1perf-kvm(1) 2=========== 3 4NAME 5---- 6perf-kvm - Tool to trace/measure kvm guest os 7 8SYNOPSIS 9-------- 10[verse] 11'perf kvm' [--host] [--guest] [--guestmount=<path> 12 [--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]] 13 {top|record|report|diff|buildid-list} [<options>] 14'perf kvm' [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path> 15 | --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>] 16'perf kvm stat [record|report|live] [<options>] 17 18DESCRIPTION 19----------- 20There are a couple of variants of perf kvm: 21 22 'perf kvm [options] top <command>' to generates and displays 23 a performance counter profile of guest os in realtime 24 of an arbitrary workload. 25 26 'perf kvm record <command>' to record the performance counter profile 27 of an arbitrary workload and save it into a perf data file. We set the 28 default behavior of perf kvm as --guest, so if neither --host nor --guest 29 is input, the perf data file name is perf.data.guest. If --host is input, 30 the perf data file name is perf.data.kvm. If you want to record data into 31 perf.data.host, please input --host --no-guest. The behaviors are shown as 32 following: 33 Default('') -> perf.data.guest 34 --host -> perf.data.kvm 35 --guest -> perf.data.guest 36 --host --guest -> perf.data.kvm 37 --host --no-guest -> perf.data.host 38 39 'perf kvm report' to display the performance counter profile information 40 recorded via perf kvm record. 41 42 'perf kvm diff' to displays the performance difference amongst two perf.data 43 files captured via perf record. 44 45 'perf kvm buildid-list' to display the buildids found in a perf data file, 46 so that other tools can be used to fetch packages with matching symbol tables 47 for use by perf report. As buildid is read from /sys/kernel/notes in os, then 48 if you want to list the buildid for guest, please make sure your perf data file 49 was captured with --guestmount in perf kvm record. 50 51 'perf kvm stat <command>' to run a command and gather performance counter 52 statistics. 53 Especially, perf 'kvm stat record/report' generates a statistical analysis 54 of KVM events. Currently, vmexit, mmio (x86 only) and ioport (x86 only) 55 events are supported. 'perf kvm stat record <command>' records kvm events 56 and the events between start and end <command>. 57 And this command produces a file which contains tracing results of kvm 58 events. 59 60 'perf kvm stat report' reports statistical data which includes events 61 handled time, samples, and so on. 62 63 'perf kvm stat live' reports statistical data in a live mode (similar to 64 record + report but with statistical data updated live at a given display 65 rate). 66 67OPTIONS 68------- 69-i:: 70--input=<path>:: 71 Input file name, for the 'report', 'diff' and 'buildid-list' subcommands. 72-o:: 73--output=<path>:: 74 Output file name, for the 'record' subcommand. Doesn't work with 'report', 75 just redirect the output to a file when using 'report'. 76--host:: 77 Collect host side performance profile. 78--guest:: 79 Collect guest side performance profile. 80--guestmount=<path>:: 81 Guest os root file system mount directory. Users mounts guest os 82 root directories under <path> by a specific filesystem access method, 83 typically, sshfs. For example, start 2 guest os. The one's pid is 8888 84 and the other's is 9999. 85 #mkdir ~/guestmount; cd ~/guestmount 86 #sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/ 87 #sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/ 88 #perf kvm --host --guest --guestmount=~/guestmount top 89--guestkallsyms=<path>:: 90 Guest os /proc/kallsyms file copy. 'perf' kvm' reads it to get guest 91 kernel symbols. Users copy it out from guest os. 92--guestmodules=<path>:: 93 Guest os /proc/modules file copy. 'perf' kvm' reads it to get guest 94 kernel module information. Users copy it out from guest os. 95--guestvmlinux=<path>:: 96 Guest os kernel vmlinux. 97--guest-code:: 98 Indicate that guest code can be found in the hypervisor process, 99 which is a common case for KVM test programs. 100-v:: 101--verbose:: 102 Be more verbose (show counter open errors, etc). 103 104STAT REPORT OPTIONS 105------------------- 106--vcpu=<value>:: 107 analyze events which occur on this vcpu. (default: all vcpus) 108 109--event=<value>:: 110 event to be analyzed. Possible values: vmexit, mmio (x86 only), 111 ioport (x86 only). (default: vmexit) 112-k:: 113--key=<value>:: 114 Sorting key. Possible values: sample (default, sort by samples 115 number), time (sort by average time). 116-p:: 117--pid=:: 118 Analyze events only for given process ID(s) (comma separated list). 119 120STAT LIVE OPTIONS 121----------------- 122-d:: 123--display:: 124 Time in seconds between display updates 125 126-m:: 127--mmap-pages=:: 128 Number of mmap data pages (must be a power of two) or size 129 specification with appended unit character - B/K/M/G. The 130 size is rounded up to have nearest pages power of two value. 131 132-a:: 133--all-cpus:: 134 System-wide collection from all CPUs. 135 136-p:: 137--pid=:: 138 Analyze events only for given process ID(s) (comma separated list). 139 140--vcpu=<value>:: 141 analyze events which occur on this vcpu. (default: all vcpus) 142 143 144--event=<value>:: 145 event to be analyzed. Possible values: vmexit, 146 mmio (x86 only), ioport (x86 only). 147 (default: vmexit) 148 149-k:: 150--key=<value>:: 151 Sorting key. Possible values: sample (default, sort by samples 152 number), time (sort by average time). 153 154--duration=<value>:: 155 Show events other than HLT (x86 only) or Wait state (s390 only) 156 that take longer than duration usecs. 157 158--proc-map-timeout:: 159 When processing pre-existing threads /proc/XXX/mmap, it may take 160 a long time, because the file may be huge. A time out is needed 161 in such cases. 162 This option sets the time out limit. The default value is 500 ms. 163 164SEE ALSO 165-------- 166linkperf:perf-top[1], linkperf:perf-record[1], linkperf:perf-report[1], 167linkperf:perf-diff[1], linkperf:perf-buildid-list[1], 168linkperf:perf-stat[1] 169