1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 29cfe06f8SSteven Rostedt /* 39cfe06f8SSteven Rostedt * If TRACE_SYSTEM is defined, that will be the directory created 44e20e3a6SSteven Rostedt (Red Hat) * in the ftrace directory under /sys/kernel/tracing/events/<system> 59cfe06f8SSteven Rostedt * 644ad18e0SSteven Rostedt * The define_trace.h below will also look for a file name of 79cfe06f8SSteven Rostedt * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here. 867aedeb8SChunyan Zhang * In this case, it would look for sample-trace.h 99cfe06f8SSteven Rostedt * 1044ad18e0SSteven Rostedt * If the header name will be different than the system name 1144ad18e0SSteven Rostedt * (as in this case), then you can override the header name that 1244ad18e0SSteven Rostedt * define_trace.h will look up by defining TRACE_INCLUDE_FILE 139cfe06f8SSteven Rostedt * 1444ad18e0SSteven Rostedt * This file is called trace-events-sample.h but we want the system 1567aedeb8SChunyan Zhang * to be called "sample-trace". Therefore we must define the name of this 1644ad18e0SSteven Rostedt * file: 179cfe06f8SSteven Rostedt * 1844ad18e0SSteven Rostedt * #define TRACE_INCLUDE_FILE trace-events-sample 199cfe06f8SSteven Rostedt * 2044ad18e0SSteven Rostedt * As we do an the bottom of this file. 21d0b6e04aSLi Zefan * 22d0b6e04aSLi Zefan * Notice that TRACE_SYSTEM should be defined outside of #if 23d0b6e04aSLi Zefan * protection, just like TRACE_INCLUDE_FILE. 249cfe06f8SSteven Rostedt */ 259cfe06f8SSteven Rostedt #undef TRACE_SYSTEM 2688920427SSteven Rostedt (Red Hat) #define TRACE_SYSTEM sample-trace 2788920427SSteven Rostedt (Red Hat) 2888920427SSteven Rostedt (Red Hat) /* 2988920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric 3088920427SSteven Rostedt (Red Hat) * and underscore), although it may start with numbers. If for some 3188920427SSteven Rostedt (Red Hat) * reason it is not, you need to add the following lines: 3288920427SSteven Rostedt (Red Hat) */ 3388920427SSteven Rostedt (Red Hat) #undef TRACE_SYSTEM_VAR 3488920427SSteven Rostedt (Red Hat) #define TRACE_SYSTEM_VAR sample_trace 3588920427SSteven Rostedt (Red Hat) /* 3688920427SSteven Rostedt (Red Hat) * But the above is only needed if TRACE_SYSTEM is not alpha-numeric 3788920427SSteven Rostedt (Red Hat) * and underscored. By default, TRACE_SYSTEM_VAR will be equal to 3888920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if 3988920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with 4088920427SSteven Rostedt (Red Hat) * only alpha-numeric and underscores. 4188920427SSteven Rostedt (Red Hat) * 4288920427SSteven Rostedt (Red Hat) * The TRACE_SYSTEM_VAR is only used internally and not visible to 4388920427SSteven Rostedt (Red Hat) * user space. 4488920427SSteven Rostedt (Red Hat) */ 459cfe06f8SSteven Rostedt 469cfe06f8SSteven Rostedt /* 47d0b6e04aSLi Zefan * Notice that this file is not protected like a normal header. 48d0b6e04aSLi Zefan * We also must allow for rereading of this file. The 49d0b6e04aSLi Zefan * 50d0b6e04aSLi Zefan * || defined(TRACE_HEADER_MULTI_READ) 51d0b6e04aSLi Zefan * 52d0b6e04aSLi Zefan * serves this purpose. 53d0b6e04aSLi Zefan */ 54d0b6e04aSLi Zefan #if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ) 55d0b6e04aSLi Zefan #define _TRACE_EVENT_SAMPLE_H 56d0b6e04aSLi Zefan 57d0b6e04aSLi Zefan /* 58d0b6e04aSLi Zefan * All trace headers should include tracepoint.h, until we finally 59d0b6e04aSLi Zefan * make it into a standard header. 60d0b6e04aSLi Zefan */ 61d0b6e04aSLi Zefan #include <linux/tracepoint.h> 62d0b6e04aSLi Zefan 63d0b6e04aSLi Zefan /* 649cfe06f8SSteven Rostedt * The TRACE_EVENT macro is broken up into 5 parts. 