehab { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424 677ea272257SMauro Carvalho Chehab { common_pid: gmain [ 1315] } hitcount: 18 count: 6336 678ea272257SMauro Carvalho Chehab . 679ea272257SMauro Carvalho Chehab . 680ea272257SMauro Carvalho Chehab . 681ea272257SMauro Carvalho Chehab { common_pid: postgres [ 1892] } hitcount: 2 count: 32 682ea272257SMauro Carvalho Chehab { common_pid: postgres [ 1891] } hitcount: 2 count: 32 683ea272257SMauro Carvalho Chehab { common_pid: gmain [ 8704] } hitcount: 2 count: 32 684ea272257SMauro Carvalho Chehab { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21 685ea272257SMauro Carvalho Chehab { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16 686ea272257SMauro Carvalho Chehab { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16 687ea272257SMauro Carvalho Chehab { common_pid: gdbus [ 2998] } hitcount: 1 count: 16 688ea272257SMauro Carvalho Chehab { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8 689ea272257SMauro Carvalho Chehab { common_pid: init [ 1] } hitcount: 2 count: 2 690ea272257SMauro Carvalho Chehab 691ea272257SMauro Carvalho Chehab Totals: 692ea272257SMauro Carvalho Chehab Hits: 2116 693ea272257SMauro Carvalho Chehab Entries: 51 694ea272257SMauro Carvalho Chehab Dropped: 0 695ea272257SMauro Carvalho Chehab 696ea272257SMauro Carvalho Chehab Similarly, if you key a hist trigger on syscall id, for example to 697ea272257SMauro Carvalho Chehab gather and display a list of systemwide syscall hits, you can use 698ea272257SMauro Carvalho Chehab the special .syscall modifier to display the syscall names rather 699ea272257SMauro Carvalho Chehab than raw ids. The example below keeps a running total of syscall 700ea272257SMauro Carvalho Chehab counts for the system during the run:: 701ea272257SMauro Carvalho Chehab 702ea272257SMauro Carvalho Chehab # echo 'hist:key=id.syscall:val=hitcount' > \ 7032abfcd29SRoss Zwisler /sys/kernel/tracing/events/raw_syscalls/sys_enter/trigger 704ea272257SMauro Carvalho Chehab 7052abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/raw_syscalls/sys_enter/hist 706ea272257SMauro Carvalho Chehab # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active] 707ea272257SMauro Carvalho Chehab 708ea272257SMauro Carvalho Chehab { id: sys_fsync [ 74] } hitcount: 1 709ea272257SMauro Carvalho Chehab { id: sys_newuname [ 63] } hitcount: 1 710ea272257SMauro Carvalho Chehab { id: sys_prctl [157] } hitcount: 1 711ea272257SMauro Carvalho Chehab { id: sys_statfs [137] } hitcount: 1 712ea272257SMauro Carvalho Chehab { id: sys_symlink [ 88] } hitcount: 1 713ea272257SMauro Carvalho Chehab { id: sys_sendmmsg [307] } hitcount: 1 714ea272257SMauro Carvalho Chehab { id: sys_semctl [ 66] } hitcount: 1 715ea272257SMauro Carvalho Chehab { id: sys_readlink [ 89] } hitcount: 3 716ea272257SMauro Carvalho Chehab { id: sys_bind [ 49] } hitcount: 3 717ea272257SMauro Carvalho Chehab { id: sys_getsockname [ 51] } hitcount: 3 718ea272257SMauro Carvalho Chehab { id: sys_unlink [ 87] } hitcount: 3 719ea272257SMauro Carvalho Chehab { id: sys_rename [ 82] } hitcount: 4 720ea272257SMauro Carvalho Chehab { id: unknown_syscall [ 58] } hitcount: 4 721ea272257SMauro Carvalho Chehab { id: sys_connect [ 42] } hitcount: 4 722ea272257SMauro Carvalho Chehab { id: sys_getpid [ 39] } hitcount: 4 723ea272257SMauro Carvalho Chehab . 724ea272257SMauro Carvalho Chehab . 725ea272257SMauro Carvalho Chehab . 726ea272257SMauro Carvalho Chehab { id: sys_rt_sigprocmask [ 14] } hitcount: 952 727ea272257SMauro Carvalho Chehab { id: sys_futex [202] } hitcount: 1534 728ea272257SMauro Carvalho Chehab { id: sys_write [ 1] } hitcount: 2689 729ea272257SMauro Carvalho Chehab { id: sys_setitimer [ 38] } hitcount: 2797 730ea272257SMauro Carvalho Chehab { id: sys_read [ 0] } hitcount: 3202 731ea272257SMauro Carvalho Chehab { id: sys_select [ 23] } hitcount: 3773 732ea272257SMauro Carvalho Chehab { id: sys_writev [ 20] } hitcount: 4531 733ea272257SMauro Carvalho Chehab { id: sys_poll [ 7] } hitcount: 8314 734ea272257SMauro Carvalho Chehab { id: sys_recvmsg [ 47] } hitcount: 13738 735ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16] } hitcount: 21843 736ea272257SMauro Carvalho Chehab 737ea272257SMauro Carvalho Chehab Totals: 738ea272257SMauro Carvalho Chehab Hits: 67612 739ea272257SMauro Carvalho Chehab Entries: 72 740ea272257SMauro Carvalho Chehab Dropped: 0 741ea272257SMauro Carvalho Chehab 742ea272257SMauro Carvalho Chehab The syscall counts above provide a rough overall picture of system 743ea272257SMauro Carvalho Chehab call activity on the system; we can see for example that the most 744ea272257SMauro Carvalho Chehab popular system call on this system was the 'sys_ioctl' system call. 745ea272257SMauro Carvalho Chehab 746ea272257SMauro Carvalho Chehab We can use 'compound' keys to refine that number and provide some 747ea272257SMauro Carvalho Chehab further insight as to which processes exactly contribute to the 748ea272257SMauro Carvalho Chehab overall ioctl count. 749ea272257SMauro Carvalho Chehab 750ea272257SMauro Carvalho Chehab The command below keeps a hitcount for every unique combination of 751ea272257SMauro Carvalho Chehab system call id and pid - the end result is essentially a table 752ea272257SMauro Carvalho Chehab that keeps a per-pid sum of system call hits. The results are 753ea272257SMauro Carvalho Chehab sorted using the system call id as the primary key, and the 754ea272257SMauro Carvalho Chehab hitcount sum as the secondary key:: 755ea272257SMauro Carvalho Chehab 756ea272257SMauro Carvalho Chehab # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \ 7572abfcd29SRoss Zwisler /sys/kernel/tracing/events/raw_syscalls/sys_enter/trigger 758ea272257SMauro Carvalho Chehab 7592abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/raw_syscalls/sys_enter/hist 760ea272257SMauro Carvalho Chehab # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active] 761ea272257SMauro Carvalho Chehab 762ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1 763ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1 764ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1 765ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1 766ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2 767ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2 768ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2 769ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2 770ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2 771ea272257SMauro Carvalho Chehab { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2 772ea272257SMauro Carvalho Chehab . 773ea272257SMauro Carvalho Chehab . 774ea272257SMauro Carvalho Chehab . 775ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1 776ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12 777ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16 778ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808 779ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580 780ea272257SMauro Carvalho Chehab . 781ea272257SMauro Carvalho Chehab . 782ea272257SMauro Carvalho Chehab . 783ea272257SMauro Carvalho Chehab { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3 784ea272257SMauro Carvalho Chehab { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16 785ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2 786ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4 787ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4 788ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4 789ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4 790ea272257SMauro Carvalho Chehab { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6 791ea272257SMauro Carvalho Chehab { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2 792ea272257SMauro Carvalho Chehab { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4 793ea272257SMauro Carvalho Chehab { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6 794ea272257SMauro Carvalho Chehab 795ea272257SMauro Carvalho Chehab Totals: 796ea272257SMauro Carvalho Chehab Hits: 31536 797ea272257SMauro Carvalho Chehab Entries: 323 798ea272257SMauro Carvalho Chehab Dropped: 0 799ea272257SMauro Carvalho Chehab 800ea272257SMauro Carvalho Chehab The above list does give us a breakdown of the ioctl syscall by 801ea272257SMauro Carvalho Chehab pid, but it also gives us quite a bit more than that, which we 802ea272257SMauro Carvalho Chehab don't really care about at the moment. Since we know the syscall 803ea272257SMauro Carvalho Chehab id for sys_ioctl (16, displayed next to the sys_ioctl name), we 804ea272257SMauro Carvalho Chehab can use that to filter out all the other syscalls:: 805ea272257SMauro Carvalho Chehab 806ea272257SMauro Carvalho Chehab # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \ 8072abfcd29SRoss Zwisler /sys/kernel/tracing/events/raw_syscalls/sys_enter/trigger 808ea272257SMauro Carvalho Chehab 8092abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/raw_syscalls/sys_enter/hist 810ea272257SMauro Carvalho Chehab # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active] 811ea272257SMauro Carvalho Chehab 812ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1 813ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1 814ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1 815ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1 816ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1 817ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1 818ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1 819ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1 820ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1 821ea272257SMauro Carvalho Chehab . 822ea272257SMauro Carvalho Chehab . 823ea272257SMauro Carvalho Chehab . 824ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45 825ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48 826ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48 827ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66 828ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674 829ea272257SMauro Carvalho Chehab { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443 830ea272257SMauro Carvalho Chehab 831ea272257SMauro Carvalho Chehab Totals: 832ea272257SMauro Carvalho Chehab Hits: 101162 833ea272257SMauro Carvalho Chehab Entries: 103 834ea272257SMauro Carvalho Chehab Dropped: 0 835ea272257SMauro Carvalho Chehab 836ea272257SMauro Carvalho Chehab The above output shows that 'compiz' and 'Xorg' are far and away 837ea272257SMauro Carvalho Chehab the heaviest ioctl callers (which might lead to questions about 838ea272257SMauro Carvalho Chehab whether they really need to be making all those calls and to 839ea272257SMauro Carvalho Chehab possible avenues for further investigation.) 840ea272257SMauro Carvalho Chehab 841ea272257SMauro Carvalho Chehab The compound key examples used a key and a sum value (hitcount) to 842ea272257SMauro Carvalho Chehab sort the output, but we can just as easily use two keys instead. 843ea272257SMauro Carvalho Chehab Here's an example where we use a compound key composed of the the 844ea272257SMauro Carvalho Chehab common_pid and size event fields. Sorting with pid as the primary 845ea272257SMauro Carvalho Chehab key and 'size' as the secondary key allows us to display an 846ea272257SMauro Carvalho Chehab ordered summary of the recvfrom sizes, with counts, received by 847ea272257SMauro Carvalho Chehab each process:: 848ea272257SMauro Carvalho Chehab 849ea272257SMauro Carvalho Chehab # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \ 8502abfcd29SRoss Zwisler /sys/kernel/tracing/events/syscalls/sys_enter_recvfrom/trigger 851ea272257SMauro Carvalho Chehab 8522abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/syscalls/sys_enter_recvfrom/hist 853ea272257SMauro Carvalho Chehab # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active] 854ea272257SMauro Carvalho Chehab 855ea272257SMauro Carvalho Chehab { common_pid: smbd [ 784], size: 4 } hitcount: 1 856ea272257SMauro Carvalho Chehab { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672 857ea272257SMauro Carvalho Chehab { common_pid: postgres [ 1796], size: 1000 } hitcount: 6 858ea272257SMauro Carvalho Chehab { common_pid: postgres [ 1867], size: 1000 } hitcount: 10 859ea272257SMauro Carvalho Chehab { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2 860ea272257SMauro Carvalho Chehab { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1 861ea272257SMauro Carvalho Chehab { common_pid: compiz [ 2994], size: 8 } hitcount: 1 862ea272257SMauro Carvalho Chehab { common_pid: compiz [ 2994], size: 20 } hitcount: 11 863ea272257SMauro Carvalho Chehab { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2 864ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 4 } hitcount: 1 865ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 8 } hitcount: 5 866ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 588 } hitcount: 2 867ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 628 } hitcount: 1 868ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 6944 } hitcount: 1 869ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8817], size: 408880 } hitcount: 2 870ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8822], size: 8 } hitcount: 2 871ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8822], size: 160 } hitcount: 2 872ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8822], size: 320 } hitcount: 2 873ea272257SMauro Carvalho Chehab { common_pid: firefox [ 8822], size: 352 } hitcount: 1 874ea272257SMauro Carvalho Chehab . 875ea272257SMauro Carvalho Chehab . 876ea272257SMauro Carvalho Chehab . 877ea272257SMauro Carvalho Chehab { common_pid: pool [ 8923], size: 1960 } hitcount: 10 878ea272257SMauro Carvalho Chehab { common_pid: pool [ 8923], size: 2048 } hitcount: 10 879ea272257SMauro Carvalho Chehab { common_pid: pool [ 8924], size: 1960 } hitcount: 10 880ea272257SMauro Carvalho Chehab { common_pid: pool [ 8924], size: 2048 } hitcount: 10 881ea272257SMauro Carvalho Chehab { common_pid: pool [ 8928], size: 1964 } hitcount: 4 882ea272257SMauro Carvalho Chehab { common_pid: pool [ 8928], size: 1965 } hitcount: 2 883ea272257SMauro Carvalho Chehab { common_pid: pool [ 8928], size: 2048 } hitcount: 6 884ea272257SMauro Carvalho Chehab { common_pid: pool [ 8929], size: 1982 } hitcount: 1 885ea272257SMauro Carvalho Chehab { common_pid: pool [ 8929], size: 2048 } hitcount: 1 886ea272257SMauro Carvalho Chehab 887ea272257SMauro Carvalho Chehab Totals: 888ea272257SMauro Carvalho Chehab Hits: 2016 889ea272257SMauro Carvalho Chehab Entries: 224 890ea272257SMauro Carvalho Chehab Dropped: 0 891ea272257SMauro Carvalho Chehab 892ea272257SMauro Carvalho Chehab The above example also illustrates the fact that although a compound 893ea272257SMauro Carvalho Chehab key is treated as a single entity for hashing purposes, the sub-keys 894ea272257SMauro Carvalho Chehab it's composed of can be accessed independently. 895ea272257SMauro Carvalho Chehab 896ea272257SMauro Carvalho Chehab The next example uses a string field as the hash key and 897ea272257SMauro Carvalho Chehab demonstrates how you can manually pause and continue a hist trigger. 898ea272257SMauro Carvalho Chehab In this example, we'll aggregate fork counts and don't expect a 899ea272257SMauro Carvalho Chehab large number of entries in the hash table, so we'll drop it to a 900ea272257SMauro Carvalho Chehab much smaller number, say 256:: 901ea272257SMauro Carvalho Chehab 902ea272257SMauro Carvalho Chehab # echo 'hist:key=child_comm:val=hitcount:size=256' > \ 9032abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_fork/trigger 904ea272257SMauro Carvalho Chehab 9052abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_fork/hist 906ea272257SMauro Carvalho Chehab # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] 907ea272257SMauro Carvalho Chehab 908ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 909ea272257SMauro Carvalho Chehab { child_comm: ibus-daemon } hitcount: 1 910ea272257SMauro Carvalho Chehab { child_comm: whoopsie } hitcount: 1 911ea272257SMauro Carvalho Chehab { child_comm: smbd } hitcount: 1 912ea272257SMauro Carvalho Chehab { child_comm: gdbus } hitcount: 1 913ea272257SMauro Carvalho Chehab { child_comm: kthreadd } hitcount: 1 914ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 915ea272257SMauro Carvalho Chehab { child_comm: evolution-alarm } hitcount: 2 916ea272257SMauro Carvalho Chehab { child_comm: Socket Thread } hitcount: 2 917ea272257SMauro Carvalho Chehab { child_comm: postgres } hitcount: 2 918ea272257SMauro Carvalho Chehab { child_comm: bash } hitcount: 3 919ea272257SMauro Carvalho Chehab { child_comm: compiz } hitcount: 3 920ea272257SMauro Carvalho Chehab { child_comm: evolution-sourc } hitcount: 4 921ea272257SMauro Carvalho Chehab { child_comm: dhclient } hitcount: 4 922ea272257SMauro Carvalho Chehab { child_comm: pool } hitcount: 5 923ea272257SMauro Carvalho Chehab { child_comm: nm-dispatcher.a } hitcount: 8 924ea272257SMauro Carvalho Chehab { child_comm: firefox } hitcount: 8 925ea272257SMauro Carvalho Chehab { child_comm: dbus-daemon } hitcount: 8 926ea272257SMauro Carvalho Chehab { child_comm: glib-pacrunner } hitcount: 10 927ea272257SMauro Carvalho Chehab { child_comm: evolution } hitcount: 23 928ea272257SMauro Carvalho Chehab 929ea272257SMauro Carvalho Chehab Totals: 930ea272257SMauro Carvalho Chehab Hits: 89 931ea272257SMauro Carvalho Chehab Entries: 20 932ea272257SMauro Carvalho Chehab Dropped: 0 933ea272257SMauro Carvalho Chehab 934ea272257SMauro Carvalho Chehab If we want to pause the hist trigger, we can simply append :pause to 935ea272257SMauro Carvalho Chehab the command that started the trigger. Notice that the trigger info 936ea272257SMauro Carvalho Chehab displays as [paused]:: 937ea272257SMauro Carvalho Chehab 938ea272257SMauro Carvalho Chehab # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \ 9392abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_fork/trigger 940ea272257SMauro Carvalho Chehab 9412abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_fork/hist 942ea272257SMauro Carvalho Chehab # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused] 943ea272257SMauro Carvalho Chehab 944ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 945ea272257SMauro Carvalho Chehab { child_comm: kthreadd } hitcount: 1 946ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 947ea272257SMauro Carvalho Chehab { child_comm: gdbus } hitcount: 1 948ea272257SMauro Carvalho Chehab { child_comm: ibus-daemon } hitcount: 1 949ea272257SMauro Carvalho Chehab { child_comm: Socket Thread } hitcount: 2 950ea272257SMauro Carvalho Chehab { child_comm: evolution-alarm } hitcount: 2 951ea272257SMauro Carvalho Chehab { child_comm: smbd } hitcount: 2 952ea272257SMauro Carvalho Chehab { child_comm: bash } hitcount: 3 953ea272257SMauro Carvalho Chehab { child_comm: whoopsie } hitcount: 3 954ea272257SMauro Carvalho Chehab { child_comm: compiz } hitcount: 3 955ea272257SMauro Carvalho Chehab { child_comm: evolution-sourc } hitcount: 4 956ea272257SMauro Carvalho Chehab { child_comm: pool } hitcount: 5 957ea272257SMauro Carvalho Chehab { child_comm: postgres } hitcount: 6 958ea272257SMauro Carvalho Chehab { child_comm: firefox } hitcount: 8 959ea272257SMauro Carvalho Chehab { child_comm: dhclient } hitcount: 10 960ea272257SMauro Carvalho Chehab { child_comm: emacs } hitcount: 12 961ea272257SMauro Carvalho Chehab { child_comm: dbus-daemon } hitcount: 20 962ea272257SMauro Carvalho Chehab { child_comm: nm-dispatcher.a } hitcount: 20 963ea272257SMauro Carvalho Chehab { child_comm: evolution } hitcount: 35 964ea272257SMauro Carvalho Chehab { child_comm: glib-pacrunner } hitcount: 59 965ea272257SMauro Carvalho Chehab 966ea272257SMauro Carvalho Chehab Totals: 967ea272257SMauro Carvalho Chehab Hits: 199 968ea272257SMauro Carvalho Chehab Entries: 21 969ea272257SMauro Carvalho Chehab Dropped: 0 970ea272257SMauro Carvalho Chehab 971ea272257SMauro Carvalho Chehab To manually continue having the trigger aggregate events, append 972ea272257SMauro Carvalho Chehab :cont instead. Notice that the trigger info displays as [active] 973ea272257SMauro Carvalho Chehab again, and the data has changed:: 974ea272257SMauro Carvalho Chehab 975ea272257SMauro Carvalho Chehab # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \ 9762abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_fork/trigger 977ea272257SMauro Carvalho Chehab 9782abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_fork/hist 979ea272257SMauro Carvalho Chehab # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] 980ea272257SMauro Carvalho Chehab 981ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 982ea272257SMauro Carvalho Chehab { child_comm: dconf worker } hitcount: 1 983ea272257SMauro Carvalho Chehab { child_comm: kthreadd } hitcount: 1 984ea272257SMauro Carvalho Chehab { child_comm: gdbus } hitcount: 1 985ea272257SMauro Carvalho Chehab { child_comm: ibus-daemon } hitcount: 1 986ea272257SMauro Carvalho Chehab { child_comm: Socket Thread } hitcount: 2 987ea272257SMauro Carvalho Chehab { child_comm: evolution-alarm } hitcount: 2 988ea272257SMauro Carvalho Chehab { child_comm: smbd } hitcount: 2 989ea272257SMauro Carvalho Chehab { child_comm: whoopsie } hitcount: 3 990ea272257SMauro Carvalho Chehab { child_comm: compiz } hitcount: 3 991ea272257SMauro Carvalho Chehab { child_comm: evolution-sourc } hitcount: 4 992ea272257SMauro Carvalho Chehab { child_comm: bash } hitcount: 5 993ea272257SMauro Carvalho Chehab { child_comm: pool } hitcount: 5 994ea272257SMauro Carvalho Chehab { child_comm: postgres } hitcount: 6 995ea272257SMauro Carvalho Chehab { child_comm: firefox } hitcount: 8 996ea272257SMauro Carvalho Chehab { child_comm: dhclient } hitcount: 11 997ea272257SMauro Carvalho Chehab { child_comm: emacs } hitcount: 12 998ea272257SMauro Carvalho Chehab { child_comm: dbus-daemon } hitcount: 22 999ea272257SMauro Carvalho Chehab { child_comm: nm-dispatcher.a } hitcount: 22 1000ea272257SMauro Carvalho Chehab { child_comm: evolution } hitcount: 35 1001ea272257SMauro Carvalho Chehab { child_comm: glib-pacrunner } hitcount: 59 1002ea272257SMauro Carvalho Chehab 1003ea272257SMauro Carvalho Chehab Totals: 1004ea272257SMauro Carvalho Chehab Hits: 206 1005ea272257SMauro Carvalho Chehab Entries: 21 1006ea272257SMauro Carvalho Chehab Dropped: 0 1007ea272257SMauro Carvalho Chehab 1008ea272257SMauro Carvalho Chehab The previous example showed how to start and stop a hist trigger by 1009ea272257SMauro Carvalho Chehab appending 'pause' and 'continue' to the hist trigger command. A 1010ea272257SMauro Carvalho Chehab hist trigger can also be started in a paused state by initially 1011ea272257SMauro Carvalho Chehab starting the trigger with ':pause' appended. This allows you to 1012ea272257SMauro Carvalho Chehab start the trigger only when you're ready to start collecting data 1013ea272257SMauro Carvalho Chehab and not before. For example, you could start the trigger in a 1014ea272257SMauro Carvalho Chehab paused state, then unpause it and do something you want to measure, 1015ea272257SMauro Carvalho Chehab then pause the trigger again when done. 1016ea272257SMauro Carvalho Chehab 1017ea272257SMauro Carvalho Chehab Of course, doing this manually can be difficult and error-prone, but 1018ea272257SMauro Carvalho Chehab it is possible to automatically start and stop a hist trigger based 1019ea272257SMauro Carvalho Chehab on some condition, via the enable_hist and disable_hist triggers. 