659cfe06f8SSteven Rostedt * 669cfe06f8SSteven Rostedt * name: name of the trace point. This is also how to enable the tracepoint. 679cfe06f8SSteven Rostedt * A function called trace_foo_bar() will be created. 689cfe06f8SSteven Rostedt * 699cfe06f8SSteven Rostedt * proto: the prototype of the function trace_foo_bar() 709cfe06f8SSteven Rostedt * Here it is trace_foo_bar(char *foo, int bar). 719cfe06f8SSteven Rostedt * 729cfe06f8SSteven Rostedt * args: must match the arguments in the prototype. 739cfe06f8SSteven Rostedt * Here it is simply "foo, bar". 749cfe06f8SSteven Rostedt * 759cfe06f8SSteven Rostedt * struct: This defines the way the data will be stored in the ring buffer. 764e20e3a6SSteven Rostedt (Red Hat) * The items declared here become part of a special structure 774e20e3a6SSteven Rostedt (Red Hat) * called "__entry", which can be used in the fast_assign part of the 784e20e3a6SSteven Rostedt (Red Hat) * TRACE_EVENT macro. 799cfe06f8SSteven Rostedt * 804e20e3a6SSteven Rostedt (Red Hat) * Here are the currently defined types you can use: 814e20e3a6SSteven Rostedt (Red Hat) * 824e20e3a6SSteven Rostedt (Red Hat) * __field : Is broken up into type and name. Where type can be any 834e20e3a6SSteven Rostedt (Red Hat) * primitive type (integer, long or pointer). 844e20e3a6SSteven Rostedt (Red Hat) * 854e20e3a6SSteven Rostedt (Red Hat) * __field(int, foo) 864e20e3a6SSteven Rostedt (Red Hat) * 874e20e3a6SSteven Rostedt (Red Hat) * __entry->foo = 5; 884e20e3a6SSteven Rostedt (Red Hat) * 894e20e3a6SSteven Rostedt (Red Hat) * __field_struct : This can be any static complex data type (struct, union 904e20e3a6SSteven Rostedt (Red Hat) * but not an array). Be careful using complex types, as each 914e20e3a6SSteven Rostedt (Red Hat) * event is limited in size, and copying large amounts of data 924e20e3a6SSteven Rostedt (Red Hat) * into the ring buffer can slow things down. 934e20e3a6SSteven Rostedt (Red Hat) * 944e20e3a6SSteven Rostedt (Red Hat) * __field_struct(struct bar, foo) 954e20e3a6SSteven Rostedt (Red Hat) * 964e20e3a6SSteven Rostedt (Red Hat) * __entry->bar.x = y; 974e20e3a6SSteven Rostedt (Red Hat) 984e20e3a6SSteven Rostedt (Red Hat) * __array: There are three fields (type, name, size). The type is the 9927019975SJeremy Linton * type of elements in the array, the name is the name of the array. 1004e20e3a6SSteven Rostedt (Red Hat) * size is the number of items in the array (not the total size). 1014e20e3a6SSteven Rostedt (Red Hat) * 1024e20e3a6SSteven Rostedt (Red Hat) * __array( char, foo, 10) is the same as saying: char foo[10]; 1034e20e3a6SSteven Rostedt (Red Hat) * 1044e20e3a6SSteven Rostedt (Red Hat) * Assigning arrays can be done like any array: 1054e20e3a6SSteven Rostedt (Red Hat) * 1064e20e3a6SSteven Rostedt (Red Hat) * __entry->foo[0] = 'a'; 1074e20e3a6SSteven Rostedt (Red Hat) * 1084e20e3a6SSteven Rostedt (Red Hat) * memcpy(__entry->foo, bar, 10); 1094e20e3a6SSteven Rostedt (Red Hat) * 11067aedeb8SChunyan Zhang * __dynamic_array: This is similar to array, but can vary its size from 1114e20e3a6SSteven Rostedt (Red Hat) * instance to instance of the tracepoint being called. 1124e20e3a6SSteven Rostedt (Red Hat) * Like __array, this too has three elements (type, name, size); 1134e20e3a6SSteven Rostedt (Red Hat) * type is the type of the element, name is the name of the array. 1144e20e3a6SSteven Rostedt (Red Hat) * The size is different than __array. It is not a static number, 1154e20e3a6SSteven Rostedt (Red Hat) * but the algorithm to figure out the length of the array for the 11627019975SJeremy Linton * specific instance of tracepoint. Again, size is the number of 1174e20e3a6SSteven Rostedt (Red Hat) * items in the array, not the total length in bytes. 