1020ea272257SMauro Carvalho Chehab 1021ea272257SMauro Carvalho Chehab For example, suppose we wanted to take a look at the relative 1022ea272257SMauro Carvalho Chehab weights in terms of skb length for each callpath that leads to a 1023fe4ec72cSMasanari Iida netif_receive_skb event when downloading a decent-sized file using 1024ea272257SMauro Carvalho Chehab wget. 1025ea272257SMauro Carvalho Chehab 1026ea272257SMauro Carvalho Chehab First we set up an initially paused stacktrace trigger on the 1027ea272257SMauro Carvalho Chehab netif_receive_skb event:: 1028ea272257SMauro Carvalho Chehab 1029*4b512860SSteven Rostedt (Google) # echo 'hist:key=common_stacktrace:vals=len:pause' > \ 10302abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1031ea272257SMauro Carvalho Chehab 1032ea272257SMauro Carvalho Chehab Next, we set up an 'enable_hist' trigger on the sched_process_exec 1033ea272257SMauro Carvalho Chehab event, with an 'if filename==/usr/bin/wget' filter. The effect of 1034ea272257SMauro Carvalho Chehab this new trigger is that it will 'unpause' the hist trigger we just 1035ea272257SMauro Carvalho Chehab set up on netif_receive_skb if and only if it sees a 1036ea272257SMauro Carvalho Chehab sched_process_exec event with a filename of '/usr/bin/wget'. When 1037ea272257SMauro Carvalho Chehab that happens, all netif_receive_skb events are aggregated into a 1038ea272257SMauro Carvalho Chehab hash table keyed on stacktrace:: 1039ea272257SMauro Carvalho Chehab 1040ea272257SMauro Carvalho Chehab # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ 10412abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exec/trigger 1042ea272257SMauro Carvalho Chehab 1043ea272257SMauro Carvalho Chehab The aggregation continues until the netif_receive_skb is paused 1044ea272257SMauro Carvalho Chehab again, which is what the following disable_hist event does by 1045ea272257SMauro Carvalho Chehab creating a similar setup on the sched_process_exit event, using the 1046ea272257SMauro Carvalho Chehab filter 'comm==wget':: 1047ea272257SMauro Carvalho Chehab 1048ea272257SMauro Carvalho Chehab # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ 10492abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exit/trigger 1050ea272257SMauro Carvalho Chehab 1051ea272257SMauro Carvalho Chehab Whenever a process exits and the comm field of the disable_hist 1052ea272257SMauro Carvalho Chehab trigger filter matches 'comm==wget', the netif_receive_skb hist 1053ea272257SMauro Carvalho Chehab trigger is disabled. 1054ea272257SMauro Carvalho Chehab 1055ea272257SMauro Carvalho Chehab The overall effect is that netif_receive_skb events are aggregated 1056ea272257SMauro Carvalho Chehab into the hash table for only the duration of the wget. Executing a 1057ea272257SMauro Carvalho Chehab wget command and then listing the 'hist' file will display the 1058ea272257SMauro Carvalho Chehab output generated by the wget command:: 1059ea272257SMauro Carvalho Chehab 1060ea272257SMauro Carvalho Chehab $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz 1061ea272257SMauro Carvalho Chehab 10622abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist 1063*4b512860SSteven Rostedt (Google) # trigger info: hist:keys=common_stacktrace:vals=len:sort=hitcount:size=2048 [paused] 1064ea272257SMauro Carvalho Chehab 1065*4b512860SSteven Rostedt (Google) { common_stacktrace: 1066ea272257SMauro Carvalho Chehab __netif_receive_skb_core+0x46d/0x990 1067ea272257SMauro Carvalho Chehab __netif_receive_skb+0x18/0x60 1068ea272257SMauro Carvalho Chehab netif_receive_skb_internal+0x23/0x90 1069ea272257SMauro Carvalho Chehab napi_gro_receive+0xc8/0x100 1070ea272257SMauro Carvalho Chehab ieee80211_deliver_skb+0xd6/0x270 [mac80211] 1071ea272257SMauro Carvalho Chehab ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] 1072ea272257SMauro Carvalho Chehab ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] 1073ea272257SMauro Carvalho Chehab ieee80211_rx+0x31d/0x900 [mac80211] 1074ea272257SMauro Carvalho Chehab iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] 1075ea272257SMauro Carvalho Chehab iwl_rx_dispatch+0x8e/0xf0 [iwldvm] 1076ea272257SMauro Carvalho Chehab iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] 1077ea272257SMauro Carvalho Chehab irq_thread_fn+0x20/0x50 1078ea272257SMauro Carvalho Chehab irq_thread+0x11f/0x150 1079ea272257SMauro Carvalho Chehab kthread+0xd2/0xf0 1080ea272257SMauro Carvalho Chehab ret_from_fork+0x42/0x70 1081ea272257SMauro Carvalho Chehab } hitcount: 85 len: 28884 1082*4b512860SSteven Rostedt (Google) { common_stacktrace: 1083ea272257SMauro Carvalho Chehab __netif_receive_skb_core+0x46d/0x990 1084ea272257SMauro Carvalho Chehab __netif_receive_skb+0x18/0x60 1085ea272257SMauro Carvalho Chehab netif_receive_skb_internal+0x23/0x90 1086ea272257SMauro Carvalho Chehab napi_gro_complete+0xa4/0xe0 1087ea272257SMauro Carvalho Chehab dev_gro_receive+0x23a/0x360 1088ea272257SMauro Carvalho Chehab napi_gro_receive+0x30/0x100 1089ea272257SMauro Carvalho Chehab ieee80211_deliver_skb+0xd6/0x270 [mac80211] 1090ea272257SMauro Carvalho Chehab ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] 1091ea272257SMauro Carvalho Chehab ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] 1092ea272257SMauro Carvalho Chehab ieee80211_rx+0x31d/0x900 [mac80211] 1093ea272257SMauro Carvalho Chehab iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] 1094ea272257SMauro Carvalho Chehab iwl_rx_dispatch+0x8e/0xf0 [iwldvm] 1095ea272257SMauro Carvalho Chehab iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] 1096ea272257SMauro Carvalho Chehab irq_thread_fn+0x20/0x50 1097ea272257SMauro Carvalho Chehab irq_thread+0x11f/0x150 1098ea272257SMauro Carvalho Chehab kthread+0xd2/0xf0 1099ea272257SMauro Carvalho Chehab } hitcount: 98 len: 664329 1100*4b512860SSteven Rostedt (Google) { common_stacktrace: 1101ea272257SMauro Carvalho Chehab __netif_receive_skb_core+0x46d/0x990 1102ea272257SMauro Carvalho Chehab __netif_receive_skb+0x18/0x60 1103ea272257SMauro Carvalho Chehab process_backlog+0xa8/0x150 1104ea272257SMauro Carvalho Chehab net_rx_action+0x15d/0x340 1105ea272257SMauro Carvalho Chehab __do_softirq+0x114/0x2c0 1106ea272257SMauro Carvalho Chehab do_softirq_own_stack+0x1c/0x30 1107ea272257SMauro Carvalho Chehab do_softirq+0x65/0x70 1108ea272257SMauro Carvalho Chehab __local_bh_enable_ip+0xb5/0xc0 1109ea272257SMauro Carvalho Chehab ip_finish_output+0x1f4/0x840 1110ea272257SMauro Carvalho Chehab ip_output+0x6b/0xc0 1111ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1112ea272257SMauro Carvalho Chehab ip_send_skb+0x1a/0x50 1113ea272257SMauro Carvalho Chehab udp_send_skb+0x173/0x2a0 1114ea272257SMauro Carvalho Chehab udp_sendmsg+0x2bf/0x9f0 1115ea272257SMauro Carvalho Chehab inet_sendmsg+0x64/0xa0 1116ea272257SMauro Carvalho Chehab sock_sendmsg+0x3d/0x50 1117ea272257SMauro Carvalho Chehab } hitcount: 115 len: 13030 1118*4b512860SSteven Rostedt (Google) { common_stacktrace: 1119ea272257SMauro Carvalho Chehab __netif_receive_skb_core+0x46d/0x990 1120ea272257SMauro Carvalho Chehab __netif_receive_skb+0x18/0x60 1121ea272257SMauro Carvalho Chehab netif_receive_skb_internal+0x23/0x90 1122ea272257SMauro Carvalho Chehab napi_gro_complete+0xa4/0xe0 1123ea272257SMauro Carvalho Chehab napi_gro_flush+0x6d/0x90 1124ea272257SMauro Carvalho Chehab iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi] 1125ea272257SMauro Carvalho Chehab irq_thread_fn+0x20/0x50 1126ea272257SMauro Carvalho Chehab irq_thread+0x11f/0x150 1127ea272257SMauro Carvalho Chehab kthread+0xd2/0xf0 1128ea272257SMauro Carvalho Chehab ret_from_fork+0x42/0x70 1129ea272257SMauro Carvalho Chehab } hitcount: 934 len: 5512212 1130ea272257SMauro Carvalho Chehab 1131ea272257SMauro Carvalho Chehab Totals: 1132ea272257SMauro Carvalho Chehab Hits: 1232 1133ea272257SMauro Carvalho Chehab Entries: 4 1134ea272257SMauro Carvalho Chehab Dropped: 0 1135ea272257SMauro Carvalho Chehab 1136ea272257SMauro Carvalho Chehab The above shows all the netif_receive_skb callpaths and their total 1137ea272257SMauro Carvalho Chehab lengths for the duration of the wget command. 1138ea272257SMauro Carvalho Chehab 1139ea272257SMauro Carvalho Chehab The 'clear' hist trigger param can be used to clear the hash table. 1140ea272257SMauro Carvalho Chehab Suppose we wanted to try another run of the previous example but 1141ea272257SMauro Carvalho Chehab this time also wanted to see the complete list of events that went 1142ea272257SMauro Carvalho Chehab into the histogram. In order to avoid having to set everything up 1143ea272257SMauro Carvalho Chehab again, we can just clear the histogram first:: 1144ea272257SMauro Carvalho Chehab 1145*4b512860SSteven Rostedt (Google) # echo 'hist:key=common_stacktrace:vals=len:clear' >> \ 11462abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1147ea272257SMauro Carvalho Chehab 1148ea272257SMauro Carvalho Chehab Just to verify that it is in fact cleared, here's what we now see in 1149ea272257SMauro Carvalho Chehab the hist file:: 1150ea272257SMauro Carvalho Chehab 11512abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist 1152*4b512860SSteven Rostedt (Google) # trigger info: hist:keys=common_stacktrace:vals=len:sort=hitcount:size=2048 [paused] 1153ea272257SMauro Carvalho Chehab 1154ea272257SMauro Carvalho Chehab Totals: 1155ea272257SMauro Carvalho Chehab Hits: 0 1156ea272257SMauro Carvalho Chehab Entries: 0 1157ea272257SMauro Carvalho Chehab Dropped: 0 1158ea272257SMauro Carvalho Chehab 1159ea272257SMauro Carvalho Chehab Since we want to see the detailed list of every netif_receive_skb 1160ea272257SMauro Carvalho Chehab event occurring during the new run, which are in fact the same 1161ea272257SMauro Carvalho Chehab events being aggregated into the hash table, we add some additional 1162ea272257SMauro Carvalho Chehab 'enable_event' events to the triggering sched_process_exec and 1163ea272257SMauro Carvalho Chehab sched_process_exit events as such:: 1164ea272257SMauro Carvalho Chehab 1165ea272257SMauro Carvalho Chehab # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \ 11662abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exec/trigger 1167ea272257SMauro Carvalho Chehab 1168ea272257SMauro Carvalho Chehab # echo 'disable_event:net:netif_receive_skb if comm==wget' > \ 11692abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_exit/trigger 1170ea272257SMauro Carvalho Chehab 1171ea272257SMauro Carvalho Chehab If you read the trigger files for the sched_process_exec and 1172ea272257SMauro Carvalho Chehab sched_process_exit triggers, you should see two triggers for each: 1173ea272257SMauro Carvalho Chehab one enabling/disabling the hist aggregation and the other 1174ea272257SMauro Carvalho Chehab enabling/disabling the logging of events:: 1175ea272257SMauro Carvalho Chehab 11762abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_exec/trigger 1177ea272257SMauro Carvalho Chehab enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget 1178ea272257SMauro Carvalho Chehab enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget 1179ea272257SMauro Carvalho Chehab 11802abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_exit/trigger 1181ea272257SMauro Carvalho Chehab enable_event:net:netif_receive_skb:unlimited if comm==wget 1182ea272257SMauro Carvalho Chehab disable_hist:net:netif_receive_skb:unlimited if comm==wget 1183ea272257SMauro Carvalho Chehab 1184ea272257SMauro Carvalho Chehab In other words, whenever either of the sched_process_exec or 1185ea272257SMauro Carvalho Chehab sched_process_exit events is hit and matches 'wget', it enables or 1186ea272257SMauro Carvalho Chehab disables both the histogram and the event log, and what you end up 1187ea272257SMauro Carvalho Chehab with is a hash table and set of events just covering the specified 1188ea272257SMauro Carvalho Chehab duration. Run the wget command again:: 1189ea272257SMauro Carvalho Chehab 1190ea272257SMauro Carvalho Chehab $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz 1191ea272257SMauro Carvalho Chehab 1192ea272257SMauro Carvalho Chehab Displaying the 'hist' file should show something similar to what you 1193ea272257SMauro Carvalho Chehab saw in the last run, but this time you should also see the 1194ea272257SMauro Carvalho Chehab individual events in the trace file:: 1195ea272257SMauro Carvalho Chehab 11962abfcd29SRoss Zwisler # cat /sys/kernel/tracing/trace 1197ea272257SMauro Carvalho Chehab 1198ea272257SMauro Carvalho Chehab # tracer: nop 1199ea272257SMauro Carvalho Chehab # 1200ea272257SMauro Carvalho Chehab # entries-in-buffer/entries-written: 183/1426 #P:4 1201ea272257SMauro Carvalho Chehab # 1202ea272257SMauro Carvalho Chehab # _-----=> irqs-off 1203ea272257SMauro Carvalho Chehab # / _----=> need-resched 1204ea272257SMauro Carvalho Chehab # | / _---=> hardirq/softirq 1205ea272257SMauro Carvalho Chehab # || / _--=> preempt-depth 1206ea272257SMauro Carvalho Chehab # ||| / delay 1207ea272257SMauro Carvalho Chehab # TASK-PID CPU# |||| TIMESTAMP FUNCTION 1208ea272257SMauro Carvalho Chehab # | | | |||| | | 1209ea272257SMauro Carvalho Chehab wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60 1210ea272257SMauro Carvalho Chehab wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60 1211ea272257SMauro Carvalho Chehab dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130 1212ea272257SMauro Carvalho Chehab dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138 1213ea272257SMauro Carvalho Chehab ##### CPU 2 buffer started #### 1214ea272257SMauro Carvalho Chehab irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948 1215ea272257SMauro Carvalho Chehab irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500 1216ea272257SMauro Carvalho Chehab irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948 1217ea272257SMauro Carvalho Chehab irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948 1218ea272257SMauro Carvalho Chehab irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500 1219ea272257SMauro Carvalho Chehab . 1220ea272257SMauro Carvalho Chehab . 1221ea272257SMauro Carvalho Chehab . 1222ea272257SMauro Carvalho Chehab 1223ea272257SMauro Carvalho Chehab The following example demonstrates how multiple hist triggers can be 1224ea272257SMauro Carvalho Chehab attached to a given event. This capability can be useful for 1225ea272257SMauro Carvalho Chehab creating a set of different summaries derived from the same set of 1226ea272257SMauro Carvalho Chehab events, or for comparing the effects of different filters, among 1227ea272257SMauro Carvalho Chehab other things:: 1228ea272257SMauro Carvalho Chehab 1229ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \ 12302abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1231ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \ 12322abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1233ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \ 12342abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1235ea272257SMauro Carvalho Chehab # echo 'hist:keys=skbaddr.hex:vals=len' >> \ 12362abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1237ea272257SMauro Carvalho Chehab # echo 'hist:keys=len:vals=common_preempt_count' >> \ 12382abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1239ea272257SMauro Carvalho Chehab 1240ea272257SMauro Carvalho Chehab The above set of commands create four triggers differing only in 1241ea272257SMauro Carvalho Chehab their filters, along with a completely different though fairly 1242ea272257SMauro Carvalho Chehab nonsensical trigger. Note that in order to append multiple hist 1243ea272257SMauro Carvalho Chehab triggers to the same file, you should use the '>>' operator to 1244ea272257SMauro Carvalho Chehab append them ('>' will also add the new hist trigger, but will remove 1245ea272257SMauro Carvalho Chehab any existing hist triggers beforehand). 1246ea272257SMauro Carvalho Chehab 1247ea272257SMauro Carvalho Chehab Displaying the contents of the 'hist' file for the event shows the 1248ea272257SMauro Carvalho Chehab contents of all five histograms:: 1249ea272257SMauro Carvalho Chehab 12502abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist 1251ea272257SMauro Carvalho Chehab 1252ea272257SMauro Carvalho Chehab # event histogram 1253ea272257SMauro Carvalho Chehab # 1254ea272257SMauro Carvalho Chehab # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active] 1255ea272257SMauro Carvalho Chehab # 1256ea272257SMauro Carvalho Chehab 1257ea272257SMauro Carvalho Chehab { len: 176 } hitcount: 1 common_preempt_count: 0 1258ea272257SMauro Carvalho Chehab { len: 223 } hitcount: 1 common_preempt_count: 0 1259ea272257SMauro Carvalho Chehab { len: 4854 } hitcount: 1 common_preempt_count: 0 1260ea272257SMauro Carvalho Chehab { len: 395 } hitcount: 1 common_preempt_count: 0 1261ea272257SMauro Carvalho Chehab { len: 177 } hitcount: 1 common_preempt_count: 0 1262ea272257SMauro Carvalho Chehab { len: 446 } hitcount: 1 common_preempt_count: 0 1263ea272257SMauro Carvalho Chehab { len: 1601 } hitcount: 1 common_preempt_count: 0 1264ea272257SMauro Carvalho Chehab . 1265ea272257SMauro Carvalho Chehab . 1266ea272257SMauro Carvalho Chehab . 1267ea272257SMauro Carvalho Chehab { len: 1280 } hitcount: 66 common_preempt_count: 0 1268ea272257SMauro Carvalho Chehab { len: 116 } hitcount: 81 common_preempt_count: 40 1269ea272257SMauro Carvalho Chehab { len: 708 } hitcount: 112 common_preempt_count: 0 1270ea272257SMauro Carvalho Chehab { len: 46 } hitcount: 221 common_preempt_count: 0 1271ea272257SMauro Carvalho Chehab { len: 1264 } hitcount: 458 common_preempt_count: 0 1272ea272257SMauro Carvalho Chehab 1273ea272257SMauro Carvalho Chehab Totals: 1274ea272257SMauro Carvalho Chehab Hits: 1428 1275ea272257SMauro Carvalho Chehab Entries: 147 1276ea272257SMauro Carvalho Chehab Dropped: 0 1277ea272257SMauro Carvalho Chehab 1278ea272257SMauro Carvalho Chehab 1279ea272257SMauro Carvalho Chehab # event histogram 1280ea272257SMauro Carvalho Chehab # 1281ea272257SMauro Carvalho Chehab # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] 1282ea272257SMauro Carvalho Chehab # 1283ea272257SMauro Carvalho Chehab 1284ea272257SMauro Carvalho Chehab { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130 1285ea272257SMauro Carvalho Chehab { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280 1286ea272257SMauro Carvalho Chehab { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280 1287ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115 1288ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115 1289ea272257SMauro Carvalho Chehab { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46 1290ea272257SMauro Carvalho Chehab { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118 1291ea272257SMauro Carvalho Chehab { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60 1292ea272257SMauro Carvalho Chehab { skbaddr: ffff880100065900 } hitcount: 1 len: 46 1293ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116 1294ea272257SMauro Carvalho Chehab { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280 1295ea272257SMauro Carvalho Chehab { skbaddr: ffff880100064700 } hitcount: 1 len: 365 1296ea272257SMauro Carvalho Chehab { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60 1297ea272257SMauro Carvalho Chehab . 1298ea272257SMauro Carvalho Chehab . 1299ea272257SMauro Carvalho Chehab . 1300ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677 1301ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052 1302ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589 1303ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326 1304ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678 1305ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678 1306ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589 1307ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307 1308ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032 1309ea272257SMauro Carvalho Chehab 1310ea272257SMauro Carvalho Chehab Totals: 1311ea272257SMauro Carvalho Chehab Hits: 1451 1312ea272257SMauro Carvalho Chehab Entries: 318 1313ea272257SMauro Carvalho Chehab Dropped: 0 1314ea272257SMauro Carvalho Chehab 1315ea272257SMauro Carvalho Chehab 1316ea272257SMauro Carvalho Chehab # event histogram 1317ea272257SMauro Carvalho Chehab # 1318ea272257SMauro Carvalho Chehab # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active] 1319ea272257SMauro Carvalho Chehab # 1320ea272257SMauro Carvalho Chehab 1321ea272257SMauro Carvalho Chehab 1322ea272257SMauro Carvalho Chehab Totals: 1323ea272257SMauro Carvalho Chehab Hits: 0 1324ea272257SMauro Carvalho Chehab Entries: 0 1325ea272257SMauro Carvalho Chehab Dropped: 0 1326ea272257SMauro Carvalho Chehab 1327ea272257SMauro Carvalho Chehab 1328ea272257SMauro Carvalho Chehab # event histogram 1329ea272257SMauro Carvalho Chehab # 1330ea272257SMauro Carvalho Chehab # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active] 1331ea272257SMauro Carvalho Chehab # 1332ea272257SMauro Carvalho Chehab 1333ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212 1334ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212 1335ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212 1336ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492 1337ea272257SMauro Carvalho Chehab { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212 1338ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212 1339ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854 1340ea272257SMauro Carvalho Chehab { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636 1341ea272257SMauro Carvalho Chehab { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924 1342ea272257SMauro Carvalho Chehab { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356 1343ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420 1344ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996 1345ea272257SMauro Carvalho Chehab 1346ea272257SMauro Carvalho Chehab Totals: 1347ea272257SMauro Carvalho Chehab Hits: 14 1348ea272257SMauro Carvalho Chehab Entries: 12 1349ea272257SMauro Carvalho Chehab Dropped: 0 1350ea272257SMauro Carvalho Chehab 1351ea272257SMauro Carvalho Chehab 1352ea272257SMauro Carvalho Chehab # event histogram 1353ea272257SMauro Carvalho Chehab # 1354ea272257SMauro Carvalho Chehab # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active] 1355ea272257SMauro Carvalho Chehab # 1356ea272257SMauro Carvalho Chehab 1357ea272257SMauro Carvalho Chehab 1358ea272257SMauro Carvalho Chehab Totals: 1359ea272257SMauro Carvalho Chehab Hits: 0 1360ea272257SMauro Carvalho Chehab Entries: 0 1361ea272257SMauro Carvalho Chehab Dropped: 0 1362ea272257SMauro Carvalho Chehab 1363ea272257SMauro Carvalho Chehab Named triggers can be used to have triggers share a common set of 1364ea272257SMauro Carvalho Chehab histogram data. This capability is mostly useful for combining the 1365ea272257SMauro Carvalho Chehab output of events generated by tracepoints contained inside inline 1366ea272257SMauro Carvalho Chehab functions, but names can be used in a hist trigger on any event. 1367ea272257SMauro Carvalho Chehab For example, these two triggers when hit will update the same 'len' 1368ea272257SMauro Carvalho Chehab field in the shared 'foo' histogram data:: 1369ea272257SMauro Carvalho Chehab 1370ea272257SMauro Carvalho Chehab # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ 13712abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_receive_skb/trigger 1372ea272257SMauro Carvalho Chehab # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ 13732abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_rx/trigger 1374ea272257SMauro Carvalho Chehab 1375ea272257SMauro Carvalho Chehab You can see that they're updating common histogram data by reading 1376ea272257SMauro Carvalho Chehab each event's hist files at the same time:: 1377ea272257SMauro Carvalho Chehab 13782abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_receive_skb/hist; 13792abfcd29SRoss Zwisler cat /sys/kernel/tracing/events/net/netif_rx/hist 1380ea272257SMauro Carvalho Chehab 1381ea272257SMauro Carvalho Chehab # event histogram 1382ea272257SMauro Carvalho Chehab # 1383ea272257SMauro Carvalho Chehab # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] 1384ea272257SMauro Carvalho Chehab # 1385ea272257SMauro Carvalho Chehab 1386ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 1387ea272257SMauro Carvalho Chehab { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 1388ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 1389ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 1390ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 1391ea272257SMauro Carvalho Chehab { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 1392ea272257SMauro Carvalho Chehab { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 1393ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 1394ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 1395ea272257SMauro Carvalho Chehab { skbaddr: ffff880064505000 } hitcount: 1 len: 46 1396ea272257SMauro Carvalho Chehab { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 1397ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 1398ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 1399ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 1400ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 1401ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 1402ea272257SMauro Carvalho Chehab { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 1403ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 1404ea272257SMauro Carvalho Chehab { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 1405ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 1406ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 1407ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 1408ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 1409ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 1410ea272257SMauro Carvalho Chehab { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 1411ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 1412ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 1413ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 1414ea272257SMauro Carvalho Chehab { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 1415ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 1416ea272257SMauro Carvalho Chehab { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 1417ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 1418ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 1419ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 1420ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 1421ea272257SMauro Carvalho Chehab { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 1422ea272257SMauro Carvalho Chehab { skbaddr: ffff880064504400 } hitcount: 4 len: 184 1423ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 1424ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 1425ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 1426ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 1427ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 1428ea272257SMauro Carvalho Chehab 1429ea272257SMauro Carvalho Chehab Totals: 1430ea272257SMauro Carvalho Chehab Hits: 81 1431ea272257SMauro Carvalho Chehab Entries: 42 1432ea272257SMauro Carvalho Chehab Dropped: 0 1433ea272257SMauro Carvalho Chehab # event histogram 1434ea272257SMauro Carvalho Chehab # 1435ea272257SMauro Carvalho Chehab # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] 1436ea272257SMauro Carvalho Chehab # 1437ea272257SMauro Carvalho Chehab 1438ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 1439ea272257SMauro Carvalho Chehab { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 1440ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 1441ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 1442ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 1443ea272257SMauro Carvalho Chehab { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 1444ea272257SMauro Carvalho Chehab { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 1445ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 1446ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 1447ea272257SMauro Carvalho Chehab { skbaddr: ffff880064505000 } hitcount: 1 len: 46 1448ea272257SMauro Carvalho Chehab { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 1449ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 1450ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 1451ea272257SMauro Carvalho Chehab { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 1452ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 1453ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 1454ea272257SMauro Carvalho Chehab { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 1455ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 1456ea272257SMauro Carvalho Chehab { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 1457ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 1458ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 1459ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 1460ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 1461ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 1462ea272257SMauro Carvalho Chehab { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 1463ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 1464ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 1465ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 1466ea272257SMauro Carvalho Chehab { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 1467ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 1468ea272257SMauro Carvalho Chehab { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 1469ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 1470ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 1471ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 1472ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 1473ea272257SMauro Carvalho Chehab { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 1474ea272257SMauro Carvalho Chehab { skbaddr: ffff880064504400 } hitcount: 4 len: 184 1475ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 1476ea272257SMauro Carvalho Chehab { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 1477ea272257SMauro Carvalho Chehab { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 1478ea272257SMauro Carvalho Chehab { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 1479ea272257SMauro Carvalho Chehab { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 1480ea272257SMauro Carvalho Chehab 1481ea272257SMauro Carvalho Chehab Totals: 1482ea272257SMauro Carvalho Chehab Hits: 81 1483ea272257SMauro Carvalho Chehab Entries: 42 1484ea272257SMauro Carvalho Chehab Dropped: 0 1485ea272257SMauro Carvalho Chehab 1486ea272257SMauro Carvalho Chehab And here's an example that shows how to combine histogram data from 1487ea272257SMauro Carvalho Chehab any two events even if they don't share any 'compatible' fields 1488*4b512860SSteven Rostedt (Google) other than 'hitcount' and 'common_stacktrace'. These commands create a 1489ea272257SMauro Carvalho Chehab couple of triggers named 'bar' using those fields:: 1490ea272257SMauro Carvalho Chehab 1491*4b512860SSteven Rostedt (Google) # echo 'hist:name=bar:key=common_stacktrace:val=hitcount' > \ 14922abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_process_fork/trigger 1493*4b512860SSteven Rostedt (Google) # echo 'hist:name=bar:key=common_stacktrace:val=hitcount' > \ 14942abfcd29SRoss Zwisler /sys/kernel/tracing/events/net/netif_rx/trigger 1495ea272257SMauro Carvalho Chehab 1496ea272257SMauro Carvalho Chehab And displaying the output of either shows some interesting if 1497ea272257SMauro Carvalho Chehab somewhat confusing output:: 1498ea272257SMauro Carvalho Chehab 14992abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_process_fork/hist 15002abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/net/netif_rx/hist 1501ea272257SMauro Carvalho Chehab 1502ea272257SMauro Carvalho Chehab # event histogram 1503ea272257SMauro Carvalho Chehab # 1504*4b512860SSteven Rostedt (Google) # trigger info: hist:name=bar:keys=common_stacktrace:vals=hitcount:sort=hitcount:size=2048 [active] 1505ea272257SMauro Carvalho Chehab # 1506ea272257SMauro Carvalho Chehab 1507*4b512860SSteven Rostedt (Google) { common_stacktrace: 1508eea11285SChristian Brauner kernel_clone+0x18e/0x330 1509ea272257SMauro Carvalho Chehab kernel_thread+0x29/0x30 1510ea272257SMauro Carvalho Chehab kthreadd+0x154/0x1b0 1511ea272257SMauro Carvalho Chehab ret_from_fork+0x3f/0x70 1512ea272257SMauro Carvalho Chehab } hitcount: 1 1513*4b512860SSteven Rostedt (Google) { common_stacktrace: 1514ea272257SMauro Carvalho Chehab netif_rx_internal+0xb2/0xd0 1515ea272257SMauro Carvalho Chehab netif_rx_ni+0x20/0x70 1516ea272257SMauro Carvalho Chehab dev_loopback_xmit+0xaa/0xd0 1517ea272257SMauro Carvalho Chehab ip_mc_output+0x126/0x240 1518ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1519ea272257SMauro Carvalho Chehab igmp_send_report+0x1e9/0x230 1520ea272257SMauro Carvalho Chehab igmp_timer_expire+0xe9/0x120 1521ea272257SMauro Carvalho Chehab call_timer_fn+0x39/0xf0 1522ea272257SMauro Carvalho Chehab run_timer_softirq+0x1e1/0x290 1523ea272257SMauro Carvalho Chehab __do_softirq+0xfd/0x290 1524ea272257SMauro Carvalho Chehab irq_exit+0x98/0xb0 1525ea272257SMauro Carvalho Chehab smp_apic_timer_interrupt+0x4a/0x60 1526ea272257SMauro Carvalho Chehab apic_timer_interrupt+0x6d/0x80 1527ea272257SMauro Carvalho Chehab cpuidle_enter+0x17/0x20 1528ea272257SMauro Carvalho Chehab call_cpuidle+0x3b/0x60 1529ea272257SMauro Carvalho Chehab cpu_startup_entry+0x22d/0x310 1530ea272257SMauro Carvalho Chehab } hitcount: 1 1531*4b512860SSteven Rostedt (Google) { common_stacktrace: 1532ea272257SMauro Carvalho Chehab netif_rx_internal+0xb2/0xd0 1533ea272257SMauro Carvalho Chehab netif_rx_ni+0x20/0x70 1534ea272257SMauro Carvalho Chehab dev_loopback_xmit+0xaa/0xd0 1535ea272257SMauro Carvalho Chehab ip_mc_output+0x17f/0x240 1536ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1537ea272257SMauro Carvalho Chehab ip_send_skb+0x1a/0x50 1538ea272257SMauro Carvalho Chehab udp_send_skb+0x13e/0x270 1539ea272257SMauro Carvalho Chehab udp_sendmsg+0x2bf/0x980 1540ea272257SMauro Carvalho Chehab inet_sendmsg+0x67/0xa0 1541ea272257SMauro Carvalho Chehab sock_sendmsg+0x38/0x50 1542ea272257SMauro Carvalho Chehab SYSC_sendto+0xef/0x170 1543ea272257SMauro Carvalho Chehab SyS_sendto+0xe/0x10 1544ea272257SMauro Carvalho Chehab entry_SYSCALL_64_fastpath+0x12/0x6a 1545ea272257SMauro Carvalho Chehab } hitcount: 2 1546*4b512860SSteven Rostedt (Google) { common_stacktrace: 1547ea272257SMauro Carvalho Chehab netif_rx_internal+0xb2/0xd0 1548ea272257SMauro Carvalho Chehab netif_rx+0x1c/0x60 1549ea272257SMauro Carvalho Chehab loopback_xmit+0x6c/0xb0 1550ea272257SMauro Carvalho Chehab dev_hard_start_xmit+0x219/0x3a0 1551ea272257SMauro Carvalho Chehab __dev_queue_xmit+0x415/0x4f0 1552ea272257SMauro Carvalho Chehab dev_queue_xmit_sk+0x13/0x20 1553ea272257SMauro Carvalho Chehab ip_finish_output2+0x237/0x340 1554ea272257SMauro Carvalho Chehab ip_finish_output+0x113/0x1d0 1555ea272257SMauro Carvalho Chehab ip_output+0x66/0xc0 1556ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1557ea272257SMauro Carvalho Chehab ip_send_skb+0x1a/0x50 1558ea272257SMauro Carvalho Chehab udp_send_skb+0x16d/0x270 1559ea272257SMauro Carvalho Chehab udp_sendmsg+0x2bf/0x980 1560ea272257SMauro Carvalho Chehab inet_sendmsg+0x67/0xa0 1561ea272257SMauro Carvalho Chehab sock_sendmsg+0x38/0x50 1562ea272257SMauro Carvalho Chehab ___sys_sendmsg+0x14e/0x270 1563ea272257SMauro Carvalho Chehab } hitcount: 76 1564*4b512860SSteven Rostedt (Google) { common_stacktrace: 1565ea272257SMauro Carvalho Chehab netif_rx_internal+0xb2/0xd0 1566ea272257SMauro Carvalho Chehab netif_rx+0x1c/0x60 1567ea272257SMauro Carvalho Chehab loopback_xmit+0x6c/0xb0 1568ea272257SMauro Carvalho Chehab dev_hard_start_xmit+0x219/0x3a0 1569ea272257SMauro Carvalho Chehab __dev_queue_xmit+0x415/0x4f0 1570ea272257SMauro Carvalho Chehab dev_queue_xmit_sk+0x13/0x20 1571ea272257SMauro Carvalho Chehab ip_finish_output2+0x237/0x340 1572ea272257SMauro Carvalho Chehab ip_finish_output+0x113/0x1d0 1573ea272257SMauro Carvalho Chehab ip_output+0x66/0xc0 1574ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1575ea272257SMauro Carvalho Chehab ip_send_skb+0x1a/0x50 1576ea272257SMauro Carvalho Chehab udp_send_skb+0x16d/0x270 1577ea272257SMauro Carvalho Chehab udp_sendmsg+0x2bf/0x980 1578ea272257SMauro Carvalho Chehab inet_sendmsg+0x67/0xa0 1579ea272257SMauro Carvalho Chehab sock_sendmsg+0x38/0x50 1580ea272257SMauro Carvalho Chehab ___sys_sendmsg+0x269/0x270 1581ea272257SMauro Carvalho Chehab } hitcount: 77 1582*4b512860SSteven Rostedt (Google) { common_stacktrace: 1583ea272257SMauro Carvalho Chehab netif_rx_internal+0xb2/0xd0 1584ea272257SMauro Carvalho Chehab netif_rx+0x1c/0x60 1585ea272257SMauro Carvalho Chehab loopback_xmit+0x6c/0xb0 1586ea272257SMauro Carvalho Chehab dev_hard_start_xmit+0x219/0x3a0 1587ea272257SMauro Carvalho Chehab __dev_queue_xmit+0x415/0x4f0 1588ea272257SMauro Carvalho Chehab dev_queue_xmit_sk+0x13/0x20 1589ea272257SMauro Carvalho Chehab ip_finish_output2+0x237/0x340 1590ea272257SMauro Carvalho Chehab ip_finish_output+0x113/0x1d0 1591ea272257SMauro Carvalho Chehab ip_output+0x66/0xc0 1592ea272257SMauro Carvalho Chehab ip_local_out_sk+0x31/0x40 1593ea272257SMauro Carvalho Chehab ip_send_skb+0x1a/0x50 1594ea272257SMauro Carvalho Chehab udp_send_skb+0x16d/0x270 1595ea272257SMauro Carvalho Chehab udp_sendmsg+0x2bf/0x980 1596ea272257SMauro Carvalho Chehab inet_sendmsg+0x67/0xa0 1597ea272257SMauro Carvalho Chehab sock_sendmsg+0x38/0x50 1598ea272257SMauro Carvalho Chehab SYSC_sendto+0xef/0x170 1599ea272257SMauro Carvalho Chehab } hitcount: 88 1600*4b512860SSteven Rostedt (Google) { common_stacktrace: 1601eea11285SChristian Brauner kernel_clone+0x18e/0x330 1602ea272257SMauro Carvalho Chehab SyS_clone+0x19/0x20 1603ea272257SMauro Carvalho Chehab entry_SYSCALL_64_fastpath+0x12/0x6a 1604ea272257SMauro Carvalho Chehab } hitcount: 244 1605ea272257SMauro Carvalho Chehab 1606ea272257SMauro Carvalho Chehab Totals: 1607ea272257SMauro Carvalho Chehab Hits: 489 1608ea272257SMauro Carvalho Chehab Entries: 7 1609ea272257SMauro Carvalho Chehab Dropped: 0 1610ea272257SMauro Carvalho Chehab 1611ea272257SMauro Carvalho Chehab2.2 Inter-event hist triggers 1612ea272257SMauro Carvalho Chehab----------------------------- 1613ea272257SMauro Carvalho Chehab 1614ea272257SMauro Carvalho ChehabInter-event hist triggers are hist triggers that combine values from 1615ea272257SMauro Carvalho Chehabone or more other events and create a histogram using that data. Data 1616ea272257SMauro Carvalho Chehabfrom an inter-event histogram can in turn become the source for 1617ea272257SMauro Carvalho Chehabfurther combined histograms, thus providing a chain of related 1618ea272257SMauro Carvalho Chehabhistograms, which is important for some applications. 1619ea272257SMauro Carvalho Chehab 1620ea272257SMauro Carvalho ChehabThe most important example of an inter-event quantity that can be used 1621ea272257SMauro Carvalho Chehabin this manner is latency, which is simply a difference in timestamps 1622ea272257SMauro Carvalho Chehabbetween two events. Although latency is the most important 1623ea272257SMauro Carvalho Chehabinter-event quantity, note that because the support is completely 1624ea272257SMauro Carvalho Chehabgeneral across the trace event subsystem, any event field can be used 1625ea272257SMauro Carvalho Chehabin an inter-event quantity. 1626ea272257SMauro Carvalho Chehab 1627ea272257SMauro Carvalho ChehabAn example of a histogram that combines data from other histograms 1628ea272257SMauro Carvalho Chehabinto a useful chain would be a 'wakeupswitch latency' histogram that 1629ea272257SMauro Carvalho Chehabcombines a 'wakeup latency' histogram and a 'switch latency' 1630ea272257SMauro Carvalho Chehabhistogram. 