1184e20e3a6SSteven Rostedt (Red Hat) * 1194e20e3a6SSteven Rostedt (Red Hat) * __dynamic_array( int, foo, bar) is similar to: int foo[bar]; 1204e20e3a6SSteven Rostedt (Red Hat) * 1214e20e3a6SSteven Rostedt (Red Hat) * Note, unlike arrays, you must use the __get_dynamic_array() macro 1224e20e3a6SSteven Rostedt (Red Hat) * to access the array. 1234e20e3a6SSteven Rostedt (Red Hat) * 1244e20e3a6SSteven Rostedt (Red Hat) * memcpy(__get_dynamic_array(foo), bar, 10); 1254e20e3a6SSteven Rostedt (Red Hat) * 1264e20e3a6SSteven Rostedt (Red Hat) * Notice, that "__entry" is not needed here. 1274e20e3a6SSteven Rostedt (Red Hat) * 1284e20e3a6SSteven Rostedt (Red Hat) * __string: This is a special kind of __dynamic_array. It expects to 12927019975SJeremy Linton * have a null terminated character array passed to it (it allows 1304e20e3a6SSteven Rostedt (Red Hat) * for NULL too, which would be converted into "(null)"). __string 13127019975SJeremy Linton * takes two parameter (name, src), where name is the name of 1324e20e3a6SSteven Rostedt (Red Hat) * the string saved, and src is the string to copy into the 1334e20e3a6SSteven Rostedt (Red Hat) * ring buffer. 1344e20e3a6SSteven Rostedt (Red Hat) * 1354e20e3a6SSteven Rostedt (Red Hat) * __string(foo, bar) is similar to: strcpy(foo, bar) 1364e20e3a6SSteven Rostedt (Red Hat) * 1374e20e3a6SSteven Rostedt (Red Hat) * To assign a string, use the helper macro __assign_str(). 1384e20e3a6SSteven Rostedt (Red Hat) * 1394e20e3a6SSteven Rostedt (Red Hat) * __assign_str(foo, bar); 1404e20e3a6SSteven Rostedt (Red Hat) * 1414e20e3a6SSteven Rostedt (Red Hat) * In most cases, the __assign_str() macro will take the same 1424e20e3a6SSteven Rostedt (Red Hat) * parameters as the __string() macro had to declare the string. 1434e20e3a6SSteven Rostedt (Red Hat) * 144883b4aeeSSteven Rostedt (VMware) * __string_len: This is a helper to a __dynamic_array, but it understands 145883b4aeeSSteven Rostedt (VMware) * that the array has characters in it, and with the combined 146883b4aeeSSteven Rostedt (VMware) * use of __assign_str_len(), it will allocate 'len' + 1 bytes 147883b4aeeSSteven Rostedt (VMware) * in the ring buffer and add a '\0' to the string. This is 148883b4aeeSSteven Rostedt (VMware) * useful if the string being saved has no terminating '\0' byte. 149883b4aeeSSteven Rostedt (VMware) * It requires that the length of the string is known as it acts 150883b4aeeSSteven Rostedt (VMware) * like a memcpy(). 151883b4aeeSSteven Rostedt (VMware) * 152883b4aeeSSteven Rostedt (VMware) * Declared with: 153883b4aeeSSteven Rostedt (VMware) * 154883b4aeeSSteven Rostedt (VMware) * __string_len(foo, bar, len) 155883b4aeeSSteven Rostedt (VMware) * 156883b4aeeSSteven Rostedt (VMware) * To assign this string, use the helper macro __assign_str_len(). 157883b4aeeSSteven Rostedt (VMware) * 158*ecbe794eSGeliang Tang * __assign_str_len(foo, bar, len); 159883b4aeeSSteven Rostedt (VMware) * 160883b4aeeSSteven Rostedt (VMware) * Then len + 1 is allocated to the ring buffer, and a nul terminating 161883b4aeeSSteven Rostedt (VMware) * byte is added. This is similar to: 162883b4aeeSSteven Rostedt (VMware) * 163883b4aeeSSteven Rostedt (VMware) * memcpy(__get_str(foo), bar, len); 164883b4aeeSSteven Rostedt (VMware) * __get_str(foo)[len] = 0; 165883b4aeeSSteven Rostedt (VMware) * 166883b4aeeSSteven Rostedt (VMware) * The advantage of using this over __dynamic_array, is that it 167883b4aeeSSteven Rostedt (VMware) * takes care of allocating the extra byte on the ring buffer 168883b4aeeSSteven Rostedt (VMware) * for the '\0' terminating byte, and __get_str(foo) can be used 169883b4aeeSSteven Rostedt (VMware) * in the TP_printk(). 