1631ea272257SMauro Carvalho Chehab 1632ea272257SMauro Carvalho ChehabNormally, a hist trigger specification consists of a (possibly 1633ea272257SMauro Carvalho Chehabcompound) key along with one or more numeric values, which are 1634ea272257SMauro Carvalho Chehabcontinually updated sums associated with that key. A histogram 1635ea272257SMauro Carvalho Chehabspecification in this case consists of individual key and value 1636ea272257SMauro Carvalho Chehabspecifications that refer to trace event fields associated with a 1637ea272257SMauro Carvalho Chehabsingle event type. 1638ea272257SMauro Carvalho Chehab 1639ea272257SMauro Carvalho ChehabThe inter-event hist trigger extension allows fields from multiple 1640ea272257SMauro Carvalho Chehabevents to be referenced and combined into a multi-event histogram 1641ea272257SMauro Carvalho Chehabspecification. In support of this overall goal, a few enabling 1642ea272257SMauro Carvalho Chehabfeatures have been added to the hist trigger support: 1643ea272257SMauro Carvalho Chehab 1644ea272257SMauro Carvalho Chehab - In order to compute an inter-event quantity, a value from one 1645ea272257SMauro Carvalho Chehab event needs to saved and then referenced from another event. This 1646ea272257SMauro Carvalho Chehab requires the introduction of support for histogram 'variables'. 1647ea272257SMauro Carvalho Chehab 1648ea272257SMauro Carvalho Chehab - The computation of inter-event quantities and their combination 1649ea272257SMauro Carvalho Chehab require some minimal amount of support for applying simple 1650ea272257SMauro Carvalho Chehab expressions to variables (+ and -). 1651ea272257SMauro Carvalho Chehab 1652ea272257SMauro Carvalho Chehab - A histogram consisting of inter-event quantities isn't logically a 1653ea272257SMauro Carvalho Chehab histogram on either event (so having the 'hist' file for either 1654ea272257SMauro Carvalho Chehab event host the histogram output doesn't really make sense). To 1655ea272257SMauro Carvalho Chehab address the idea that the histogram is associated with a 1656ea272257SMauro Carvalho Chehab combination of events, support is added allowing the creation of 1657ea272257SMauro Carvalho Chehab 'synthetic' events that are events derived from other events. 1658ea272257SMauro Carvalho Chehab These synthetic events are full-fledged events just like any other 1659ea272257SMauro Carvalho Chehab and can be used as such, as for instance to create the 1660ea272257SMauro Carvalho Chehab 'combination' histograms mentioned previously. 1661ea272257SMauro Carvalho Chehab 1662ea272257SMauro Carvalho Chehab - A set of 'actions' can be associated with histogram entries - 1663ea272257SMauro Carvalho Chehab these can be used to generate the previously mentioned synthetic 1664ea272257SMauro Carvalho Chehab events, but can also be used for other purposes, such as for 1665ea272257SMauro Carvalho Chehab example saving context when a 'max' latency has been hit. 1666ea272257SMauro Carvalho Chehab 1667ea272257SMauro Carvalho Chehab - Trace events don't have a 'timestamp' associated with them, but 1668ea272257SMauro Carvalho Chehab there is an implicit timestamp saved along with an event in the 1669ea272257SMauro Carvalho Chehab underlying ftrace ring buffer. This timestamp is now exposed as a 1670ea272257SMauro Carvalho Chehab a synthetic field named 'common_timestamp' which can be used in 1671ea272257SMauro Carvalho Chehab histograms as if it were any other event field; it isn't an actual 1672ea272257SMauro Carvalho Chehab field in the trace format but rather is a synthesized value that 1673ea272257SMauro Carvalho Chehab nonetheless can be used as if it were an actual field. By default 1674ea272257SMauro Carvalho Chehab it is in units of nanoseconds; appending '.usecs' to a 1675ea272257SMauro Carvalho Chehab common_timestamp field changes the units to microseconds. 1676ea272257SMauro Carvalho Chehab 1677ea272257SMauro Carvalho ChehabA note on inter-event timestamps: If common_timestamp is used in a 1678ea272257SMauro Carvalho Chehabhistogram, the trace buffer is automatically switched over to using 1679ea272257SMauro Carvalho Chehababsolute timestamps and the "global" trace clock, in order to avoid 1680ea272257SMauro Carvalho Chehabbogus timestamp differences with other clocks that aren't coherent 1681ea272257SMauro Carvalho Chehabacross CPUs. This can be overridden by specifying one of the other 1682ea272257SMauro Carvalho Chehabtrace clocks instead, using the "clock=XXX" hist trigger attribute, 1683ea272257SMauro Carvalho Chehabwhere XXX is any of the clocks listed in the tracing/trace_clock 1684ea272257SMauro Carvalho Chehabpseudo-file. 1685ea272257SMauro Carvalho Chehab 1686ea272257SMauro Carvalho ChehabThese features are described in more detail in the following sections. 1687ea272257SMauro Carvalho Chehab 1688ea272257SMauro Carvalho Chehab2.2.1 Histogram Variables 1689ea272257SMauro Carvalho Chehab------------------------- 1690ea272257SMauro Carvalho Chehab 1691ea272257SMauro Carvalho ChehabVariables are simply named locations used for saving and retrieving 1692ea272257SMauro Carvalho Chehabvalues between matching events. A 'matching' event is defined as an 1693ea272257SMauro Carvalho Chehabevent that has a matching key - if a variable is saved for a histogram 1694ea272257SMauro Carvalho Chehabentry corresponding to that key, any subsequent event with a matching 1695ea272257SMauro Carvalho Chehabkey can access that variable. 1696ea272257SMauro Carvalho Chehab 1697ea272257SMauro Carvalho ChehabA variable's value is normally available to any subsequent event until 1698ea272257SMauro Carvalho Chehabit is set to something else by a subsequent event. The one exception 1699ea272257SMauro Carvalho Chehabto that rule is that any variable used in an expression is essentially 1700ea272257SMauro Carvalho Chehab'read-once' - once it's used by an expression in a subsequent event, 1701ea272257SMauro Carvalho Chehabit's reset to its 'unset' state, which means it can't be used again 1702ea272257SMauro Carvalho Chehabunless it's set again. This ensures not only that an event doesn't 1703ea272257SMauro Carvalho Chehabuse an uninitialized variable in a calculation, but that that variable 1704ea272257SMauro Carvalho Chehabis used only once and not for any unrelated subsequent match. 1705ea272257SMauro Carvalho Chehab 1706ea272257SMauro Carvalho ChehabThe basic syntax for saving a variable is to simply prefix a unique 1707ea272257SMauro Carvalho Chehabvariable name not corresponding to any keyword along with an '=' sign 1708ea272257SMauro Carvalho Chehabto any event field. 1709ea272257SMauro Carvalho Chehab 1710ea272257SMauro Carvalho ChehabEither keys or values can be saved and retrieved in this way. This 1711ea272257SMauro Carvalho Chehabcreates a variable named 'ts0' for a histogram entry with the key 1712ea272257SMauro Carvalho Chehab'next_pid':: 1713ea272257SMauro Carvalho Chehab 1714ea272257SMauro Carvalho Chehab # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ... >> \ 1715ea272257SMauro Carvalho Chehab event/trigger 1716ea272257SMauro Carvalho Chehab 1717ea272257SMauro Carvalho ChehabThe ts0 variable can be accessed by any subsequent event having the 1718ea272257SMauro Carvalho Chehabsame pid as 'next_pid'. 1719ea272257SMauro Carvalho Chehab 1720ea272257SMauro Carvalho ChehabVariable references are formed by prepending the variable name with 1721ea272257SMauro Carvalho Chehabthe '$' sign. Thus for example, the ts0 variable above would be 1722ea272257SMauro Carvalho Chehabreferenced as '$ts0' in expressions. 1723ea272257SMauro Carvalho Chehab 1724ea272257SMauro Carvalho ChehabBecause 'vals=' is used, the common_timestamp variable value above 1725ea272257SMauro Carvalho Chehabwill also be summed as a normal histogram value would (though for a 1726ea272257SMauro Carvalho Chehabtimestamp it makes little sense). 1727ea272257SMauro Carvalho Chehab 1728ea272257SMauro Carvalho ChehabThe below shows that a key value can also be saved in the same way:: 1729ea272257SMauro Carvalho Chehab 1730ea272257SMauro Carvalho Chehab # echo 'hist:timer_pid=common_pid:key=timer_pid ...' >> event/trigger 1731ea272257SMauro Carvalho Chehab 1732ea272257SMauro Carvalho ChehabIf a variable isn't a key variable or prefixed with 'vals=', the 1733ea272257SMauro Carvalho Chehabassociated event field will be saved in a variable but won't be summed 1734ea272257SMauro Carvalho Chehabas a value:: 1735ea272257SMauro Carvalho Chehab 1736ea272257SMauro Carvalho Chehab # echo 'hist:keys=next_pid:ts1=common_timestamp ...' >> event/trigger 1737ea272257SMauro Carvalho Chehab 1738ea272257SMauro Carvalho ChehabMultiple variables can be assigned at the same time. The below would 1739ea272257SMauro Carvalho Chehabresult in both ts0 and b being created as variables, with both 1740ea272257SMauro Carvalho Chehabcommon_timestamp and field1 additionally being summed as values:: 1741ea272257SMauro Carvalho Chehab 1742ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:vals=$ts0,$b:ts0=common_timestamp,b=field1 ...' >> \ 1743ea272257SMauro Carvalho Chehab event/trigger 1744ea272257SMauro Carvalho Chehab 1745ea272257SMauro Carvalho ChehabNote that variable assignments can appear either preceding or 1746ea272257SMauro Carvalho Chehabfollowing their use. The command below behaves identically to the 1747ea272257SMauro Carvalho Chehabcommand above:: 1748ea272257SMauro Carvalho Chehab 1749ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:ts0=common_timestamp,b=field1:vals=$ts0,$b ...' >> \ 1750ea272257SMauro Carvalho Chehab event/trigger 1751ea272257SMauro Carvalho Chehab 1752ea272257SMauro Carvalho ChehabAny number of variables not bound to a 'vals=' prefix can also be 1753ea272257SMauro Carvalho Chehabassigned by simply separating them with colons. Below is the same 1754ea272257SMauro Carvalho Chehabthing but without the values being summed in the histogram:: 1755ea272257SMauro Carvalho Chehab 1756ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:ts0=common_timestamp:b=field1 ...' >> event/trigger 1757ea272257SMauro Carvalho Chehab 1758ea272257SMauro Carvalho ChehabVariables set as above can be referenced and used in expressions on 1759ea272257SMauro Carvalho Chehabanother event. 1760ea272257SMauro Carvalho Chehab 1761ea272257SMauro Carvalho ChehabFor example, here's how a latency can be calculated:: 1762ea272257SMauro Carvalho Chehab 1763ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid,prio:ts0=common_timestamp ...' >> event1/trigger 1764ea272257SMauro Carvalho Chehab # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...' >> event2/trigger 1765ea272257SMauro Carvalho Chehab 1766aea74de4SMasanari IidaIn the first line above, the event's timestamp is saved into the 1767ea272257SMauro Carvalho Chehabvariable ts0. In the next line, ts0 is subtracted from the second 1768ea272257SMauro Carvalho Chehabevent's timestamp to produce the latency, which is then assigned into 1769ea272257SMauro Carvalho Chehabyet another variable, 'wakeup_lat'. The hist trigger below in turn 1770ea272257SMauro Carvalho Chehabmakes use of the wakeup_lat variable to compute a combined latency 1771ea272257SMauro Carvalho Chehabusing the same key and variable from yet another event:: 1772ea272257SMauro Carvalho Chehab 1773ea272257SMauro Carvalho Chehab # echo 'hist:key=pid:wakeupswitch_lat=$wakeup_lat+$switchtime_lat ...' >> event3/trigger 1774ea272257SMauro Carvalho Chehab 17752d2f6d4bSKalesh SinghExpressions support the use of addition, subtraction, multiplication and 177693d76e4aSKalesh Singhdivision operators (+-\*/). 17772d2f6d4bSKalesh Singh 17780ca6d12cSKalesh SinghNote if division by zero cannot be detected at parse time (i.e. the 17790ca6d12cSKalesh Singhdivisor is not a constant), the result will be -1. 17802d2f6d4bSKalesh Singh 17812d2f6d4bSKalesh SinghNumeric constants can also be used directly in an expression:: 17822d2f6d4bSKalesh Singh 17832d2f6d4bSKalesh Singh # echo 'hist:keys=next_pid:timestamp_secs=common_timestamp/1000000 ...' >> event/trigger 17842d2f6d4bSKalesh Singh 17852d2f6d4bSKalesh Singhor assigned to a variable and referenced in a subsequent expression:: 17862d2f6d4bSKalesh Singh 17872d2f6d4bSKalesh Singh # echo 'hist:keys=next_pid:us_per_sec=1000000 ...' >> event/trigger 17882d2f6d4bSKalesh Singh # echo 'hist:keys=next_pid:timestamp_secs=common_timestamp/$us_per_sec ...' >> event/trigger 17892d2f6d4bSKalesh Singh 179088238513SSteven Rostedt (Google)Variables can even hold stacktraces, which are useful with synthetic events. 179188238513SSteven Rostedt (Google) 1792ea272257SMauro Carvalho Chehab2.2.2 Synthetic Events 1793ea272257SMauro Carvalho Chehab---------------------- 1794ea272257SMauro Carvalho Chehab 1795ea272257SMauro Carvalho ChehabSynthetic events are user-defined events generated from hist trigger 1796ea272257SMauro Carvalho Chehabvariables or fields associated with one or more other events. Their 1797ea272257SMauro Carvalho Chehabpurpose is to provide a mechanism for displaying data spanning 1798ea272257SMauro Carvalho Chehabmultiple events consistent with the existing and already familiar 1799ea272257SMauro Carvalho Chehabusage for normal events. 1800ea272257SMauro Carvalho Chehab 1801ea272257SMauro Carvalho ChehabTo define a synthetic event, the user writes a simple specification 1802ea272257SMauro Carvalho Chehabconsisting of the name of the new event along with one or more 1803ea272257SMauro Carvalho Chehabvariables and their types, which can be any valid field type, 1804ea272257SMauro Carvalho Chehabseparated by semicolons, to the tracing/synthetic_events file. 1805ea272257SMauro Carvalho Chehab 1806bd82631dSTom ZanussiSee synth_field_size() for available types. 1807bd82631dSTom Zanussi 1808bd82631dSTom ZanussiIf field_name contains [n], the field is considered to be a static array. 1809bd82631dSTom Zanussi 1810bd82631dSTom ZanussiIf field_names contains[] (no subscript), the field is considered to 1811bd82631dSTom Zanussibe a dynamic array, which will only take as much space in the event as 1812bd82631dSTom Zanussiis required to hold the array. 1813bd82631dSTom Zanussi 1814bd82631dSTom ZanussiA string field can be specified using either the static notation: 1815bd82631dSTom Zanussi 1816bd82631dSTom Zanussi char name[32]; 1817bd82631dSTom Zanussi 1818bd82631dSTom ZanussiOr the dynamic: 1819bd82631dSTom Zanussi 1820bd82631dSTom Zanussi char name[]; 1821bd82631dSTom Zanussi 1822bd82631dSTom ZanussiThe size limit for either is 256. 1823bd82631dSTom Zanussi 1824ea272257SMauro Carvalho ChehabFor instance, the following creates a new event named 'wakeup_latency' 1825ea272257SMauro Carvalho Chehabwith 3 fields: lat, pid, and prio. Each of those fields is simply a 1826ea272257SMauro Carvalho Chehabvariable reference to a variable on another event:: 1827ea272257SMauro Carvalho Chehab 1828ea272257SMauro Carvalho Chehab # echo 'wakeup_latency \ 1829ea272257SMauro Carvalho Chehab u64 lat; \ 1830ea272257SMauro Carvalho Chehab pid_t pid; \ 1831ea272257SMauro Carvalho Chehab int prio' >> \ 18322abfcd29SRoss Zwisler /sys/kernel/tracing/synthetic_events 1833ea272257SMauro Carvalho Chehab 1834ea272257SMauro Carvalho ChehabReading the tracing/synthetic_events file lists all the currently 1835ea272257SMauro Carvalho Chehabdefined synthetic events, in this case the event defined above:: 1836ea272257SMauro Carvalho Chehab 18372abfcd29SRoss Zwisler # cat /sys/kernel/tracing/synthetic_events 1838ea272257SMauro Carvalho Chehab wakeup_latency u64 lat; pid_t pid; int prio 1839ea272257SMauro Carvalho Chehab 1840ea272257SMauro Carvalho ChehabAn existing synthetic event definition can be removed by prepending 1841ea272257SMauro Carvalho Chehabthe command that defined it with a '!':: 1842ea272257SMauro Carvalho Chehab 1843ea272257SMauro Carvalho Chehab # echo '!wakeup_latency u64 lat pid_t pid int prio' >> \ 18442abfcd29SRoss Zwisler /sys/kernel/tracing/synthetic_events 1845ea272257SMauro Carvalho Chehab 1846ea272257SMauro Carvalho ChehabAt this point, there isn't yet an actual 'wakeup_latency' event 1847aea74de4SMasanari Iidainstantiated in the event subsystem - for this to happen, a 'hist 1848ea272257SMauro Carvalho Chehabtrigger action' needs to be instantiated and bound to actual fields 1849ea272257SMauro Carvalho Chehaband variables defined on other events (see Section 2.2.3 below on 1850ea272257SMauro Carvalho Chehabhow that is done using hist trigger 'onmatch' action). Once that is 1851ea272257SMauro Carvalho Chehabdone, the 'wakeup_latency' synthetic event instance is created. 1852ea272257SMauro Carvalho Chehab 1853ea272257SMauro Carvalho ChehabThe new event is created under the tracing/events/synthetic/ directory 1854ea272257SMauro Carvalho Chehaband looks and behaves just like any other event:: 1855ea272257SMauro Carvalho Chehab 18562abfcd29SRoss Zwisler # ls /sys/kernel/tracing/events/synthetic/wakeup_latency 1857ea272257SMauro Carvalho Chehab enable filter format hist id trigger 1858ea272257SMauro Carvalho Chehab 185937036435SSteven Rostedt (VMware)A histogram can now be defined for the new synthetic event:: 186037036435SSteven Rostedt (VMware) 186137036435SSteven Rostedt (VMware) # echo 'hist:keys=pid,prio,lat.log2:sort=lat' >> \ 18622abfcd29SRoss Zwisler /sys/kernel/tracing/events/synthetic/wakeup_latency/trigger 186337036435SSteven Rostedt (VMware) 186437036435SSteven Rostedt (VMware)The above shows the latency "lat" in a power of 2 grouping. 186537036435SSteven Rostedt (VMware) 1866ea272257SMauro Carvalho ChehabLike any other event, once a histogram is enabled for the event, the 1867a2ff84a5SBagas Sanjayaoutput can be displayed by reading the event's 'hist' file:: 1868ea272257SMauro Carvalho Chehab 18692abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/synthetic/wakeup_latency/hist 187037036435SSteven Rostedt (VMware) 187137036435SSteven Rostedt (VMware) # event histogram 187237036435SSteven Rostedt (VMware) # 187337036435SSteven Rostedt (VMware) # trigger info: hist:keys=pid,prio,lat.log2:vals=hitcount:sort=lat.log2:size=2048 [active] 187437036435SSteven Rostedt (VMware) # 187537036435SSteven Rostedt (VMware) 187637036435SSteven Rostedt (VMware) { pid: 2035, prio: 9, lat: ~ 2^2 } hitcount: 43 187737036435SSteven Rostedt (VMware) { pid: 2034, prio: 9, lat: ~ 2^2 } hitcount: 60 187837036435SSteven Rostedt (VMware) { pid: 2029, prio: 9, lat: ~ 2^2 } hitcount: 965 187937036435SSteven Rostedt (VMware) { pid: 2034, prio: 120, lat: ~ 2^2 } hitcount: 9 188037036435SSteven Rostedt (VMware) { pid: 2033, prio: 120, lat: ~ 2^2 } hitcount: 5 188137036435SSteven Rostedt (VMware) { pid: 2030, prio: 9, lat: ~ 2^2 } hitcount: 335 188237036435SSteven Rostedt (VMware) { pid: 2030, prio: 120, lat: ~ 2^2 } hitcount: 10 188337036435SSteven Rostedt (VMware) { pid: 2032, prio: 120, lat: ~ 2^2 } hitcount: 1 188437036435SSteven Rostedt (VMware) { pid: 2035, prio: 120, lat: ~ 2^2 } hitcount: 2 188537036435SSteven Rostedt (VMware) { pid: 2031, prio: 9, lat: ~ 2^2 } hitcount: 176 188637036435SSteven Rostedt (VMware) { pid: 2028, prio: 120, lat: ~ 2^2 } hitcount: 15 188737036435SSteven Rostedt (VMware) { pid: 2033, prio: 9, lat: ~ 2^2 } hitcount: 91 188837036435SSteven Rostedt (VMware) { pid: 2032, prio: 9, lat: ~ 2^2 } hitcount: 125 188937036435SSteven Rostedt (VMware) { pid: 2029, prio: 120, lat: ~ 2^2 } hitcount: 4 189037036435SSteven Rostedt (VMware) { pid: 2031, prio: 120, lat: ~ 2^2 } hitcount: 3 189137036435SSteven Rostedt (VMware) { pid: 2029, prio: 120, lat: ~ 2^3 } hitcount: 2 189237036435SSteven Rostedt (VMware) { pid: 2035, prio: 9, lat: ~ 2^3 } hitcount: 41 189337036435SSteven Rostedt (VMware) { pid: 2030, prio: 120, lat: ~ 2^3 } hitcount: 1 189437036435SSteven Rostedt (VMware) { pid: 2032, prio: 9, lat: ~ 2^3 } hitcount: 32 189537036435SSteven Rostedt (VMware) { pid: 2031, prio: 9, lat: ~ 2^3 } hitcount: 44 189637036435SSteven Rostedt (VMware) { pid: 2034, prio: 9, lat: ~ 2^3 } hitcount: 40 189737036435SSteven Rostedt (VMware) { pid: 2030, prio: 9, lat: ~ 2^3 } hitcount: 29 189837036435SSteven Rostedt (VMware) { pid: 2033, prio: 9, lat: ~ 2^3 } hitcount: 31 189937036435SSteven Rostedt (VMware) { pid: 2029, prio: 9, lat: ~ 2^3 } hitcount: 31 190037036435SSteven Rostedt (VMware) { pid: 2028, prio: 120, lat: ~ 2^3 } hitcount: 18 190137036435SSteven Rostedt (VMware) { pid: 2031, prio: 120, lat: ~ 2^3 } hitcount: 2 190237036435SSteven Rostedt (VMware) { pid: 2028, prio: 120, lat: ~ 2^4 } hitcount: 1 190337036435SSteven Rostedt (VMware) { pid: 2029, prio: 9, lat: ~ 2^4 } hitcount: 4 190437036435SSteven Rostedt (VMware) { pid: 2031, prio: 120, lat: ~ 2^7 } hitcount: 1 190537036435SSteven Rostedt (VMware) { pid: 2032, prio: 120, lat: ~ 2^7 } hitcount: 1 190637036435SSteven Rostedt (VMware) 190737036435SSteven Rostedt (VMware) Totals: 190837036435SSteven Rostedt (VMware) Hits: 2122 190937036435SSteven Rostedt (VMware) Entries: 30 191037036435SSteven Rostedt (VMware) Dropped: 0 191137036435SSteven Rostedt (VMware) 191237036435SSteven Rostedt (VMware) 191337036435SSteven Rostedt (VMware)The latency values can also be grouped linearly by a given size with 1914a2ff84a5SBagas Sanjayathe ".buckets" modifier and specify a size (in this case groups of 10):: 191537036435SSteven Rostedt (VMware) 191637036435SSteven Rostedt (VMware) # echo 'hist:keys=pid,prio,lat.buckets=10:sort=lat' >> \ 19172abfcd29SRoss Zwisler /sys/kernel/tracing/events/synthetic/wakeup_latency/trigger 191837036435SSteven Rostedt (VMware) 191937036435SSteven Rostedt (VMware) # event histogram 192037036435SSteven Rostedt (VMware) # 192137036435SSteven Rostedt (VMware) # trigger info: hist:keys=pid,prio,lat.buckets=10:vals=hitcount:sort=lat.buckets=10:size=2048 [active] 192237036435SSteven Rostedt (VMware) # 192337036435SSteven Rostedt (VMware) 192437036435SSteven Rostedt (VMware) { pid: 2067, prio: 9, lat: ~ 0-9 } hitcount: 220 192537036435SSteven Rostedt (VMware) { pid: 2068, prio: 9, lat: ~ 0-9 } hitcount: 157 192637036435SSteven Rostedt (VMware) { pid: 2070, prio: 9, lat: ~ 0-9 } hitcount: 100 192737036435SSteven Rostedt (VMware) { pid: 2067, prio: 120, lat: ~ 0-9 } hitcount: 6 192837036435SSteven Rostedt (VMware) { pid: 2065, prio: 120, lat: ~ 0-9 } hitcount: 2 192937036435SSteven Rostedt (VMware) { pid: 2066, prio: 120, lat: ~ 0-9 } hitcount: 2 193037036435SSteven Rostedt (VMware) { pid: 2069, prio: 9, lat: ~ 0-9 } hitcount: 122 193137036435SSteven Rostedt (VMware) { pid: 2069, prio: 120, lat: ~ 0-9 } hitcount: 8 193237036435SSteven Rostedt (VMware) { pid: 2070, prio: 120, lat: ~ 0-9 } hitcount: 1 193337036435SSteven Rostedt (VMware) { pid: 2068, prio: 120, lat: ~ 0-9 } hitcount: 7 193437036435SSteven Rostedt (VMware) { pid: 2066, prio: 9, lat: ~ 0-9 } hitcount: 365 193537036435SSteven Rostedt (VMware) { pid: 2064, prio: 120, lat: ~ 0-9 } hitcount: 35 193637036435SSteven Rostedt (VMware) { pid: 2065, prio: 9, lat: ~ 0-9 } hitcount: 998 193737036435SSteven Rostedt (VMware) { pid: 2071, prio: 9, lat: ~ 0-9 } hitcount: 85 193837036435SSteven Rostedt (VMware) { pid: 2065, prio: 9, lat: ~ 10-19 } hitcount: 2 193937036435SSteven Rostedt (VMware) { pid: 2064, prio: 120, lat: ~ 10-19 } hitcount: 2 194037036435SSteven Rostedt (VMware) 194137036435SSteven Rostedt (VMware) Totals: 194237036435SSteven Rostedt (VMware) Hits: 2112 194337036435SSteven Rostedt (VMware) Entries: 16 194437036435SSteven Rostedt (VMware) Dropped: 0 194537036435SSteven Rostedt (VMware) 194688238513SSteven Rostedt (Google)To save stacktraces, create a synthetic event with a field of type "unsigned long[]" 194788238513SSteven Rostedt (Google)or even just "long[]". For example, to see how long a task is blocked in an 1948a2ff84a5SBagas Sanjayauninterruptible state:: 194988238513SSteven Rostedt (Google) 195088238513SSteven Rostedt (Google) # cd /sys/kernel/tracing 195188238513SSteven Rostedt (Google) # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events 1952*4b512860SSteven Rostedt (Google) # echo 'hist:keys=next_pid:ts=common_timestamp.usecs,st=common_stacktrace if prev_state == 2' >> events/sched/sched_switch/trigger 195388238513SSteven Rostedt (Google) # echo 'hist:keys=prev_pid:delta=common_timestamp.usecs-$ts,s=$st:onmax($delta).trace(block_lat,prev_pid,$delta,$s)' >> events/sched/sched_switch/trigger 195488238513SSteven Rostedt (Google) # echo 1 > events/synthetic/block_lat/enable 195588238513SSteven Rostedt (Google) # cat trace 195688238513SSteven Rostedt (Google) 195788238513SSteven Rostedt (Google) # tracer: nop 195888238513SSteven Rostedt (Google) # 195988238513SSteven Rostedt (Google) # entries-in-buffer/entries-written: 2/2 #P:8 196088238513SSteven Rostedt (Google) # 196188238513SSteven Rostedt (Google) # _-----=> irqs-off/BH-disabled 196288238513SSteven Rostedt (Google) # / _----=> need-resched 196388238513SSteven Rostedt (Google) # | / _---=> hardirq/softirq 196488238513SSteven Rostedt (Google) # || / _--=> preempt-depth 196588238513SSteven Rostedt (Google) # ||| / _-=> migrate-disable 196688238513SSteven Rostedt (Google) # |||| / delay 196788238513SSteven Rostedt (Google) # TASK-PID CPU# ||||| TIMESTAMP FUNCTION 196888238513SSteven Rostedt (Google) # | | | ||||| | | 196988238513SSteven Rostedt (Google) <idle>-0 [005] d..4. 521.164922: block_lat: pid=0 delta=8322 stack=STACK: 197088238513SSteven Rostedt (Google) => __schedule+0x448/0x7b0 197188238513SSteven Rostedt (Google) => schedule+0x5a/0xb0 197288238513SSteven Rostedt (Google) => io_schedule+0x42/0x70 197388238513SSteven Rostedt (Google) => bit_wait_io+0xd/0x60 197488238513SSteven Rostedt (Google) => __wait_on_bit+0x4b/0x140 197588238513SSteven Rostedt (Google) => out_of_line_wait_on_bit+0x91/0xb0 197688238513SSteven Rostedt (Google) => jbd2_journal_commit_transaction+0x1679/0x1a70 197788238513SSteven Rostedt (Google) => kjournald2+0xa9/0x280 197888238513SSteven Rostedt (Google) => kthread+0xe9/0x110 197988238513SSteven Rostedt (Google) => ret_from_fork+0x2c/0x50 198088238513SSteven Rostedt (Google) 198188238513SSteven Rostedt (Google) <...>-2 [004] d..4. 525.184257: block_lat: pid=2 delta=76 stack=STACK: 198288238513SSteven Rostedt (Google) => __schedule+0x448/0x7b0 198388238513SSteven Rostedt (Google) => schedule+0x5a/0xb0 198488238513SSteven Rostedt (Google) => schedule_timeout+0x11a/0x150 198588238513SSteven Rostedt (Google) => wait_for_completion_killable+0x144/0x1f0 198688238513SSteven Rostedt (Google) => __kthread_create_on_node+0xe7/0x1e0 198788238513SSteven Rostedt (Google) => kthread_create_on_node+0x51/0x70 198888238513SSteven Rostedt (Google) => create_worker+0xcc/0x1a0 198988238513SSteven Rostedt (Google) => worker_thread+0x2ad/0x380 199088238513SSteven Rostedt (Google) => kthread+0xe9/0x110 199188238513SSteven Rostedt (Google) => ret_from_fork+0x2c/0x50 199288238513SSteven Rostedt (Google) 1993a2ff84a5SBagas SanjayaA synthetic event that has a stacktrace field may use it as a key in 1994a2ff84a5SBagas Sanjayahistogram:: 199588238513SSteven Rostedt (Google) 1996d8f0ae3eSTom Zanussi # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger 199788238513SSteven Rostedt (Google) # cat events/synthetic/block_lat/hist 199888238513SSteven Rostedt (Google) 199988238513SSteven Rostedt (Google) # event histogram 200088238513SSteven Rostedt (Google) # 2001d8f0ae3eSTom Zanussi # trigger info: hist:keys=delta.buckets=100,stack.stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active] 200288238513SSteven Rostedt (Google) # 2003d8f0ae3eSTom Zanussi { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520 2004d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2005d8f0ae3eSTom Zanussi io_schedule+0x46/0x80 2006d8f0ae3eSTom Zanussi bit_wait_io+0x11/0x80 2007d8f0ae3eSTom Zanussi __wait_on_bit+0x4e/0x120 2008d8f0ae3eSTom Zanussi out_of_line_wait_on_bit+0x8d/0xb0 2009d8f0ae3eSTom Zanussi __wait_on_buffer+0x33/0x40 2010d8f0ae3eSTom Zanussi jbd2_journal_commit_transaction+0x155a/0x19b0 2011d8f0ae3eSTom Zanussi kjournald2+0xab/0x270 2012d8f0ae3eSTom Zanussi kthread+0xfa/0x130 2013d8f0ae3eSTom Zanussi ret_from_fork+0x29/0x50 201488238513SSteven Rostedt (Google) } hitcount: 1 2015d8f0ae3eSTom Zanussi { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520 2016d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2017d8f0ae3eSTom Zanussi io_schedule+0x46/0x80 2018d8f0ae3eSTom Zanussi rq_qos_wait+0xd0/0x170 2019d8f0ae3eSTom Zanussi wbt_wait+0x9e/0xf0 2020d8f0ae3eSTom Zanussi __rq_qos_throttle+0x25/0x40 2021d8f0ae3eSTom Zanussi blk_mq_submit_bio+0x2c3/0x5b0 2022d8f0ae3eSTom Zanussi __submit_bio+0xff/0x190 2023d8f0ae3eSTom Zanussi submit_bio_noacct_nocheck+0x25b/0x2b0 2024d8f0ae3eSTom Zanussi submit_bio_noacct+0x20b/0x600 2025d8f0ae3eSTom Zanussi submit_bio+0x28/0x90 2026d8f0ae3eSTom Zanussi ext4_bio_write_page+0x1e0/0x8c0 2027d8f0ae3eSTom Zanussi mpage_submit_page+0x60/0x80 2028d8f0ae3eSTom Zanussi mpage_process_page_bufs+0x16c/0x180 2029d8f0ae3eSTom Zanussi mpage_prepare_extent_to_map+0x23f/0x530 2030d8f0ae3eSTom Zanussi } hitcount: 1 2031d8f0ae3eSTom Zanussi { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520 2032d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2033d8f0ae3eSTom Zanussi schedule_hrtimeout_range_clock+0x97/0x110 2034d8f0ae3eSTom Zanussi schedule_hrtimeout_range+0x13/0x20 2035d8f0ae3eSTom Zanussi usleep_range_state+0x65/0x90 2036d8f0ae3eSTom Zanussi __intel_wait_for_register+0x1c1/0x230 [i915] 2037d8f0ae3eSTom Zanussi intel_psr_wait_for_idle_locked+0x171/0x2a0 [i915] 2038d8f0ae3eSTom Zanussi intel_pipe_update_start+0x169/0x360 [i915] 2039d8f0ae3eSTom Zanussi intel_update_crtc+0x112/0x490 [i915] 2040d8f0ae3eSTom Zanussi skl_commit_modeset_enables+0x199/0x600 [i915] 2041d8f0ae3eSTom Zanussi intel_atomic_commit_tail+0x7c4/0x1080 [i915] 2042d8f0ae3eSTom Zanussi intel_atomic_commit_work+0x12/0x20 [i915] 2043d8f0ae3eSTom Zanussi process_one_work+0x21c/0x3f0 2044d8f0ae3eSTom Zanussi worker_thread+0x50/0x3e0 2045d8f0ae3eSTom Zanussi kthread+0xfa/0x130 2046d8f0ae3eSTom Zanussi } hitcount: 3 2047d8f0ae3eSTom Zanussi { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520 2048d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2049d8f0ae3eSTom Zanussi schedule_timeout+0x11e/0x160 2050d8f0ae3eSTom Zanussi __wait_for_common+0x8f/0x190 2051d8f0ae3eSTom Zanussi wait_for_completion+0x24/0x30 2052d8f0ae3eSTom Zanussi __flush_work.isra.0+0x1cc/0x360 2053d8f0ae3eSTom Zanussi flush_work+0xe/0x20 2054d8f0ae3eSTom Zanussi drm_mode_rmfb+0x18b/0x1d0 [drm] 2055d8f0ae3eSTom Zanussi drm_mode_rmfb_ioctl+0x10/0x20 [drm] 2056d8f0ae3eSTom Zanussi drm_ioctl_kernel+0xb8/0x150 [drm] 2057d8f0ae3eSTom Zanussi drm_ioctl+0x243/0x560 [drm] 2058d8f0ae3eSTom Zanussi __x64_sys_ioctl+0x92/0xd0 2059d8f0ae3eSTom Zanussi do_syscall_64+0x59/0x90 2060d8f0ae3eSTom Zanussi entry_SYSCALL_64_after_hwframe+0x72/0xdc 2061d8f0ae3eSTom Zanussi } hitcount: 1 2062d8f0ae3eSTom Zanussi { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520 2063d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2064d8f0ae3eSTom Zanussi schedule_timeout+0x87/0x160 2065d8f0ae3eSTom Zanussi __wait_for_common+0x8f/0x190 2066d8f0ae3eSTom Zanussi wait_for_completion_timeout+0x1d/0x30 2067d8f0ae3eSTom Zanussi drm_atomic_helper_wait_for_flip_done+0x57/0x90 [drm_kms_helper] 2068d8f0ae3eSTom Zanussi intel_atomic_commit_tail+0x8ce/0x1080 [i915] 2069d8f0ae3eSTom Zanussi intel_atomic_commit_work+0x12/0x20 [i915] 2070d8f0ae3eSTom Zanussi process_one_work+0x21c/0x3f0 2071d8f0ae3eSTom Zanussi worker_thread+0x50/0x3e0 2072d8f0ae3eSTom Zanussi kthread+0xfa/0x130 2073d8f0ae3eSTom Zanussi ret_from_fork+0x29/0x50 2074d8f0ae3eSTom Zanussi } hitcount: 1 2075d8f0ae3eSTom Zanussi { delta: ~ 100-199, stack.stacktrace __schedule+0xa19/0x1520 2076d8f0ae3eSTom Zanussi schedule+0x6b/0x110 2077d8f0ae3eSTom Zanussi schedule_hrtimeout_range_clock+0x97/0x110 2078d8f0ae3eSTom Zanussi schedule_hrtimeout_range+0x13/0x20 2079d8f0ae3eSTom Zanussi usleep_range_state+0x65/0x90 2080d8f0ae3eSTom Zanussi pci_set_low_power_state+0x17f/0x1f0 2081d8f0ae3eSTom Zanussi pci_set_power_state+0x49/0x250 2082d8f0ae3eSTom Zanussi pci_finish_runtime_suspend+0x4a/0x90 2083d8f0ae3eSTom Zanussi pci_pm_runtime_suspend+0xcb/0x1b0 2084d8f0ae3eSTom Zanussi __rpm_callback+0x48/0x120 2085d8f0ae3eSTom Zanussi rpm_callback+0x67/0x70 2086d8f0ae3eSTom Zanussi rpm_suspend+0x167/0x780 2087d8f0ae3eSTom Zanussi rpm_idle+0x25a/0x380 2088d8f0ae3eSTom Zanussi pm_runtime_work+0x93/0xc0 2089d8f0ae3eSTom Zanussi process_one_work+0x21c/0x3f0 209088238513SSteven Rostedt (Google) } hitcount: 1 209188238513SSteven Rostedt (Google) 209288238513SSteven Rostedt (Google) Totals: 2093d8f0ae3eSTom Zanussi Hits: 10 2094d8f0ae3eSTom Zanussi Entries: 7 209588238513SSteven Rostedt (Google) Dropped: 0 209688238513SSteven Rostedt (Google) 20975032b381STom Zanussi2.2.3 Hist trigger 'handlers' and 'actions' 20985032b381STom Zanussi------------------------------------------- 2099ea272257SMauro Carvalho Chehab 21005032b381STom ZanussiA hist trigger 'action' is a function that's executed (in most cases 21015032b381STom Zanussiconditionally) whenever a histogram entry is added or updated. 2102ea272257SMauro Carvalho Chehab 21035032b381STom ZanussiWhen a histogram entry is added or updated, a hist trigger 'handler' 21045032b381STom Zanussiis what decides whether the corresponding action is actually invoked 21055032b381STom Zanussior not. 2106ea272257SMauro Carvalho Chehab 21075032b381STom ZanussiHist trigger handlers and actions are paired together in the general 21085032b381STom Zanussiform: 21095032b381STom Zanussi 21105032b381STom Zanussi <handler>.<action> 21115032b381STom Zanussi 21125032b381STom ZanussiTo specify a handler.action pair for a given event, simply specify 21135032b381STom Zanussithat handler.action pair between colons in the hist trigger 21145032b381STom Zanussispecification. 21155032b381STom Zanussi 21165032b381STom ZanussiIn theory, any handler can be combined with any action, but in 21175032b381STom Zanussipractice, not every handler.action combination is currently supported; 21185032b381STom Zanussiif a given handler.action combination isn't supported, the hist 21195032b381STom Zanussitrigger will fail with -EINVAL; 21205032b381STom Zanussi 2121fe4ec72cSMasanari IidaThe default 'handler.action' if none is explicitly specified is as it 21225032b381STom Zanussialways has been, to simply update the set of values associated with an 21235032b381STom Zanussientry. Some applications, however, may want to perform additional 21245032b381STom Zanussiactions at that point, such as generate another event, or compare and 21255032b381STom Zanussisave a maximum. 21265032b381STom Zanussi 21275032b381STom ZanussiThe supported handlers and actions are listed below, and each is 21285032b381STom Zanussidescribed in more detail in the following paragraphs, in the context 21295032b381STom Zanussiof descriptions of some common and useful handler.action combinations. 21305032b381STom Zanussi 21315032b381STom ZanussiThe available handlers are: 21325032b381STom Zanussi 21335032b381STom Zanussi - onmatch(matching.event) - invoke action on any addition or update 21345032b381STom Zanussi - onmax(var) - invoke action if var exceeds current max 2135ff0d35e2STom Zanussi - onchange(var) - invoke action if var changes 21365032b381STom Zanussi 21375032b381STom ZanussiThe available actions are: 21385032b381STom Zanussi 2139e91eefd7STom Zanussi - trace(<synthetic_event_name>,param list) - generate synthetic event 21405032b381STom Zanussi - save(field,...) - save current event fields 2141fd451a3dSTom Zanussi - snapshot() - snapshot the trace buffer 21425032b381STom Zanussi 21435032b381STom ZanussiThe following commonly-used handler.action pairs are available: 2144ea272257SMauro Carvalho Chehab 2145e91eefd7STom Zanussi - onmatch(matching.event).trace(<synthetic_event_name>,param list) 2146ea272257SMauro Carvalho Chehab 2147e91eefd7STom Zanussi The 'onmatch(matching.event).trace(<synthetic_event_name>,param 2148e91eefd7STom Zanussi list)' hist trigger action is invoked whenever an event matches 2149e91eefd7STom Zanussi and the histogram entry would be added or updated. It causes the 2150e91eefd7STom Zanussi named synthetic event to be generated with the values given in the 2151ea272257SMauro Carvalho Chehab 'param list'. The result is the generation of a synthetic event 2152ea272257SMauro Carvalho Chehab that consists of the values contained in those variables at the 2153e91eefd7STom Zanussi time the invoking event was hit. For example, if the synthetic 2154e91eefd7STom Zanussi event name is 'wakeup_latency', a wakeup_latency event is 2155e91eefd7STom Zanussi generated using onmatch(event).trace(wakeup_latency,arg1,arg2). 2156ea272257SMauro Carvalho Chehab 2157e91eefd7STom Zanussi There is also an equivalent alternative form available for 2158e91eefd7STom Zanussi generating synthetic events. In this form, the synthetic event 2159e91eefd7STom Zanussi name is used as if it were a function name. For example, using 2160e91eefd7STom Zanussi the 'wakeup_latency' synthetic event name again, the 2161e91eefd7STom Zanussi wakeup_latency event would be generated by invoking it as if it 2162e91eefd7STom Zanussi were a function call, with the event field values passed in as 2163e91eefd7STom Zanussi arguments: onmatch(event).wakeup_latency(arg1,arg2). The syntax 2164e91eefd7STom Zanussi for this form is: 2165e91eefd7STom Zanussi 2166e91eefd7STom Zanussi onmatch(matching.event).<synthetic_event_name>(param list) 2167e91eefd7STom Zanussi 2168e91eefd7STom Zanussi In either case, the 'param list' consists of one or more 2169e91eefd7STom Zanussi parameters which may be either variables or fields defined on 2170e91eefd7STom Zanussi either the 'matching.event' or the target event. The variables or 2171e91eefd7STom Zanussi fields specified in the param list may be either fully-qualified 2172e91eefd7STom Zanussi or unqualified. If a variable is specified as unqualified, it 2173e91eefd7STom Zanussi must be unique between the two events. A field name used as a 2174e91eefd7STom Zanussi param can be unqualified if it refers to the target event, but 2175e91eefd7STom Zanussi must be fully qualified if it refers to the matching event. A 2176e91eefd7STom Zanussi fully-qualified name is of the form 'system.event_name.$var_name' 2177e91eefd7STom Zanussi or 'system.event_name.field'. 2178ea272257SMauro Carvalho Chehab 2179ea272257SMauro Carvalho Chehab The 'matching.event' specification is simply the fully qualified 2180ea272257SMauro Carvalho Chehab event name of the event that matches the target event for the 218139a39d5bSTzvetomir Stoyanov onmatch() functionality, in the form 'system.event_name'. Histogram 218239a39d5bSTzvetomir Stoyanov keys of both events are compared to find if events match. In case 218339a39d5bSTzvetomir Stoyanov multiple histogram keys are used, they all must match in the specified 218439a39d5bSTzvetomir Stoyanov order. 2185ea272257SMauro Carvalho Chehab 2186ea272257SMauro Carvalho Chehab Finally, the number and type of variables/fields in the 'param 2187ea272257SMauro Carvalho Chehab list' must match the number and types of the fields in the 2188ea272257SMauro Carvalho Chehab synthetic event being generated. 2189ea272257SMauro Carvalho Chehab 2190ea272257SMauro Carvalho Chehab As an example the below defines a simple synthetic event and uses 2191ea272257SMauro Carvalho Chehab a variable defined on the sched_wakeup_new event as a parameter 2192ea272257SMauro Carvalho Chehab when invoking the synthetic event. Here we define the synthetic 2193ea272257SMauro Carvalho Chehab event:: 2194ea272257SMauro Carvalho Chehab 2195ea272257SMauro Carvalho Chehab # echo 'wakeup_new_test pid_t pid' >> \ 21962abfcd29SRoss Zwisler /sys/kernel/tracing/synthetic_events 2197ea272257SMauro Carvalho Chehab 21982abfcd29SRoss Zwisler # cat /sys/kernel/tracing/synthetic_events 2199ea272257SMauro Carvalho Chehab wakeup_new_test pid_t pid 2200ea272257SMauro Carvalho Chehab 2201ea272257SMauro Carvalho Chehab The following hist trigger both defines the missing testpid 2202ea272257SMauro Carvalho Chehab variable and specifies an onmatch() action that generates a 2203ea272257SMauro Carvalho Chehab wakeup_new_test synthetic event whenever a sched_wakeup_new event 2204ea272257SMauro Carvalho Chehab occurs, which because of the 'if comm == "cyclictest"' filter only 2205ea272257SMauro Carvalho Chehab happens when the executable is cyclictest:: 2206ea272257SMauro Carvalho Chehab 2207ea272257SMauro Carvalho Chehab # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\ 2208ea272257SMauro Carvalho Chehab wakeup_new_test($testpid) if comm=="cyclictest"' >> \ 22092abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_wakeup_new/trigger 2210ea272257SMauro Carvalho Chehab 2211a2ff84a5SBagas Sanjaya Or, equivalently, using the 'trace' keyword syntax:: 2212e91eefd7STom Zanussi 2213e91eefd7STom Zanussi # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\ 2214e91eefd7STom Zanussi trace(wakeup_new_test,$testpid) if comm=="cyclictest"' >> \ 22152abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_wakeup_new/trigger 2216e91eefd7STom Zanussi 2217ea272257SMauro Carvalho Chehab Creating and displaying a histogram based on those events is now 2218ea272257SMauro Carvalho Chehab just a matter of using the fields and new synthetic event in the 2219ea272257SMauro Carvalho Chehab tracing/events/synthetic directory, as usual:: 2220ea272257SMauro Carvalho Chehab 2221ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:sort=pid' >> \ 22222abfcd29SRoss Zwisler /sys/kernel/tracing/events/synthetic/wakeup_new_test/trigger 2223ea272257SMauro Carvalho Chehab 2224ea272257SMauro Carvalho Chehab Running 'cyclictest' should cause wakeup_new events to generate 2225ea272257SMauro Carvalho Chehab wakeup_new_test synthetic events which should result in histogram 2226ea272257SMauro Carvalho Chehab output in the wakeup_new_test event's hist file:: 2227ea272257SMauro Carvalho Chehab 22282abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/synthetic/wakeup_new_test/hist 2229ea272257SMauro Carvalho Chehab 2230ea272257SMauro Carvalho Chehab A more typical usage would be to use two events to calculate a 2231ea272257SMauro Carvalho Chehab latency. The following example uses a set of hist triggers to 2232ea272257SMauro Carvalho Chehab produce a 'wakeup_latency' histogram. 