170883b4aeeSSteven Rostedt (VMware) * 1714e20e3a6SSteven Rostedt (Red Hat) * __bitmask: This is another kind of __dynamic_array, but it expects 1724e20e3a6SSteven Rostedt (Red Hat) * an array of longs, and the number of bits to parse. It takes 1734e20e3a6SSteven Rostedt (Red Hat) * two parameters (name, nr_bits), where name is the name of the 1744e20e3a6SSteven Rostedt (Red Hat) * bitmask to save, and the nr_bits is the number of bits to record. 1754e20e3a6SSteven Rostedt (Red Hat) * 1764e20e3a6SSteven Rostedt (Red Hat) * __bitmask(target_cpu, nr_cpumask_bits) 1774e20e3a6SSteven Rostedt (Red Hat) * 1784e20e3a6SSteven Rostedt (Red Hat) * To assign a bitmask, use the __assign_bitmask() helper macro. 1794e20e3a6SSteven Rostedt (Red Hat) * 1804e20e3a6SSteven Rostedt (Red Hat) * __assign_bitmask(target_cpus, cpumask_bits(bar), nr_cpumask_bits); 1814e20e3a6SSteven Rostedt (Red Hat) * 1829cfe06f8SSteven Rostedt * 1839cfe06f8SSteven Rostedt * fast_assign: This is a C like function that is used to store the items 1844e20e3a6SSteven Rostedt (Red Hat) * into the ring buffer. A special variable called "__entry" will be the 1854e20e3a6SSteven Rostedt (Red Hat) * structure that points into the ring buffer and has the same fields as 1864e20e3a6SSteven Rostedt (Red Hat) * described by the struct part of TRACE_EVENT above. 1879cfe06f8SSteven Rostedt * 1889cfe06f8SSteven Rostedt * printk: This is a way to print out the data in pretty print. This is 1899cfe06f8SSteven Rostedt * useful if the system crashes and you are logging via a serial line, 1909cfe06f8SSteven Rostedt * the data can be printed to the console using this "printk" method. 1914e20e3a6SSteven Rostedt (Red Hat) * This is also used to print out the data from the trace files. 1924e20e3a6SSteven Rostedt (Red Hat) * Again, the __entry macro is used to access the data from the ring buffer. 1934e20e3a6SSteven Rostedt (Red Hat) * 1944e20e3a6SSteven Rostedt (Red Hat) * Note, __dynamic_array, __string, and __bitmask require special helpers 1954e20e3a6SSteven Rostedt (Red Hat) * to access the data. 1964e20e3a6SSteven Rostedt (Red Hat) * 1974e20e3a6SSteven Rostedt (Red Hat) * For __dynamic_array(int, foo, bar) use __get_dynamic_array(foo) 1984e20e3a6SSteven Rostedt (Red Hat) * Use __get_dynamic_array_len(foo) to get the length of the array 199d6726c81SSteven Rostedt (Red Hat) * saved. Note, __get_dynamic_array_len() returns the total allocated 200d6726c81SSteven Rostedt (Red Hat) * length of the dynamic array; __print_array() expects the second 201d6726c81SSteven Rostedt (Red Hat) * parameter to be the number of elements. To get that, the array length 202d6726c81SSteven Rostedt (Red Hat) * needs to be divided by the element size. 2034e20e3a6SSteven Rostedt (Red Hat) * 2044e20e3a6SSteven Rostedt (Red Hat) * For __string(foo, bar) use __get_str(foo) 2054e20e3a6SSteven Rostedt (Red Hat) * 2064e20e3a6SSteven Rostedt (Red Hat) * For __bitmask(target_cpus, nr_cpumask_bits) use __get_bitmask(target_cpus) 2074e20e3a6SSteven Rostedt (Red Hat) * 2089cfe06f8SSteven Rostedt * 2099cfe06f8SSteven Rostedt * Note, that for both the assign and the printk, __entry is the handler 2109cfe06f8SSteven Rostedt * to the data structure in the ring buffer, and is defined by the 2119cfe06f8SSteven Rostedt * TP_STRUCT__entry. 