2233ea272257SMauro Carvalho Chehab 2234ea272257SMauro Carvalho Chehab First, we define a 'wakeup_latency' synthetic event:: 2235ea272257SMauro Carvalho Chehab 2236ea272257SMauro Carvalho Chehab # echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \ 22372abfcd29SRoss Zwisler /sys/kernel/tracing/synthetic_events 2238ea272257SMauro Carvalho Chehab 2239ea272257SMauro Carvalho Chehab Next, we specify that whenever we see a sched_waking event for a 2240ea272257SMauro Carvalho Chehab cyclictest thread, save the timestamp in a 'ts0' variable:: 2241ea272257SMauro Carvalho Chehab 2242ea272257SMauro Carvalho Chehab # echo 'hist:keys=$saved_pid:saved_pid=pid:ts0=common_timestamp.usecs \ 2243ea272257SMauro Carvalho Chehab if comm=="cyclictest"' >> \ 22442abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_waking/trigger 2245ea272257SMauro Carvalho Chehab 2246ea272257SMauro Carvalho Chehab Then, when the corresponding thread is actually scheduled onto the 224739a39d5bSTzvetomir Stoyanov CPU by a sched_switch event (saved_pid matches next_pid), calculate 224839a39d5bSTzvetomir Stoyanov the latency and use that along with another variable and an event field 224939a39d5bSTzvetomir Stoyanov to generate a wakeup_latency synthetic event:: 2250ea272257SMauro Carvalho Chehab 2251ea272257SMauro Carvalho Chehab # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:\ 2252ea272257SMauro Carvalho Chehab onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,\ 2253ea272257SMauro Carvalho Chehab $saved_pid,next_prio) if next_comm=="cyclictest"' >> \ 22542abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_switch/trigger 2255ea272257SMauro Carvalho Chehab 2256ea272257SMauro Carvalho Chehab We also need to create a histogram on the wakeup_latency synthetic 2257ea272257SMauro Carvalho Chehab event in order to aggregate the generated synthetic event data:: 2258ea272257SMauro Carvalho Chehab 2259ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid,prio,lat:sort=pid,lat' >> \ 22602abfcd29SRoss Zwisler /sys/kernel/tracing/events/synthetic/wakeup_latency/trigger 2261ea272257SMauro Carvalho Chehab 2262ea272257SMauro Carvalho Chehab Finally, once we've run cyclictest to actually generate some 2263ea272257SMauro Carvalho Chehab events, we can see the output by looking at the wakeup_latency 2264ea272257SMauro Carvalho Chehab synthetic event's hist file:: 2265ea272257SMauro Carvalho Chehab 22662abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/synthetic/wakeup_latency/hist 2267ea272257SMauro Carvalho Chehab 2268ea272257SMauro Carvalho Chehab - onmax(var).save(field,.. .) 2269ea272257SMauro Carvalho Chehab 2270ea272257SMauro Carvalho Chehab The 'onmax(var).save(field,...)' hist trigger action is invoked 2271ea272257SMauro Carvalho Chehab whenever the value of 'var' associated with a histogram entry 2272ea272257SMauro Carvalho Chehab exceeds the current maximum contained in that variable. 2273ea272257SMauro Carvalho Chehab 2274ea272257SMauro Carvalho Chehab The end result is that the trace event fields specified as the 2275ea272257SMauro Carvalho Chehab onmax.save() params will be saved if 'var' exceeds the current 2276ea272257SMauro Carvalho Chehab maximum for that hist trigger entry. This allows context from the 2277ea272257SMauro Carvalho Chehab event that exhibited the new maximum to be saved for later 2278ea272257SMauro Carvalho Chehab reference. When the histogram is displayed, additional fields 2279ea272257SMauro Carvalho Chehab displaying the saved values will be printed. 2280ea272257SMauro Carvalho Chehab 2281ea272257SMauro Carvalho Chehab As an example the below defines a couple of hist triggers, one for 2282ea272257SMauro Carvalho Chehab sched_waking and another for sched_switch, keyed on pid. Whenever 2283ea272257SMauro Carvalho Chehab a sched_waking occurs, the timestamp is saved in the entry 2284ea272257SMauro Carvalho Chehab corresponding to the current pid, and when the scheduler switches 2285ea272257SMauro Carvalho Chehab back to that pid, the timestamp difference is calculated. If the 2286ea272257SMauro Carvalho Chehab resulting latency, stored in wakeup_lat, exceeds the current 2287ea272257SMauro Carvalho Chehab maximum latency, the values specified in the save() fields are 2288ea272257SMauro Carvalho Chehab recorded:: 2289ea272257SMauro Carvalho Chehab 2290ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:ts0=common_timestamp.usecs \ 2291ea272257SMauro Carvalho Chehab if comm=="cyclictest"' >> \ 22922abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_waking/trigger 2293ea272257SMauro Carvalho Chehab 2294ea272257SMauro Carvalho Chehab # echo 'hist:keys=next_pid:\ 2295ea272257SMauro Carvalho Chehab wakeup_lat=common_timestamp.usecs-$ts0:\ 2296ea272257SMauro Carvalho Chehab onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \ 2297ea272257SMauro Carvalho Chehab if next_comm=="cyclictest"' >> \ 22982abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_switch/trigger 2299ea272257SMauro Carvalho Chehab 2300ea272257SMauro Carvalho Chehab When the histogram is displayed, the max value and the saved 2301ea272257SMauro Carvalho Chehab values corresponding to the max are displayed following the rest 2302ea272257SMauro Carvalho Chehab of the fields:: 2303ea272257SMauro Carvalho Chehab 23042abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_switch/hist 2305ea272257SMauro Carvalho Chehab { next_pid: 2255 } hitcount: 239 2306ea272257SMauro Carvalho Chehab common_timestamp-ts0: 0 2307ea272257SMauro Carvalho Chehab max: 27 2308ea272257SMauro Carvalho Chehab next_comm: cyclictest 2309ea272257SMauro Carvalho Chehab prev_pid: 0 prev_prio: 120 prev_comm: swapper/1 2310ea272257SMauro Carvalho Chehab 2311ea272257SMauro Carvalho Chehab { next_pid: 2256 } hitcount: 2355 2312ea272257SMauro Carvalho Chehab common_timestamp-ts0: 0 2313ea272257SMauro Carvalho Chehab max: 49 next_comm: cyclictest 2314ea272257SMauro Carvalho Chehab prev_pid: 0 prev_prio: 120 prev_comm: swapper/0 2315ea272257SMauro Carvalho Chehab 2316ea272257SMauro Carvalho Chehab Totals: 2317ea272257SMauro Carvalho Chehab Hits: 12970 2318ea272257SMauro Carvalho Chehab Entries: 2 2319ea272257SMauro Carvalho Chehab Dropped: 0 2320ea272257SMauro Carvalho Chehab 2321fd451a3dSTom Zanussi - onmax(var).snapshot() 2322fd451a3dSTom Zanussi 2323fd451a3dSTom Zanussi The 'onmax(var).snapshot()' hist trigger action is invoked 2324fd451a3dSTom Zanussi whenever the value of 'var' associated with a histogram entry 2325fd451a3dSTom Zanussi exceeds the current maximum contained in that variable. 2326fd451a3dSTom Zanussi 2327fd451a3dSTom Zanussi The end result is that a global snapshot of the trace buffer will 2328fd451a3dSTom Zanussi be saved in the tracing/snapshot file if 'var' exceeds the current 2329fd451a3dSTom Zanussi maximum for any hist trigger entry. 2330fd451a3dSTom Zanussi 2331fd451a3dSTom Zanussi Note that in this case the maximum is a global maximum for the 2332fd451a3dSTom Zanussi current trace instance, which is the maximum across all buckets of 2333fd451a3dSTom Zanussi the histogram. The key of the specific trace event that caused 2334fd451a3dSTom Zanussi the global maximum and the global maximum itself are displayed, 2335fd451a3dSTom Zanussi along with a message stating that a snapshot has been taken and 2336fd451a3dSTom Zanussi where to find it. The user can use the key information displayed 2337fd451a3dSTom Zanussi to locate the corresponding bucket in the histogram for even more 2338fd451a3dSTom Zanussi detail. 2339fd451a3dSTom Zanussi 2340fd451a3dSTom Zanussi As an example the below defines a couple of hist triggers, one for 2341fd451a3dSTom Zanussi sched_waking and another for sched_switch, keyed on pid. Whenever 2342fd451a3dSTom Zanussi a sched_waking event occurs, the timestamp is saved in the entry 2343fd451a3dSTom Zanussi corresponding to the current pid, and when the scheduler switches 2344fd451a3dSTom Zanussi back to that pid, the timestamp difference is calculated. If the 2345fd451a3dSTom Zanussi resulting latency, stored in wakeup_lat, exceeds the current 2346fd451a3dSTom Zanussi maximum latency, a snapshot is taken. As part of the setup, all 2347fd451a3dSTom Zanussi the scheduler events are also enabled, which are the events that 2348a2ff84a5SBagas Sanjaya will show up in the snapshot when it is taken at some point:: 2349fd451a3dSTom Zanussi 23502abfcd29SRoss Zwisler # echo 1 > /sys/kernel/tracing/events/sched/enable 2351fd451a3dSTom Zanussi 2352fd451a3dSTom Zanussi # echo 'hist:keys=pid:ts0=common_timestamp.usecs \ 2353fd451a3dSTom Zanussi if comm=="cyclictest"' >> \ 23542abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_waking/trigger 2355fd451a3dSTom Zanussi 2356fd451a3dSTom Zanussi # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0: \ 2357fd451a3dSTom Zanussi onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio, \ 2358fd451a3dSTom Zanussi prev_comm):onmax($wakeup_lat).snapshot() \ 2359fd451a3dSTom Zanussi if next_comm=="cyclictest"' >> \ 23602abfcd29SRoss Zwisler /sys/kernel/tracing/events/sched/sched_switch/trigger 2361fd451a3dSTom Zanussi 2362fd451a3dSTom Zanussi When the histogram is displayed, for each bucket the max value 2363fd451a3dSTom Zanussi and the saved values corresponding to the max are displayed 2364fd451a3dSTom Zanussi following the rest of the fields. 2365fd451a3dSTom Zanussi 2366fe4ec72cSMasanari Iida If a snapshot was taken, there is also a message indicating that, 2367a2ff84a5SBagas Sanjaya along with the value and event that triggered the global maximum:: 2368fd451a3dSTom Zanussi 23692abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/sched/sched_switch/hist 2370fd451a3dSTom Zanussi { next_pid: 2101 } hitcount: 200 2371fd451a3dSTom Zanussi max: 52 next_prio: 120 next_comm: cyclictest \ 2372fd451a3dSTom Zanussi prev_pid: 0 prev_prio: 120 prev_comm: swapper/6 2373fd451a3dSTom Zanussi 2374fd451a3dSTom Zanussi { next_pid: 2103 } hitcount: 1326 2375fd451a3dSTom Zanussi max: 572 next_prio: 19 next_comm: cyclictest \ 2376fd451a3dSTom Zanussi prev_pid: 0 prev_prio: 120 prev_comm: swapper/1 2377fd451a3dSTom Zanussi 2378fd451a3dSTom Zanussi { next_pid: 2102 } hitcount: 1982 \ 2379fd451a3dSTom Zanussi max: 74 next_prio: 19 next_comm: cyclictest \ 2380fd451a3dSTom Zanussi prev_pid: 0 prev_prio: 120 prev_comm: swapper/5 2381fd451a3dSTom Zanussi 2382fd451a3dSTom Zanussi Snapshot taken (see tracing/snapshot). Details: 2383fd451a3dSTom Zanussi triggering value { onmax($wakeup_lat) }: 572 \ 2384fd451a3dSTom Zanussi triggered by event with key: { next_pid: 2103 } 2385fd451a3dSTom Zanussi 2386fd451a3dSTom Zanussi Totals: 2387fd451a3dSTom Zanussi Hits: 3508 2388fd451a3dSTom Zanussi Entries: 3 2389fd451a3dSTom Zanussi Dropped: 0 2390fd451a3dSTom Zanussi 2391fd451a3dSTom Zanussi In the above case, the event that triggered the global maximum has 2392fd451a3dSTom Zanussi the key with next_pid == 2103. If you look at the bucket that has 2393fd451a3dSTom Zanussi 2103 as the key, you'll find the additional values save()'d along 2394fd451a3dSTom Zanussi with the local maximum for that bucket, which should be the same 2395fd451a3dSTom Zanussi as the global maximum (since that was the same value that 2396fd451a3dSTom Zanussi triggered the global snapshot). 2397fd451a3dSTom Zanussi 2398fd451a3dSTom Zanussi And finally, looking at the snapshot data should show at or near 2399fd451a3dSTom Zanussi the end the event that triggered the snapshot (in this case you 2400fd451a3dSTom Zanussi can verify the timestamps between the sched_waking and 2401fd451a3dSTom Zanussi sched_switch events, which should match the time displayed in the 24023df5ffd2SMauro Carvalho Chehab global maximum):: 2403fd451a3dSTom Zanussi 24042abfcd29SRoss Zwisler # cat /sys/kernel/tracing/snapshot 2405fd451a3dSTom Zanussi 2406fd451a3dSTom Zanussi <...>-2103 [005] d..3 309.873125: sched_switch: prev_comm=cyclictest prev_pid=2103 prev_prio=19 prev_state=D ==> next_comm=swapper/5 next_pid=0 next_prio=120 2407fd451a3dSTom Zanussi <idle>-0 [005] d.h3 309.873611: sched_waking: comm=cyclictest pid=2102 prio=19 target_cpu=005 2408fd451a3dSTom Zanussi <idle>-0 [005] dNh4 309.873613: sched_wakeup: comm=cyclictest pid=2102 prio=19 target_cpu=005 2409fd451a3dSTom Zanussi <idle>-0 [005] d..3 309.873616: sched_switch: prev_comm=swapper/5 prev_pid=0 prev_prio=120 prev_state=S ==> next_comm=cyclictest next_pid=2102 next_prio=19 2410fd451a3dSTom Zanussi <...>-2102 [005] d..3 309.873625: sched_switch: prev_comm=cyclictest prev_pid=2102 prev_prio=19 prev_state=D ==> next_comm=swapper/5 next_pid=0 next_prio=120 2411fd451a3dSTom Zanussi <idle>-0 [005] d.h3 309.874624: sched_waking: comm=cyclictest pid=2102 prio=19 target_cpu=005 2412fd451a3dSTom Zanussi <idle>-0 [005] dNh4 309.874626: sched_wakeup: comm=cyclictest pid=2102 prio=19 target_cpu=005 2413fd451a3dSTom Zanussi <idle>-0 [005] dNh3 309.874628: sched_waking: comm=cyclictest pid=2103 prio=19 target_cpu=005 2414fd451a3dSTom Zanussi <idle>-0 [005] dNh4 309.874630: sched_wakeup: comm=cyclictest pid=2103 prio=19 target_cpu=005 2415fd451a3dSTom Zanussi <idle>-0 [005] d..3 309.874633: sched_switch: prev_comm=swapper/5 prev_pid=0 prev_prio=120 prev_state=S ==> next_comm=cyclictest next_pid=2102 next_prio=19 2416fd451a3dSTom Zanussi <idle>-0 [004] d.h3 309.874757: sched_waking: comm=gnome-terminal- pid=1699 prio=120 target_cpu=004 2417fd451a3dSTom Zanussi <idle>-0 [004] dNh4 309.874762: sched_wakeup: comm=gnome-terminal- pid=1699 prio=120 target_cpu=004 2418fd451a3dSTom Zanussi <idle>-0 [004] d..3 309.874766: sched_switch: prev_comm=swapper/4 prev_pid=0 prev_prio=120 prev_state=S ==> next_comm=gnome-terminal- next_pid=1699 next_prio=120 2419fd451a3dSTom Zanussi gnome-terminal--1699 [004] d.h2 309.874941: sched_stat_runtime: comm=gnome-terminal- pid=1699 runtime=180706 [ns] vruntime=1126870572 [ns] 2420fd451a3dSTom Zanussi <idle>-0 [003] d.s4 309.874956: sched_waking: comm=rcu_sched pid=9 prio=120 target_cpu=007 2421fd451a3dSTom Zanussi <idle>-0 [003] d.s5 309.874960: sched_wake_idle_without_ipi: cpu=7 2422fd451a3dSTom Zanussi <idle>-0 [003] d.s5 309.874961: sched_wakeup: comm=rcu_sched pid=9 prio=120 target_cpu=007 2423fd451a3dSTom Zanussi <idle>-0 [007] d..3 309.874963: sched_switch: prev_comm=swapper/7 prev_pid=0 prev_prio=120 prev_state=S ==> next_comm=rcu_sched next_pid=9 next_prio=120 2424fd451a3dSTom Zanussi rcu_sched-9 [007] d..3 309.874973: sched_stat_runtime: comm=rcu_sched pid=9 runtime=13646 [ns] vruntime=22531430286 [ns] 2425fd451a3dSTom Zanussi rcu_sched-9 [007] d..3 309.874978: sched_switch: prev_comm=rcu_sched prev_pid=9 prev_prio=120 prev_state=R+ ==> next_comm=swapper/7 next_pid=0 next_prio=120 2426fd451a3dSTom Zanussi <...>-2102 [005] d..4 309.874994: sched_migrate_task: comm=cyclictest pid=2103 prio=19 orig_cpu=5 dest_cpu=1 2427fd451a3dSTom Zanussi <...>-2102 [005] d..4 309.875185: sched_wake_idle_without_ipi: cpu=1 2428fd451a3dSTom Zanussi <idle>-0 [001] d..3 309.875200: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=S ==> next_comm=cyclictest next_pid=2103 next_prio=19 2429fd451a3dSTom Zanussi 2430ff0d35e2STom Zanussi - onchange(var).save(field,.. .) 2431ff0d35e2STom Zanussi 2432ff0d35e2STom Zanussi The 'onchange(var).save(field,...)' hist trigger action is invoked 2433ff0d35e2STom Zanussi whenever the value of 'var' associated with a histogram entry 2434ff0d35e2STom Zanussi changes. 2435ff0d35e2STom Zanussi 2436ff0d35e2STom Zanussi The end result is that the trace event fields specified as the 2437ff0d35e2STom Zanussi onchange.save() params will be saved if 'var' changes for that 2438ff0d35e2STom Zanussi hist trigger entry. This allows context from the event that 2439ff0d35e2STom Zanussi changed the value to be saved for later reference. When the 2440ff0d35e2STom Zanussi histogram is displayed, additional fields displaying the saved 2441ff0d35e2STom Zanussi values will be printed. 2442ff0d35e2STom Zanussi 2443ff0d35e2STom Zanussi - onchange(var).snapshot() 2444ff0d35e2STom Zanussi 2445ff0d35e2STom Zanussi The 'onchange(var).snapshot()' hist trigger action is invoked 2446ff0d35e2STom Zanussi whenever the value of 'var' associated with a histogram entry 2447ff0d35e2STom Zanussi changes. 2448ff0d35e2STom Zanussi 2449ff0d35e2STom Zanussi The end result is that a global snapshot of the trace buffer will 2450ff0d35e2STom Zanussi be saved in the tracing/snapshot file if 'var' changes for any 2451ff0d35e2STom Zanussi hist trigger entry. 2452ff0d35e2STom Zanussi 2453ff0d35e2STom Zanussi Note that in this case the changed value is a global variable 2454fe4ec72cSMasanari Iida associated with current trace instance. The key of the specific 2455ff0d35e2STom Zanussi trace event that caused the value to change and the global value 2456ff0d35e2STom Zanussi itself are displayed, along with a message stating that a snapshot 2457ff0d35e2STom Zanussi has been taken and where to find it. The user can use the key 2458ff0d35e2STom Zanussi information displayed to locate the corresponding bucket in the 2459ff0d35e2STom Zanussi histogram for even more detail. 2460ff0d35e2STom Zanussi 2461ff0d35e2STom Zanussi As an example the below defines a hist trigger on the tcp_probe 2462ff0d35e2STom Zanussi event, keyed on dport. Whenever a tcp_probe event occurs, the 2463ff0d35e2STom Zanussi cwnd field is checked against the current value stored in the 2464ff0d35e2STom Zanussi $cwnd variable. If the value has changed, a snapshot is taken. 2465ff0d35e2STom Zanussi As part of the setup, all the scheduler and tcp events are also 2466ff0d35e2STom Zanussi enabled, which are the events that will show up in the snapshot 2467a2ff84a5SBagas Sanjaya when it is taken at some point:: 2468ff0d35e2STom Zanussi 24692abfcd29SRoss Zwisler # echo 1 > /sys/kernel/tracing/events/sched/enable 24702abfcd29SRoss Zwisler # echo 1 > /sys/kernel/tracing/events/tcp/enable 2471ff0d35e2STom Zanussi 2472ff0d35e2STom Zanussi # echo 'hist:keys=dport:cwnd=snd_cwnd: \ 2473ff0d35e2STom Zanussi onchange($cwnd).save(snd_wnd,srtt,rcv_wnd): \ 2474ff0d35e2STom Zanussi onchange($cwnd).snapshot()' >> \ 24752abfcd29SRoss Zwisler /sys/kernel/tracing/events/tcp/tcp_probe/trigger 2476ff0d35e2STom Zanussi 2477ff0d35e2STom Zanussi When the histogram is displayed, for each bucket the tracked value 2478ff0d35e2STom Zanussi and the saved values corresponding to that value are displayed 2479ff0d35e2STom Zanussi following the rest of the fields. 2480ff0d35e2STom Zanussi 2481fe4ec72cSMasanari Iida If a snapshot was taken, there is also a message indicating that, 24823df5ffd2SMauro Carvalho Chehab along with the value and event that triggered the snapshot:: 2483ff0d35e2STom Zanussi 24842abfcd29SRoss Zwisler # cat /sys/kernel/tracing/events/tcp/tcp_probe/hist 24853df5ffd2SMauro Carvalho Chehab 2486ff0d35e2STom Zanussi { dport: 1521 } hitcount: 8 2487ff0d35e2STom Zanussi changed: 10 snd_wnd: 35456 srtt: 154262 rcv_wnd: 42112 2488ff0d35e2STom Zanussi 2489ff0d35e2STom Zanussi { dport: 80 } hitcount: 23 2490ff0d35e2STom Zanussi changed: 10 snd_wnd: 28960 srtt: 19604 rcv_wnd: 29312 2491ff0d35e2STom Zanussi 2492ff0d35e2STom Zanussi { dport: 9001 } hitcount: 172 2493ff0d35e2STom Zanussi changed: 10 snd_wnd: 48384 srtt: 260444 rcv_wnd: 55168 2494ff0d35e2STom Zanussi 2495ff0d35e2STom Zanussi { dport: 443 } hitcount: 211 2496ff0d35e2STom Zanussi changed: 10 snd_wnd: 26960 srtt: 17379 rcv_wnd: 28800 2497ff0d35e2STom Zanussi 2498a2ff84a5SBagas Sanjaya Snapshot taken (see tracing/snapshot). Details: 24993df5ffd2SMauro Carvalho Chehab 2500ff0d35e2STom Zanussi triggering value { onchange($cwnd) }: 10 2501ff0d35e2STom Zanussi triggered by event with key: { dport: 80 } 2502ff0d35e2STom Zanussi 2503ff0d35e2STom Zanussi Totals: 2504ff0d35e2STom Zanussi Hits: 414 2505ff0d35e2STom Zanussi Entries: 4 2506ff0d35e2STom Zanussi Dropped: 0 2507ff0d35e2STom Zanussi 2508ff0d35e2STom Zanussi In the above case, the event that triggered the snapshot has the 2509ff0d35e2STom Zanussi key with dport == 80. If you look at the bucket that has 80 as 2510ff0d35e2STom Zanussi the key, you'll find the additional values save()'d along with the 2511ff0d35e2STom Zanussi changed value for that bucket, which should be the same as the 2512ff0d35e2STom Zanussi global changed value (since that was the same value that triggered 2513ff0d35e2STom Zanussi the global snapshot). 