2129cfe06f8SSteven Rostedt */ 2134e20e3a6SSteven Rostedt (Red Hat) 2144e20e3a6SSteven Rostedt (Red Hat) /* 2154e20e3a6SSteven Rostedt (Red Hat) * It is OK to have helper functions in the file, but they need to be protected 2164e20e3a6SSteven Rostedt (Red Hat) * from being defined more than once. Remember, this file gets included more 2174e20e3a6SSteven Rostedt (Red Hat) * than once. 2184e20e3a6SSteven Rostedt (Red Hat) */ 2194e20e3a6SSteven Rostedt (Red Hat) #ifndef __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS 2204e20e3a6SSteven Rostedt (Red Hat) #define __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS 2214e20e3a6SSteven Rostedt (Red Hat) static inline int __length_of(const int *list) 2224e20e3a6SSteven Rostedt (Red Hat) { 2234e20e3a6SSteven Rostedt (Red Hat) int i; 2244e20e3a6SSteven Rostedt (Red Hat) 2254e20e3a6SSteven Rostedt (Red Hat) if (!list) 2264e20e3a6SSteven Rostedt (Red Hat) return 0; 2274e20e3a6SSteven Rostedt (Red Hat) 2284e20e3a6SSteven Rostedt (Red Hat) for (i = 0; list[i]; i++) 2294e20e3a6SSteven Rostedt (Red Hat) ; 2304e20e3a6SSteven Rostedt (Red Hat) return i; 2314e20e3a6SSteven Rostedt (Red Hat) } 23232eb3d0dSSteven Rostedt (Red Hat) 23332eb3d0dSSteven Rostedt (Red Hat) enum { 23432eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_FOO = 2, 23532eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_BAR = 4, 23632eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_ZOO = 8, 23732eb3d0dSSteven Rostedt (Red Hat) }; 2384e20e3a6SSteven Rostedt (Red Hat) #endif 2394e20e3a6SSteven Rostedt (Red Hat) 24032eb3d0dSSteven Rostedt (Red Hat) /* 24132eb3d0dSSteven Rostedt (Red Hat) * If enums are used in the TP_printk(), their names will be shown in 24232eb3d0dSSteven Rostedt (Red Hat) * format files and not their values. This can cause problems with user 24332eb3d0dSSteven Rostedt (Red Hat) * space programs that parse the format files to know how to translate 24432eb3d0dSSteven Rostedt (Red Hat) * the raw binary trace output into human readable text. 24532eb3d0dSSteven Rostedt (Red Hat) * 24632eb3d0dSSteven Rostedt (Red Hat) * To help out user space programs, any enum that is used in the TP_printk() 24732eb3d0dSSteven Rostedt (Red Hat) * should be defined by TRACE_DEFINE_ENUM() macro. All that is needed to 24832eb3d0dSSteven Rostedt (Red Hat) * be done is to add this macro with the enum within it in the trace 24932eb3d0dSSteven Rostedt (Red Hat) * header file, and it will be converted in the output. 25032eb3d0dSSteven Rostedt (Red Hat) */ 25132eb3d0dSSteven Rostedt (Red Hat) 25232eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_FOO); 25332eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_BAR); 25432eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_ZOO); 25532eb3d0dSSteven Rostedt (Red Hat) 2569cfe06f8SSteven Rostedt TRACE_EVENT(foo_bar, 2579cfe06f8SSteven Rostedt 2584e20e3a6SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar, const int *lst, 2594e20e3a6SSteven Rostedt (Red Hat) const char *string, const struct cpumask *mask), 2609cfe06f8SSteven Rostedt 2614e20e3a6SSteven Rostedt (Red Hat) TP_ARGS(foo, bar, lst, string, mask), 2629cfe06f8SSteven Rostedt 2639cfe06f8SSteven Rostedt TP_STRUCT__entry( 2649cfe06f8SSteven Rostedt __array( char, foo, 10 ) 2659cfe06f8SSteven Rostedt __field( int, bar ) 2664e20e3a6SSteven Rostedt (Red Hat) __dynamic_array(int, list, __length_of(lst)) 2674e20e3a6SSteven Rostedt (Red Hat) __string( str, string ) 2684e20e3a6SSteven Rostedt (Red Hat) __bitmask( cpus, num_possible_cpus() ) 2699cfe06f8SSteven Rostedt ), 2709cfe06f8SSteven Rostedt 2719cfe06f8SSteven Rostedt TP_fast_assign( 272d8fae2f6SZhao Hongjiang strlcpy(__entry->foo, foo, 10); 2739cfe06f8SSteven Rostedt __entry->bar = bar; 2744e20e3a6SSteven Rostedt (Red Hat) memcpy(__get_dynamic_array(list), lst, 2754e20e3a6SSteven Rostedt (Red Hat) __length_of(lst) * sizeof(int)); 2764e20e3a6SSteven Rostedt (Red Hat) __assign_str(str, string); 2774e20e3a6SSteven Rostedt (Red Hat) __assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus()); 2789cfe06f8SSteven Rostedt ), 2799cfe06f8SSteven Rostedt 28032eb3d0dSSteven Rostedt (Red Hat) TP_printk("foo %s %d %s %s %s %s (%s)", __entry->foo, __entry->bar, 28132eb3d0dSSteven Rostedt (Red Hat) 28232eb3d0dSSteven Rostedt (Red Hat) /* 28332eb3d0dSSteven Rostedt (Red Hat) * Notice here the use of some helper functions. This includes: 28432eb3d0dSSteven Rostedt (Red Hat) * 28532eb3d0dSSteven Rostedt (Red Hat) * __print_symbolic( variable, { value, "string" }, ... ), 28632eb3d0dSSteven Rostedt (Red Hat) * 28732eb3d0dSSteven Rostedt (Red Hat) * The variable is tested against each value of the { } pair. If 28832eb3d0dSSteven Rostedt (Red Hat) * the variable matches one of the values, then it will print the 28932eb3d0dSSteven Rostedt (Red Hat) * string in that pair. If non are matched, it returns a string 29032eb3d0dSSteven Rostedt (Red Hat) * version of the number (if __entry->bar == 7 then "7" is returned). 29132eb3d0dSSteven Rostedt (Red Hat) */ 29232eb3d0dSSteven Rostedt (Red Hat) __print_symbolic(__entry->bar, 29332eb3d0dSSteven Rostedt (Red Hat) { 0, "zero" }, 29432eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_FOO, "TWO" }, 29532eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_BAR, "FOUR" }, 29632eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_ZOO, "EIGHT" }, 29732eb3d0dSSteven Rostedt (Red Hat) { 10, "TEN" } 29832eb3d0dSSteven Rostedt (Red Hat) ), 29932eb3d0dSSteven Rostedt (Red Hat) 30032eb3d0dSSteven Rostedt (Red Hat) /* 30132eb3d0dSSteven Rostedt (Red Hat) * __print_flags( variable, "delim", { value, "flag" }, ... ), 30232eb3d0dSSteven Rostedt (Red Hat) * 30332eb3d0dSSteven Rostedt (Red Hat) * This is similar to __print_symbolic, except that it tests the bits 30432eb3d0dSSteven Rostedt (Red Hat) * of the value. If ((FLAG & variable) == FLAG) then the string is 30532eb3d0dSSteven Rostedt (Red Hat) * printed. If more than one flag matches, then each one that does is 30632eb3d0dSSteven Rostedt (Red Hat) * also printed with delim in between them. 30732eb3d0dSSteven Rostedt (Red Hat) * If not all bits are accounted for, then the not found bits will be 30832eb3d0dSSteven Rostedt (Red Hat) * added in hex format: 0x506 will show BIT2|BIT4|0x500 30932eb3d0dSSteven Rostedt (Red Hat) */ 31032eb3d0dSSteven Rostedt (Red Hat) __print_flags(__entry->bar, "|", 31132eb3d0dSSteven Rostedt (Red Hat) { 1, "BIT1" }, 31232eb3d0dSSteven Rostedt (Red Hat) { 2, "BIT2" }, 31332eb3d0dSSteven Rostedt (Red Hat) { 4, "BIT3" }, 31432eb3d0dSSteven Rostedt (Red Hat) { 8, "BIT4" } 31532eb3d0dSSteven Rostedt (Red Hat) ), 31632eb3d0dSSteven Rostedt (Red Hat) /* 31732eb3d0dSSteven Rostedt (Red Hat) * __print_array( array, len, element_size ) 31832eb3d0dSSteven Rostedt (Red Hat) * 31932eb3d0dSSteven Rostedt (Red Hat) * This prints out the array that is defined by __array in a nice format. 32032eb3d0dSSteven Rostedt (Red Hat) */ 3214e20e3a6SSteven Rostedt (Red Hat) __print_array(__get_dynamic_array(list), 322d6726c81SSteven Rostedt (Red Hat) __get_dynamic_array_len(list) / sizeof(int), 3234e20e3a6SSteven Rostedt (Red Hat) sizeof(int)), 3244e20e3a6SSteven Rostedt (Red Hat) __get_str(str), __get_bitmask(cpus)) 3259cfe06f8SSteven Rostedt ); 326c4c7eb29SSteven Rostedt (Red Hat) 327c4c7eb29SSteven Rostedt (Red Hat) /* 328c4c7eb29SSteven Rostedt (Red Hat) * There may be a case where a tracepoint should only be called if 329c4c7eb29SSteven Rostedt (Red Hat) * some condition is set. Otherwise the tracepoint should not be called. 330c4c7eb29SSteven Rostedt (Red Hat) * But to do something like: 331c4c7eb29SSteven Rostedt (Red Hat) * 332c4c7eb29SSteven Rostedt (Red Hat) * if (cond) 333c4c7eb29SSteven Rostedt (Red Hat) * trace_foo(); 334c4c7eb29SSteven Rostedt (Red Hat) * 335c4c7eb29SSteven Rostedt (Red Hat) * Would cause a little overhead when tracing is not enabled, and that 336c4c7eb29SSteven Rostedt (Red Hat) * overhead, even if small, is not something we want. As tracepoints 337c4c7eb29SSteven Rostedt (Red Hat) * use static branch (aka jump_labels), where no branch is taken to 338c4c7eb29SSteven Rostedt (Red Hat) * skip the tracepoint when not enabled, and a jmp is placed to jump 339c4c7eb29SSteven Rostedt (Red Hat) * to the tracepoint code when it is enabled, having a if statement 340c4c7eb29SSteven Rostedt (Red Hat) * nullifies that optimization. It would be nice to place that 341c4c7eb29SSteven Rostedt (Red Hat) * condition within the static branch. This is where TRACE_EVENT_CONDITION 342c4c7eb29SSteven Rostedt (Red Hat) * comes in. 343c4c7eb29SSteven Rostedt (Red Hat) * 344c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT_CONDITION() is just like TRACE_EVENT, except it adds another 345c4c7eb29SSteven Rostedt (Red Hat) * parameter just after args. Where TRACE_EVENT has: 346c4c7eb29SSteven Rostedt (Red Hat) * 347c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT(name, proto, args, struct, assign, printk) 348c4c7eb29SSteven Rostedt (Red Hat) * 349c4c7eb29SSteven Rostedt (Red Hat) * the CONDITION version has: 350c4c7eb29SSteven Rostedt (Red Hat) * 351c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT_CONDITION(name, proto, args, cond, struct, assign, printk) 352c4c7eb29SSteven Rostedt (Red Hat) * 353c4c7eb29SSteven Rostedt (Red Hat) * Everything is the same as TRACE_EVENT except for the new cond. Think 354c4c7eb29SSteven Rostedt (Red Hat) * of the cond variable as: 355c4c7eb29SSteven Rostedt (Red Hat) * 356c4c7eb29SSteven Rostedt (Red Hat) * if (cond) 357c4c7eb29SSteven Rostedt (Red Hat) * trace_foo_bar_with_cond(); 358c4c7eb29SSteven Rostedt (Red Hat) * 359c4c7eb29SSteven Rostedt (Red Hat) * Except that the logic for the if branch is placed after the static branch. 360c4c7eb29SSteven Rostedt (Red Hat) * That is, the if statement that processes the condition will not be 361c4c7eb29SSteven Rostedt (Red Hat) * executed unless that traecpoint is enabled. Otherwise it still remains 362c4c7eb29SSteven Rostedt (Red Hat) * a nop. 363c4c7eb29SSteven Rostedt (Red Hat) */ 364c4c7eb29SSteven Rostedt (Red Hat) TRACE_EVENT_CONDITION(foo_bar_with_cond, 365c4c7eb29SSteven Rostedt (Red Hat) 366c4c7eb29SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 367c4c7eb29SSteven Rostedt (Red Hat) 368c4c7eb29SSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 369c4c7eb29SSteven Rostedt (Red Hat) 370c4c7eb29SSteven Rostedt (Red Hat) TP_CONDITION(!(bar % 10)), 371c4c7eb29SSteven Rostedt (Red Hat) 372c4c7eb29SSteven Rostedt (Red Hat) TP_STRUCT__entry( 373c4c7eb29SSteven Rostedt (Red Hat) __string( foo, foo ) 374c4c7eb29SSteven Rostedt (Red Hat) __field( int, bar ) 375c4c7eb29SSteven Rostedt (Red Hat) ), 376c4c7eb29SSteven Rostedt (Red Hat) 377c4c7eb29SSteven Rostedt (Red Hat) TP_fast_assign( 378c4c7eb29SSteven Rostedt (Red Hat) __assign_str(foo, foo); 379c4c7eb29SSteven Rostedt (Red Hat) __entry->bar = bar; 380c4c7eb29SSteven Rostedt (Red Hat) ), 381c4c7eb29SSteven Rostedt (Red Hat) 382c4c7eb29SSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar) 383c4c7eb29SSteven Rostedt (Red Hat) ); 3846adc13f8SSteven Rostedt (Red Hat) 3858cf868afSSteven Rostedt (Red Hat) int foo_bar_reg(void); 3866adc13f8SSteven Rostedt (Red Hat) void foo_bar_unreg(void); 3876adc13f8SSteven Rostedt (Red Hat) 3886adc13f8SSteven Rostedt (Red Hat) /* 3896adc13f8SSteven Rostedt (Red Hat) * Now in the case that some function needs to be called when the 3906adc13f8SSteven Rostedt (Red Hat) * tracepoint is enabled and/or when it is disabled, the 3916adc13f8SSteven Rostedt (Red Hat) * TRACE_EVENT_FN() serves this purpose. This is just like TRACE_EVENT() 