2514ff0d35e2STom Zanussi 2515ff0d35e2STom Zanussi And finally, looking at the snapshot data should show at or near 25163df5ffd2SMauro Carvalho Chehab the end the event that triggered the snapshot:: 2517ff0d35e2STom Zanussi 25182abfcd29SRoss Zwisler # cat /sys/kernel/tracing/snapshot 2519ff0d35e2STom Zanussi 2520ff0d35e2STom Zanussi gnome-shell-1261 [006] dN.3 49.823113: sched_stat_runtime: comm=gnome-shell pid=1261 runtime=49347 [ns] vruntime=1835730389 [ns] 2521ff0d35e2STom Zanussi kworker/u16:4-773 [003] d..3 49.823114: sched_switch: prev_comm=kworker/u16:4 prev_pid=773 prev_prio=120 prev_state=R+ ==> next_comm=kworker/3:2 next_pid=135 next_prio=120 2522ff0d35e2STom Zanussi gnome-shell-1261 [006] d..3 49.823114: sched_switch: prev_comm=gnome-shell prev_pid=1261 prev_prio=120 prev_state=R+ ==> next_comm=kworker/6:2 next_pid=387 next_prio=120 2523ff0d35e2STom Zanussi kworker/3:2-135 [003] d..3 49.823118: sched_stat_runtime: comm=kworker/3:2 pid=135 runtime=5339 [ns] vruntime=17815800388 [ns] 2524ff0d35e2STom Zanussi kworker/6:2-387 [006] d..3 49.823120: sched_stat_runtime: comm=kworker/6:2 pid=387 runtime=9594 [ns] vruntime=14589605367 [ns] 2525ff0d35e2STom Zanussi kworker/6:2-387 [006] d..3 49.823122: sched_switch: prev_comm=kworker/6:2 prev_pid=387 prev_prio=120 prev_state=R+ ==> next_comm=gnome-shell next_pid=1261 next_prio=120 2526ff0d35e2STom Zanussi kworker/3:2-135 [003] d..3 49.823123: sched_switch: prev_comm=kworker/3:2 prev_pid=135 prev_prio=120 prev_state=T ==> next_comm=swapper/3 next_pid=0 next_prio=120 2527ff0d35e2STom Zanussi <idle>-0 [004] ..s7 49.823798: tcp_probe: src=10.0.0.10:54326 dest=23.215.104.193:80 mark=0x0 length=32 snd_nxt=0xe3ae2ff5 snd_una=0xe3ae2ecd snd_cwnd=10 ssthresh=2147483647 snd_wnd=28960 srtt=19604 rcv_wnd=29312 2528ff0d35e2STom Zanussi 2529ea272257SMauro Carvalho Chehab3. User space creating a trigger 2530ea272257SMauro Carvalho Chehab-------------------------------- 2531ea272257SMauro Carvalho Chehab 2532ea272257SMauro Carvalho ChehabWriting into /sys/kernel/tracing/trace_marker writes into the ftrace 2533ea272257SMauro Carvalho Chehabring buffer. This can also act like an event, by writing into the trigger 2534ea272257SMauro Carvalho Chehabfile located in /sys/kernel/tracing/events/ftrace/print/ 2535ea272257SMauro Carvalho Chehab 2536ea272257SMauro Carvalho ChehabModifying cyclictest to write into the trace_marker file before it sleeps 2537ea272257SMauro Carvalho Chehaband after it wakes up, something like this:: 2538ea272257SMauro Carvalho Chehab 2539ea272257SMauro Carvalho Chehab static void traceputs(char *str) 2540ea272257SMauro Carvalho Chehab { 2541ea272257SMauro Carvalho Chehab /* tracemark_fd is the trace_marker file descriptor */ 2542ea272257SMauro Carvalho Chehab if (tracemark_fd < 0) 2543ea272257SMauro Carvalho Chehab return; 2544ea272257SMauro Carvalho Chehab /* write the tracemark message */ 2545ea272257SMauro Carvalho Chehab write(tracemark_fd, str, strlen(str)); 2546ea272257SMauro Carvalho Chehab } 2547ea272257SMauro Carvalho Chehab 2548ea272257SMauro Carvalho ChehabAnd later add something like:: 2549ea272257SMauro Carvalho Chehab 2550ea272257SMauro Carvalho Chehab traceputs("start"); 2551ea272257SMauro Carvalho Chehab clock_nanosleep(...); 2552ea272257SMauro Carvalho Chehab traceputs("end"); 2553ea272257SMauro Carvalho Chehab 2554ea272257SMauro Carvalho ChehabWe can make a histogram from this:: 2555ea272257SMauro Carvalho Chehab 2556ea272257SMauro Carvalho Chehab # cd /sys/kernel/tracing 2557ea272257SMauro Carvalho Chehab # echo 'latency u64 lat' > synthetic_events 2558ea272257SMauro Carvalho Chehab # echo 'hist:keys=common_pid:ts0=common_timestamp.usecs if buf == "start"' > events/ftrace/print/trigger 2559ea272257SMauro Carvalho Chehab # echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(ftrace.print).latency($lat) if buf == "end"' >> events/ftrace/print/trigger 2560ea272257SMauro Carvalho Chehab # echo 'hist:keys=lat,common_pid:sort=lat' > events/synthetic/latency/trigger 2561ea272257SMauro Carvalho Chehab 2562ea272257SMauro Carvalho ChehabThe above created a synthetic event called "latency" and two histograms 2563ea272257SMauro Carvalho Chehabagainst the trace_marker, one gets triggered when "start" is written into the 2564ea272257SMauro Carvalho Chehabtrace_marker file and the other when "end" is written. If the pids match, then 2565ea272257SMauro Carvalho Chehabit will call the "latency" synthetic event with the calculated latency as its 2566ea272257SMauro Carvalho Chehabparameter. Finally, a histogram is added to the latency synthetic event to 2567ea272257SMauro Carvalho Chehabrecord the calculated latency along with the pid. 2568ea272257SMauro Carvalho Chehab 2569ea272257SMauro Carvalho ChehabNow running cyclictest with:: 2570ea272257SMauro Carvalho Chehab 2571ea272257SMauro Carvalho Chehab # ./cyclictest -p80 -d0 -i250 -n -a -t --tracemark -b 1000 2572ea272257SMauro Carvalho Chehab 2573ea272257SMauro Carvalho Chehab -p80 : run threads at priority 80 2574ea272257SMauro Carvalho Chehab -d0 : have all threads run at the same interval 2575ea272257SMauro Carvalho Chehab -i250 : start the interval at 250 microseconds (all threads will do this) 2576ea272257SMauro Carvalho Chehab -n : sleep with nanosleep 2577ea272257SMauro Carvalho Chehab -a : affine all threads to a separate CPU 2578ea272257SMauro Carvalho Chehab -t : one thread per available CPU 2579ea272257SMauro Carvalho Chehab --tracemark : enable trace mark writing 2580ea272257SMauro Carvalho Chehab -b 1000 : stop if any latency is greater than 1000 microseconds 2581ea272257SMauro Carvalho Chehab 2582ea272257SMauro Carvalho ChehabNote, the -b 1000 is used just to make --tracemark available. 2583ea272257SMauro Carvalho Chehab 2584ea272257SMauro Carvalho ChehabThen we can see the histogram created by this with:: 2585ea272257SMauro Carvalho Chehab 2586ea272257SMauro Carvalho Chehab # cat events/synthetic/latency/hist 2587ea272257SMauro Carvalho Chehab # event histogram 2588ea272257SMauro Carvalho Chehab # 2589ea272257SMauro Carvalho Chehab # trigger info: hist:keys=lat,common_pid:vals=hitcount:sort=lat:size=2048 [active] 2590ea272257SMauro Carvalho Chehab # 2591ea272257SMauro Carvalho Chehab 2592ea272257SMauro Carvalho Chehab { lat: 107, common_pid: 2039 } hitcount: 1 2593ea272257SMauro Carvalho Chehab { lat: 122, common_pid: 2041 } hitcount: 1 2594ea272257SMauro Carvalho Chehab { lat: 166, common_pid: 2039 } hitcount: 1 2595ea272257SMauro Carvalho Chehab { lat: 174, common_pid: 2039 } hitcount: 1 2596ea272257SMauro Carvalho Chehab { lat: 194, common_pid: 2041 } hitcount: 1 2597ea272257SMauro Carvalho Chehab { lat: 196, common_pid: 2036 } hitcount: 1 2598ea272257SMauro Carvalho Chehab { lat: 197, common_pid: 2038 } hitcount: 1 2599ea272257SMauro Carvalho Chehab { lat: 198, common_pid: 2039 } hitcount: 1 2600ea272257SMauro Carvalho Chehab { lat: 199, common_pid: 2039 } hitcount: 1 2601ea272257SMauro Carvalho Chehab { lat: 200, common_pid: 2041 } hitcount: 1 2602ea272257SMauro Carvalho Chehab { lat: 201, common_pid: 2039 } hitcount: 2 2603ea272257SMauro Carvalho Chehab { lat: 202, common_pid: 2038 } hitcount: 1 2604ea272257SMauro Carvalho Chehab { lat: 202, common_pid: 2043 } hitcount: 1 2605ea272257SMauro Carvalho Chehab { lat: 203, common_pid: 2039 } hitcount: 1 2606ea272257SMauro Carvalho Chehab { lat: 203, common_pid: 2036 } hitcount: 1 2607ea272257SMauro Carvalho Chehab { lat: 203, common_pid: 2041 } hitcount: 1 2608ea272257SMauro Carvalho Chehab { lat: 206, common_pid: 2038 } hitcount: 2 2609ea272257SMauro Carvalho Chehab { lat: 207, common_pid: 2039 } hitcount: 1 2610ea272257SMauro Carvalho Chehab { lat: 207, common_pid: 2036 } hitcount: 1 2611ea272257SMauro Carvalho Chehab { lat: 208, common_pid: 2040 } hitcount: 1 2612ea272257SMauro Carvalho Chehab { lat: 209, common_pid: 2043 } hitcount: 1 2613ea272257SMauro Carvalho Chehab { lat: 210, common_pid: 2039 } hitcount: 1 2614ea272257SMauro Carvalho Chehab { lat: 211, common_pid: 2039 } hitcount: 4 2615ea272257SMauro Carvalho Chehab { lat: 212, common_pid: 2043 } hitcount: 1 2616ea272257SMauro Carvalho Chehab { lat: 212, common_pid: 2039 } hitcount: 2 2617ea272257SMauro Carvalho Chehab { lat: 213, common_pid: 2039 } hitcount: 1 2618ea272257SMauro Carvalho Chehab { lat: 214, common_pid: 2038 } hitcount: 1 2619ea272257SMauro Carvalho Chehab { lat: 214, common_pid: 2039 } hitcount: 2 2620ea272257SMauro Carvalho Chehab { lat: 214, common_pid: 2042 } hitcount: 1 2621ea272257SMauro Carvalho Chehab { lat: 215, common_pid: 2039 } hitcount: 1 2622ea272257SMauro Carvalho Chehab { lat: 217, common_pid: 2036 } hitcount: 1 2623ea272257SMauro Carvalho Chehab { lat: 217, common_pid: 2040 } hitcount: 1 2624ea272257SMauro Carvalho Chehab { lat: 217, common_pid: 2039 } hitcount: 1 2625ea272257SMauro Carvalho Chehab { lat: 218, common_pid: 2039 } hitcount: 6 2626ea272257SMauro Carvalho Chehab { lat: 219, common_pid: 2039 } hitcount: 9 2627ea272257SMauro Carvalho Chehab { lat: 220, common_pid: 2039 } hitcount: 11 2628ea272257SMauro Carvalho Chehab { lat: 221, common_pid: 2039 } hitcount: 5 2629ea272257SMauro Carvalho Chehab { lat: 221, common_pid: 2042 } hitcount: 1 2630ea272257SMauro Carvalho Chehab { lat: 222, common_pid: 2039 } hitcount: 7 2631ea272257SMauro Carvalho Chehab { lat: 223, common_pid: 2036 } hitcount: 1 2632ea272257SMauro Carvalho Chehab { lat: 223, common_pid: 2039 } hitcount: 3 2633ea272257SMauro Carvalho Chehab { lat: 224, common_pid: 2039 } hitcount: 4 2634ea272257SMauro Carvalho Chehab { lat: 224, common_pid: 2037 } hitcount: 1 2635ea272257SMauro Carvalho Chehab { lat: 224, common_pid: 2036 } hitcount: 2 2636ea272257SMauro Carvalho Chehab { lat: 225, common_pid: 2039 } hitcount: 5 2637ea272257SMauro Carvalho Chehab { lat: 225, common_pid: 2042 } hitcount: 1 2638ea272257SMauro Carvalho Chehab { lat: 226, common_pid: 2039 } hitcount: 7 2639ea272257SMauro Carvalho Chehab { lat: 226, common_pid: 2036 } hitcount: 4 2640ea272257SMauro Carvalho Chehab { lat: 227, common_pid: 2039 } hitcount: 6 2641ea272257SMauro Carvalho Chehab { lat: 227, common_pid: 2036 } hitcount: 12 2642ea272257SMauro Carvalho Chehab { lat: 227, common_pid: 2043 } hitcount: 1 2643ea272257SMauro Carvalho Chehab { lat: 228, common_pid: 2039 } hitcount: 7 2644ea272257SMauro Carvalho Chehab { lat: 228, common_pid: 2036 } hitcount: 14 2645ea272257SMauro Carvalho Chehab { lat: 229, common_pid: 2039 } hitcount: 9 2646ea272257SMauro Carvalho Chehab { lat: 229, common_pid: 2036 } hitcount: 8 2647ea272257SMauro Carvalho Chehab { lat: 229, common_pid: 2038 } hitcount: 1 2648ea272257SMauro Carvalho Chehab { lat: 230, common_pid: 2039 } hitcount: 11 2649ea272257SMauro Carvalho Chehab { lat: 230, common_pid: 2036 } hitcount: 6 2650ea272257SMauro Carvalho Chehab { lat: 230, common_pid: 2043 } hitcount: 1 2651ea272257SMauro Carvalho Chehab { lat: 230, common_pid: 2042 } hitcount: 2 2652ea272257SMauro Carvalho Chehab { lat: 231, common_pid: 2041 } hitcount: 1 2653ea272257SMauro Carvalho Chehab { lat: 231, common_pid: 2036 } hitcount: 6 2654ea272257SMauro Carvalho Chehab { lat: 231, common_pid: 2043 } hitcount: 1 2655ea272257SMauro Carvalho Chehab { lat: 231, common_pid: 2039 } hitcount: 8 2656ea272257SMauro Carvalho Chehab { lat: 232, common_pid: 2037 } hitcount: 1 2657ea272257SMauro Carvalho Chehab { lat: 232, common_pid: 2039 } hitcount: 6 2658ea272257SMauro Carvalho Chehab { lat: 232, common_pid: 2040 } hitcount: 2 2659ea272257SMauro Carvalho Chehab { lat: 232, common_pid: 2036 } hitcount: 5 2660ea272257SMauro Carvalho Chehab { lat: 232, common_pid: 2043 } hitcount: 1 2661ea272257SMauro Carvalho Chehab { lat: 233, common_pid: 2036 } hitcount: 5 2662ea272257SMauro Carvalho Chehab { lat: 233, common_pid: 2039 } hitcount: 11 2663ea272257SMauro Carvalho Chehab { lat: 234, common_pid: 2039 } hitcount: 4 2664ea272257SMauro Carvalho Chehab { lat: 234, common_pid: 2038 } hitcount: 2 2665ea272257SMauro Carvalho Chehab { lat: 234, common_pid: 2043 } hitcount: 2 2666ea272257SMauro Carvalho Chehab { lat: 234, common_pid: 2036 } hitcount: 11 2667ea272257SMauro Carvalho Chehab { lat: 234, common_pid: 2040 } hitcount: 1 2668ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2037 } hitcount: 2 2669ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2036 } hitcount: 8 2670ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2043 } hitcount: 2 2671ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2039 } hitcount: 5 2672ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2042 } hitcount: 2 2673ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2040 } hitcount: 4 2674ea272257SMauro Carvalho Chehab { lat: 235, common_pid: 2041 } hitcount: 1 2675ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2036 } hitcount: 7 2676ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2037 } hitcount: 1 2677ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2041 } hitcount: 5 2678ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2039 } hitcount: 3 2679ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2043 } hitcount: 9 2680ea272257SMauro Carvalho Chehab { lat: 236, common_pid: 2040 } hitcount: 7 2681ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2037 } hitcount: 1 2682ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2040 } hitcount: 1 2683ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2036 } hitcount: 9 2684ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2039 } hitcount: 3 2685ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2043 } hitcount: 8 2686ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2042 } hitcount: 2 2687ea272257SMauro Carvalho Chehab { lat: 237, common_pid: 2041 } hitcount: 2 2688ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2043 } hitcount: 10 2689ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2040 } hitcount: 1 2690ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2037 } hitcount: 9 2691ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2038 } hitcount: 1 2692ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2039 } hitcount: 1 2693ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2042 } hitcount: 3 2694ea272257SMauro Carvalho Chehab { lat: 238, common_pid: 2036 } hitcount: 7 2695ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2041 } hitcount: 1 2696ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2043 } hitcount: 11 2697ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2037 } hitcount: 11 2698ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2038 } hitcount: 6 2699ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2036 } hitcount: 7 2700ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2040 } hitcount: 1 2701ea272257SMauro Carvalho Chehab { lat: 239, common_pid: 2042 } hitcount: 9 2702ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2037 } hitcount: 29 2703ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2043 } hitcount: 15 2704ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2040 } hitcount: 44 2705ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2039 } hitcount: 1 2706ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2041 } hitcount: 2 2707ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2038 } hitcount: 1 2708ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2036 } hitcount: 10 2709ea272257SMauro Carvalho Chehab { lat: 240, common_pid: 2042 } hitcount: 13 2710ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2036 } hitcount: 21 2711ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2041 } hitcount: 36 2712ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2037 } hitcount: 34 2713ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2042 } hitcount: 14 2714ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2040 } hitcount: 94 2715ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2039 } hitcount: 12 2716ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2038 } hitcount: 2 2717ea272257SMauro Carvalho Chehab { lat: 241, common_pid: 2043 } hitcount: 28 2718ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2040 } hitcount: 109 2719ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2041 } hitcount: 506 2720ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2039 } hitcount: 155 2721ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2042 } hitcount: 21 2722ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2037 } hitcount: 52 2723ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2043 } hitcount: 21 2724ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2036 } hitcount: 16 2725ea272257SMauro Carvalho Chehab { lat: 242, common_pid: 2038 } hitcount: 156 2726ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2037 } hitcount: 46 2727ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2039 } hitcount: 40 2728ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2042 } hitcount: 119 2729ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2041 } hitcount: 611 2730ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2036 } hitcount: 69 2731ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2038 } hitcount: 784 2732ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2040 } hitcount: 323 2733ea272257SMauro Carvalho Chehab { lat: 243, common_pid: 2043 } hitcount: 14 2734ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2043 } hitcount: 35 2735ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2042 } hitcount: 305 2736ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2039 } hitcount: 8 2737ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2040 } hitcount: 4515 2738ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2038 } hitcount: 371 2739ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2037 } hitcount: 31 2740ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2036 } hitcount: 114 2741ea272257SMauro Carvalho Chehab { lat: 244, common_pid: 2041 } hitcount: 3396 2742ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2036 } hitcount: 700 2743ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2041 } hitcount: 2772 2744ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2037 } hitcount: 268 2745ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2039 } hitcount: 472 2746ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2038 } hitcount: 2758 2747ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2042 } hitcount: 3833 2748ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2040 } hitcount: 3105 2749ea272257SMauro Carvalho Chehab { lat: 245, common_pid: 2043 } hitcount: 645 2750ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2038 } hitcount: 3451 2751ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2041 } hitcount: 142 2752ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2037 } hitcount: 5101 2753ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2040 } hitcount: 68 2754ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2043 } hitcount: 5099 2755ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2039 } hitcount: 5608 2756ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2042 } hitcount: 3723 2757ea272257SMauro Carvalho Chehab { lat: 246, common_pid: 2036 } hitcount: 4738 2758ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2042 } hitcount: 312 2759ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2043 } hitcount: 2385 2760ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2041 } hitcount: 452 2761ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2038 } hitcount: 792 2762ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2040 } hitcount: 78 2763ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2036 } hitcount: 2375 2764ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2039 } hitcount: 1834 2765ea272257SMauro Carvalho Chehab { lat: 247, common_pid: 2037 } hitcount: 2655 2766ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2037 } hitcount: 36 2767ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2042 } hitcount: 11 2768ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2038 } hitcount: 122 2769ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2036 } hitcount: 135 2770ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2039 } hitcount: 26 2771ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2041 } hitcount: 503 2772ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2043 } hitcount: 66 2773ea272257SMauro Carvalho Chehab { lat: 248, common_pid: 2040 } hitcount: 46 2774ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2037 } hitcount: 29 2775ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2038 } hitcount: 1 2776ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2043 } hitcount: 29 2777ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2039 } hitcount: 8 2778ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2042 } hitcount: 56 2779ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2040 } hitcount: 27 2780ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2041 } hitcount: 11 2781ea272257SMauro Carvalho Chehab { lat: 249, common_pid: 2036 } hitcount: 27 2782ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2038 } hitcount: 1 2783ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2036 } hitcount: 30 2784ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2040 } hitcount: 19 2785ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2043 } hitcount: 22 2786ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2042 } hitcount: 20 2787ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2041 } hitcount: 1 2788ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2039 } hitcount: 6 2789ea272257SMauro Carvalho Chehab { lat: 250, common_pid: 2037 } hitcount: 48 2790ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2037 } hitcount: 43 2791ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2039 } hitcount: 1 2792ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2036 } hitcount: 12 2793ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2042 } hitcount: 2 2794ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2041 } hitcount: 1 2795ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2043 } hitcount: 15 2796ea272257SMauro Carvalho Chehab { lat: 251, common_pid: 2040 } hitcount: 3 2797ea272257SMauro Carvalho Chehab { lat: 252, common_pid: 2040 } hitcount: 1 2798ea272257SMauro Carvalho Chehab { lat: 252, common_pid: 2036 } hitcount: 12 2799ea272257SMauro Carvalho Chehab { lat: 252, common_pid: 2037 } hitcount: 21 2800ea272257SMauro Carvalho Chehab { lat: 252, common_pid: 2043 } hitcount: 14 2801ea272257SMauro Carvalho Chehab { lat: 253, common_pid: 2037 } hitcount: 21 2802ea272257SMauro Carvalho Chehab { lat: 253, common_pid: 2039 } hitcount: 2 2803ea272257SMauro Carvalho Chehab { lat: 253, common_pid: 2036 } hitcount: 9 2804ea272257SMauro Carvalho Chehab { lat: 253, common_pid: 2043 } hitcount: 6 2805ea272257SMauro Carvalho Chehab { lat: 253, common_pid: 2040 } hitcount: 1 2806ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2036 } hitcount: 8 2807ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2043 } hitcount: 3 2808ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2041 } hitcount: 1 2809ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2042 } hitcount: 1 2810ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2039 } hitcount: 1 2811ea272257SMauro Carvalho Chehab { lat: 254, common_pid: 2037 } hitcount: 12 2812ea272257SMauro Carvalho Chehab { lat: 255, common_pid: 2043 } hitcount: 1 2813ea272257SMauro Carvalho Chehab { lat: 255, common_pid: 2037 } hitcount: 2 2814ea272257SMauro Carvalho Chehab { lat: 255, common_pid: 2036 } hitcount: 2 2815ea272257SMauro Carvalho Chehab { lat: 255, common_pid: 2039 } hitcount: 8 2816ea272257SMauro Carvalho Chehab { lat: 256, common_pid: 2043 } hitcount: 1 2817ea272257SMauro Carvalho Chehab { lat: 256, common_pid: 2036 } hitcount: 4 2818ea272257SMauro Carvalho Chehab { lat: 256, common_pid: 2039 } hitcount: 6 2819ea272257SMauro Carvalho Chehab { lat: 257, common_pid: 2039 } hitcount: 5 2820ea272257SMauro Carvalho Chehab { lat: 257, common_pid: 2036 } hitcount: 4 2821ea272257SMauro Carvalho Chehab { lat: 258, common_pid: 2039 } hitcount: 5 2822ea272257SMauro Carvalho Chehab { lat: 258, common_pid: 2036 } hitcount: 2 2823ea272257SMauro Carvalho Chehab { lat: 259, common_pid: 2036 } hitcount: 7 2824ea272257SMauro Carvalho Chehab { lat: 259, common_pid: 2039 } hitcount: 7 2825ea272257SMauro Carvalho Chehab { lat: 260, common_pid: 2036 } hitcount: 8 2826ea272257SMauro Carvalho Chehab { lat: 260, common_pid: 2039 } hitcount: 6 2827ea272257SMauro Carvalho Chehab { lat: 261, common_pid: 2036 } hitcount: 5 2828ea272257SMauro Carvalho Chehab { lat: 261, common_pid: 2039 } hitcount: 7 2829ea272257SMauro Carvalho Chehab { lat: 262, common_pid: 2039 } hitcount: 5 2830ea272257SMauro Carvalho Chehab { lat: 262, common_pid: 2036 } hitcount: 5 2831ea272257SMauro Carvalho Chehab { lat: 263, common_pid: 2039 } hitcount: 7 2832ea272257SMauro Carvalho Chehab { lat: 263, common_pid: 2036 } hitcount: 7 2833ea272257SMauro Carvalho Chehab { lat: 264, common_pid: 2039 } hitcount: 9 2834ea272257SMauro Carvalho Chehab { lat: 264, common_pid: 2036 } hitcount: 9 2835ea272257SMauro Carvalho Chehab { lat: 265, common_pid: 2036 } hitcount: 5 2836ea272257SMauro Carvalho Chehab { lat: 265, common_pid: 2039 } hitcount: 1 2837ea272257SMauro Carvalho Chehab { lat: 266, common_pid: 2036 } hitcount: 1 2838ea272257SMauro Carvalho Chehab { lat: 266, common_pid: 2039 } hitcount: 3 2839ea272257SMauro Carvalho Chehab { lat: 267, common_pid: 2036 } hitcount: 1 2840ea272257SMauro Carvalho Chehab { lat: 267, common_pid: 2039 } hitcount: 3 2841ea272257SMauro Carvalho Chehab { lat: 268, common_pid: 2036 } hitcount: 1 2842ea272257SMauro Carvalho Chehab { lat: 268, common_pid: 2039 } hitcount: 6 2843ea272257SMauro Carvalho Chehab { lat: 269, common_pid: 2036 } hitcount: 1 2844ea272257SMauro Carvalho Chehab { lat: 269, common_pid: 2043 } hitcount: 1 2845ea272257SMauro Carvalho Chehab { lat: 269, common_pid: 2039 } hitcount: 2 2846ea272257SMauro Carvalho Chehab { lat: 270, common_pid: 2040 } hitcount: 1 2847ea272257SMauro Carvalho Chehab { lat: 270, common_pid: 2039 } hitcount: 6 2848ea272257SMauro Carvalho Chehab { lat: 271, common_pid: 2041 } hitcount: 1 2849ea272257SMauro Carvalho Chehab { lat: 271, common_pid: 2039 } hitcount: 5 2850ea272257SMauro Carvalho Chehab { lat: 272, common_pid: 2039 } hitcount: 10 2851ea272257SMauro Carvalho Chehab { lat: 273, common_pid: 2039 } hitcount: 8 2852ea272257SMauro Carvalho Chehab { lat: 274, common_pid: 2039 } hitcount: 2 2853ea272257SMauro Carvalho Chehab { lat: 275, common_pid: 2039 } hitcount: 1 2854ea272257SMauro Carvalho Chehab { lat: 276, common_pid: 2039 } hitcount: 2 2855ea272257SMauro Carvalho Chehab { lat: 276, common_pid: 2037 } hitcount: 1 2856ea272257SMauro Carvalho Chehab { lat: 276, common_pid: 2038 } hitcount: 1 2857ea272257SMauro Carvalho Chehab { lat: 277, common_pid: 2039 } hitcount: 1 2858ea272257SMauro Carvalho Chehab { lat: 277, common_pid: 2042 } hitcount: 1 2859ea272257SMauro Carvalho Chehab { lat: 278, common_pid: 2039 } hitcount: 1 2860ea272257SMauro Carvalho Chehab { lat: 279, common_pid: 2039 } hitcount: 4 2861ea272257SMauro Carvalho Chehab { lat: 279, common_pid: 2043 } hitcount: 1 2862ea272257SMauro Carvalho Chehab { lat: 280, common_pid: 2039 } hitcount: 3 2863ea272257SMauro Carvalho Chehab { lat: 283, common_pid: 2036 } hitcount: 2 2864ea272257SMauro Carvalho Chehab { lat: 284, common_pid: 2039 } hitcount: 1 2865ea272257SMauro Carvalho Chehab { lat: 284, common_pid: 2043 } hitcount: 1 2866ea272257SMauro Carvalho Chehab { lat: 288, common_pid: 2039 } hitcount: 1 2867ea272257SMauro Carvalho Chehab { lat: 289, common_pid: 2039 } hitcount: 1 2868ea272257SMauro Carvalho Chehab { lat: 300, common_pid: 2039 } hitcount: 1 2869ea272257SMauro Carvalho Chehab { lat: 384, common_pid: 2039 } hitcount: 1 2870ea272257SMauro Carvalho Chehab 2871ea272257SMauro Carvalho Chehab Totals: 2872ea272257SMauro Carvalho Chehab Hits: 67625 2873ea272257SMauro Carvalho Chehab Entries: 278 2874ea272257SMauro Carvalho Chehab Dropped: 0 2875ea272257SMauro Carvalho Chehab 2876ea272257SMauro Carvalho ChehabNote, the writes are around the sleep, so ideally they will all be of 250 2877ea272257SMauro Carvalho Chehabmicroseconds. If you are wondering how there are several that are under 2878ea272257SMauro Carvalho Chehab250 microseconds, that is because the way cyclictest works, is if one 2879ea272257SMauro Carvalho Chehabiteration comes in late, the next one will set the timer to wake up less that 2880ea272257SMauro Carvalho Chehab250. That is, if an iteration came in 50 microseconds late, the next wake up 2881ea272257SMauro Carvalho Chehabwill be at 200 microseconds. 2882ea272257SMauro Carvalho Chehab 2883ea272257SMauro Carvalho ChehabBut this could easily be done in userspace. To make this even more 2884ea272257SMauro Carvalho Chehabinteresting, we can mix the histogram between events that happened in the 2885ea272257SMauro Carvalho Chehabkernel with trace_marker:: 2886ea272257SMauro Carvalho Chehab 2887ea272257SMauro Carvalho Chehab # cd /sys/kernel/tracing 2888ea272257SMauro Carvalho Chehab # echo 'latency u64 lat' > synthetic_events 2889ea272257SMauro Carvalho Chehab # echo 'hist:keys=pid:ts0=common_timestamp.usecs' > events/sched/sched_waking/trigger 2890ea272257SMauro Carvalho Chehab # echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).latency($lat) if buf == "end"' > events/ftrace/print/trigger 2891ea272257SMauro Carvalho Chehab # echo 'hist:keys=lat,common_pid:sort=lat' > events/synthetic/latency/trigger 2892ea272257SMauro Carvalho Chehab 2893ea272257SMauro Carvalho ChehabThe difference this time is that instead of using the trace_marker to start 2894ea272257SMauro Carvalho Chehabthe latency, the sched_waking event is used, matching the common_pid for the 2895ea272257SMauro Carvalho Chehabtrace_marker write with the pid that is being woken by sched_waking. 2896ea272257SMauro Carvalho Chehab 2897ea272257SMauro Carvalho ChehabAfter running cyclictest again with the same parameters, we now have:: 2898ea272257SMauro Carvalho Chehab 2899ea272257SMauro Carvalho Chehab # cat events/synthetic/latency/hist 2900ea272257SMauro Carvalho Chehab # event histogram 2901ea272257SMauro Carvalho Chehab # 2902ea272257SMauro Carvalho Chehab # trigger info: hist:keys=lat,common_pid:vals=hitcount:sort=lat:size=2048 [active] 2903ea272257SMauro Carvalho Chehab # 2904ea272257SMauro Carvalho Chehab 2905ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2302 } hitcount: 640 2906ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2299 } hitcount: 42 2907ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2303 } hitcount: 18 2908ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2305 } hitcount: 166 2909ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2306 } hitcount: 1 2910ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2301 } hitcount: 91 2911ea272257SMauro Carvalho Chehab { lat: 7, common_pid: 2300 } hitcount: 17 2912ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2303 } hitcount: 8296 2913ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2304 } hitcount: 6864 2914ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2305 } hitcount: 9464 2915ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2301 } hitcount: 9213 2916ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2306 } hitcount: 6246 2917ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2302 } hitcount: 8797 2918ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2299 } hitcount: 8771 2919ea272257SMauro Carvalho Chehab { lat: 8, common_pid: 2300 } hitcount: 8119 2920ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2305 } hitcount: 1519 2921ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2299 } hitcount: 2346 2922ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2303 } hitcount: 2841 2923ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2301 } hitcount: 1846 2924ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2304 } hitcount: 3861 2925ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2302 } hitcount: 1210 2926ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2300 } hitcount: 2762 2927ea272257SMauro Carvalho Chehab { lat: 9, common_pid: 2306 } hitcount: 4247 2928ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2299 } hitcount: 16 2929ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2306 } hitcount: 333 2930ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2303 } hitcount: 16 2931ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2304 } hitcount: 168 2932ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2302 } hitcount: 240 2933ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2301 } hitcount: 28 2934ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2300 } hitcount: 95 2935ea272257SMauro Carvalho Chehab { lat: 10, common_pid: 2305 } hitcount: 18 2936ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2303 } hitcount: 5 2937ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2305 } hitcount: 8 2938ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2306 } hitcount: 221 2939ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2302 } hitcount: 76 2940ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2304 } hitcount: 26 2941ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2300 } hitcount: 125 2942ea272257SMauro Carvalho Chehab { lat: 11, common_pid: 2299 } hitcount: 2 2943ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2305 } hitcount: 3 2944ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2300 } hitcount: 6 2945ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2306 } hitcount: 90 2946ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2302 } hitcount: 4 2947ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2303 } hitcount: 1 2948ea272257SMauro Carvalho Chehab { lat: 12, common_pid: 2304 } hitcount: 122 2949ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2300 } hitcount: 12 2950ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2301 } hitcount: 1 2951ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2306 } hitcount: 32 2952ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2302 } hitcount: 5 2953ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2305 } hitcount: 1 2954ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2303 } hitcount: 1 2955ea272257SMauro Carvalho Chehab { lat: 13, common_pid: 2304 } hitcount: 61 2956ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2303 } hitcount: 4 2957ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2306 } hitcount: 5 2958ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2305 } hitcount: 4 2959ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2304 } hitcount: 62 2960ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2302 } hitcount: 19 2961ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2300 } hitcount: 33 2962ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2299 } hitcount: 1 2963ea272257SMauro Carvalho Chehab { lat: 14, common_pid: 2301 } hitcount: 4 2964ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2305 } hitcount: 1 2965ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2302 } hitcount: 25 2966ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2300 } hitcount: 11 2967ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2299 } hitcount: 5 2968ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2301 } hitcount: 1 2969ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2304 } hitcount: 8 2970ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2303 } hitcount: 1 2971ea272257SMauro Carvalho Chehab { lat: 15, common_pid: 2306 } hitcount: 6 2972ea272257SMauro Carvalho Chehab { lat: 16, common_pid: 2302 } hitcount: 31 2973ea272257SMauro Carvalho Chehab { lat: 16, common_pid: 2306 } hitcount: 3 2974ea272257SMauro Carvalho Chehab { lat: 16, common_pid: 2300 } hitcount: 5 2975ea272257SMauro Carvalho Chehab { lat: 17, common_pid: 2302 } hitcount: 6 2976ea272257SMauro Carvalho Chehab { lat: 17, common_pid: 2303 } hitcount: 1 2977ea272257SMauro Carvalho Chehab { lat: 18, common_pid: 2304 } hitcount: 1 2978ea272257SMauro Carvalho Chehab { lat: 18, common_pid: 2302 } hitcount: 8 2979ea272257SMauro Carvalho Chehab { lat: 18, common_pid: 2299 } hitcount: 1 2980ea272257SMauro Carvalho Chehab { lat: 18, common_pid: 2301 } hitcount: 1 2981ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2303 } hitcount: 4 2982ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2304 } hitcount: 5 2983ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2302 } hitcount: 4 2984ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2299 } hitcount: 3 2985ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2306 } hitcount: 1 2986ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2300 } hitcount: 4 2987ea272257SMauro Carvalho Chehab { lat: 19, common_pid: 2305 } hitcount: 5 2988ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2299 } hitcount: 2 2989ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2302 } hitcount: 3 2990ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2305 } hitcount: 1 2991ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2300 } hitcount: 2 2992ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2301 } hitcount: 2 2993ea272257SMauro Carvalho Chehab { lat: 20, common_pid: 2303 } hitcount: 3 2994ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2305 } hitcount: 1 2995ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2299 } hitcount: 5 2996ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2303 } hitcount: 4 2997ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2302 } hitcount: 7 2998ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2300 } hitcount: 1 2999ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2301 } hitcount: 5 3000ea272257SMauro Carvalho Chehab { lat: 21, common_pid: 2304 } hitcount: 2 3001ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2302 } hitcount: 5 3002ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2303 } hitcount: 1 3003ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2306 } hitcount: 3 3004ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2301 } hitcount: 2 3005ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2300 } hitcount: 1 3006ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2299 } hitcount: 1 3007ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2305 } hitcount: 1 3008ea272257SMauro Carvalho Chehab { lat: 22, common_pid: 2304 } hitcount: 1 3009ea272257SMauro Carvalho Chehab { lat: 23, common_pid: 2299 } hitcount: 1 3010ea272257SMauro Carvalho Chehab { lat: 23, common_pid: 2306 } hitcount: 2 3011ea272257SMauro Carvalho Chehab { lat: 23, common_pid: 2302 } hitcount: 6 3012ea272257SMauro Carvalho Chehab { lat: 24, common_pid: 2302 } hitcount: 3 3013ea272257SMauro Carvalho Chehab { lat: 24, common_pid: 2300 } hitcount: 1 3014ea272257SMauro Carvalho Chehab { lat: 24, common_pid: 2306 } hitcount: 2 3015ea272257SMauro Carvalho Chehab { lat: 24, common_pid: 2305 } hitcount: 1 3016ea272257SMauro Carvalho Chehab { lat: 24, common_pid: 2299 } hitcount: 1 3017ea272257SMauro Carvalho Chehab { lat: 25, common_pid: 2300 } hitcount: 1 3018ea272257SMauro Carvalho Chehab { lat: 25, common_pid: 2302 } hitcount: 4 3019ea272257SMauro Carvalho Chehab { lat: 26, common_pid: 2302 } hitcount: 2 3020ea272257SMauro Carvalho Chehab { lat: 27, common_pid: 2305 } hitcount: 1 3021ea272257SMauro Carvalho Chehab { lat: 27, common_pid: 2300 } hitcount: 1 3022ea272257SMauro Carvalho Chehab { lat: 27, common_pid: 2302 } hitcount: 3 3023ea272257SMauro Carvalho Chehab { lat: 28, common_pid: 2306 } hitcount: 1 3024ea272257SMauro Carvalho Chehab { lat: 28, common_pid: 2302 } hitcount: 4 3025ea272257SMauro Carvalho Chehab { lat: 29, common_pid: 2302 } hitcount: 1 3026ea272257SMauro Carvalho Chehab { lat: 29, common_pid: 2300 } hitcount: 2 3027ea272257SMauro Carvalho Chehab { lat: 29, common_pid: 2306 } hitcount: 1 3028ea272257SMauro Carvalho Chehab { lat: 29, common_pid: 2304 } hitcount: 1 3029ea272257SMauro Carvalho Chehab { lat: 30, common_pid: 2302 } hitcount: 4 3030ea272257SMauro Carvalho Chehab { lat: 31, common_pid: 2302 } hitcount: 6 3031ea272257SMauro Carvalho Chehab { lat: 32, common_pid: 2302 } hitcount: 1 3032ea272257SMauro Carvalho Chehab { lat: 33, common_pid: 2299 } hitcount: 1 3033ea272257SMauro Carvalho Chehab { lat: 33, common_pid: 2302 } hitcount: 3 3034ea272257SMauro Carvalho Chehab { lat: 34, common_pid: 2302 } hitcount: 2 3035ea272257SMauro Carvalho Chehab { lat: 35, common_pid: 2302 } hitcount: 1 3036ea272257SMauro Carvalho Chehab { lat: 35, common_pid: 2304 } hitcount: 1 3037ea272257SMauro Carvalho Chehab { lat: 36, common_pid: 2302 } hitcount: 4 3038ea272257SMauro Carvalho Chehab { lat: 37, common_pid: 2302 } hitcount: 6 3039ea272257SMauro Carvalho Chehab { lat: 38, common_pid: 2302 } hitcount: 2 3040ea272257SMauro Carvalho Chehab { lat: 39, common_pid: 2302 } hitcount: 2 3041ea272257SMauro Carvalho Chehab { lat: 39, common_pid: 2304 } hitcount: 1 3042ea272257SMauro Carvalho Chehab { lat: 40, common_pid: 2304 } hitcount: 2 3043ea272257SMauro Carvalho Chehab { lat: 40, common_pid: 2302 } hitcount: 5 3044ea272257SMauro Carvalho Chehab { lat: 41, common_pid: 2304 } hitcount: 1 3045ea272257SMauro Carvalho Chehab { lat: 41, common_pid: 2302 } hitcount: 8 3046ea272257SMauro Carvalho Chehab { lat: 42, common_pid: 2302 } hitcount: 6 3047ea272257SMauro Carvalho Chehab { lat: 42, common_pid: 2304 } hitcount: 1 3048ea272257SMauro Carvalho Chehab { lat: 43, common_pid: 2302 } hitcount: 3 3049ea272257SMauro Carvalho Chehab { lat: 43, common_pid: 2304 } hitcount: 4 3050ea272257SMauro Carvalho Chehab { lat: 44, common_pid: 2302 } hitcount: 6 3051ea272257SMauro Carvalho Chehab { lat: 45, common_pid: 2302 } hitcount: 5 3052ea272257SMauro Carvalho Chehab { lat: 46, common_pid: 2302 } hitcount: 5 3053ea272257SMauro Carvalho Chehab { lat: 47, common_pid: 2302 } hitcount: 7 3054ea272257SMauro Carvalho Chehab { lat: 48, common_pid: 2301 } hitcount: 1 3055ea272257SMauro Carvalho Chehab { lat: 48, common_pid: 2302 } hitcount: 9 3056ea272257SMauro Carvalho Chehab { lat: 49, common_pid: 2302 } hitcount: 3 3057ea272257SMauro Carvalho Chehab { lat: 50, common_pid: 2302 } hitcount: 1 3058ea272257SMauro Carvalho Chehab { lat: 50, common_pid: 2301 } hitcount: 1 3059ea272257SMauro Carvalho Chehab { lat: 51, common_pid: 2302 } hitcount: 2 3060ea272257SMauro Carvalho Chehab { lat: 51, common_pid: 2301 } hitcount: 1 3061ea272257SMauro Carvalho Chehab { lat: 61, common_pid: 2302 } hitcount: 1 3062ea272257SMauro Carvalho Chehab { lat: 110, common_pid: 2302 } hitcount: 1 3063ea272257SMauro Carvalho Chehab 3064ea272257SMauro Carvalho Chehab Totals: 3065ea272257SMauro Carvalho Chehab Hits: 89565 3066ea272257SMauro Carvalho Chehab Entries: 158 3067ea272257SMauro Carvalho Chehab Dropped: 0 3068ea272257SMauro Carvalho Chehab 3069ea272257SMauro Carvalho ChehabThis doesn't tell us any information about how late cyclictest may have 3070ea272257SMauro Carvalho Chehabwoken up, but it does show us a nice histogram of how long it took from 3071ea272257SMauro Carvalho Chehabthe time that cyclictest was woken to the time it made it into user space. 3072