3926adc13f8SSteven Rostedt (Red Hat) * but adds two more parameters at the end: 3936adc13f8SSteven Rostedt (Red Hat) * 3946adc13f8SSteven Rostedt (Red Hat) * TRACE_EVENT_FN( name, proto, args, struct, assign, printk, reg, unreg) 3956adc13f8SSteven Rostedt (Red Hat) * 3966adc13f8SSteven Rostedt (Red Hat) * reg and unreg are functions with the prototype of: 3976adc13f8SSteven Rostedt (Red Hat) * 3986adc13f8SSteven Rostedt (Red Hat) * void reg(void) 3996adc13f8SSteven Rostedt (Red Hat) * 4006adc13f8SSteven Rostedt (Red Hat) * The reg function gets called before the tracepoint is enabled, and 4016adc13f8SSteven Rostedt (Red Hat) * the unreg function gets called after the tracepoint is disabled. 4026adc13f8SSteven Rostedt (Red Hat) * 4036adc13f8SSteven Rostedt (Red Hat) * Note, reg and unreg are allowed to be NULL. If you only need to 4046adc13f8SSteven Rostedt (Red Hat) * call a function before enabling, or after disabling, just set one 4056adc13f8SSteven Rostedt (Red Hat) * function and pass in NULL for the other parameter. 4066adc13f8SSteven Rostedt (Red Hat) */ 4076adc13f8SSteven Rostedt (Red Hat) TRACE_EVENT_FN(foo_bar_with_fn, 4086adc13f8SSteven Rostedt (Red Hat) 4096adc13f8SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 4106adc13f8SSteven Rostedt (Red Hat) 4116adc13f8SSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 4126adc13f8SSteven Rostedt (Red Hat) 4136adc13f8SSteven Rostedt (Red Hat) TP_STRUCT__entry( 4146adc13f8SSteven Rostedt (Red Hat) __string( foo, foo ) 4156adc13f8SSteven Rostedt (Red Hat) __field( int, bar ) 4166adc13f8SSteven Rostedt (Red Hat) ), 4176adc13f8SSteven Rostedt (Red Hat) 4186adc13f8SSteven Rostedt (Red Hat) TP_fast_assign( 4196adc13f8SSteven Rostedt (Red Hat) __assign_str(foo, foo); 4206adc13f8SSteven Rostedt (Red Hat) __entry->bar = bar; 4216adc13f8SSteven Rostedt (Red Hat) ), 4226adc13f8SSteven Rostedt (Red Hat) 4236adc13f8SSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar), 4246adc13f8SSteven Rostedt (Red Hat) 4256adc13f8SSteven Rostedt (Red Hat) foo_bar_reg, foo_bar_unreg 4266adc13f8SSteven Rostedt (Red Hat) ); 4276adc13f8SSteven Rostedt (Red Hat) 4287496946aSSteven Rostedt (Red Hat) /* 4297496946aSSteven Rostedt (Red Hat) * Each TRACE_EVENT macro creates several helper functions to produce 4307496946aSSteven Rostedt (Red Hat) * the code to add the tracepoint, create the files in the trace 4317496946aSSteven Rostedt (Red Hat) * directory, hook it to perf, assign the values and to print out 4327496946aSSteven Rostedt (Red Hat) * the raw data from the ring buffer. To prevent too much bloat, 4337496946aSSteven Rostedt (Red Hat) * if there are more than one tracepoint that uses the same format 4347496946aSSteven Rostedt (Red Hat) * for the proto, args, struct, assign and printk, and only the name 4357496946aSSteven Rostedt (Red Hat) * is different, it is highly recommended to use the DECLARE_EVENT_CLASS 4367496946aSSteven Rostedt (Red Hat) * 4377496946aSSteven Rostedt (Red Hat) * DECLARE_EVENT_CLASS() macro creates most of the functions for the 4387496946aSSteven Rostedt (Red Hat) * tracepoint. Then DEFINE_EVENT() is use to hook a tracepoint to those 4397496946aSSteven Rostedt (Red Hat) * functions. This DEFINE_EVENT() is an instance of the class and can 4407496946aSSteven Rostedt (Red Hat) * be enabled and disabled separately from other events (either TRACE_EVENT 4417496946aSSteven Rostedt (Red Hat) * or other DEFINE_EVENT()s). 4427496946aSSteven Rostedt (Red Hat) * 4437496946aSSteven Rostedt (Red Hat) * Note, TRACE_EVENT() itself is simply defined as: 4447496946aSSteven Rostedt (Red Hat) * 4457496946aSSteven Rostedt (Red Hat) * #define TRACE_EVENT(name, proto, args, tstruct, assign, printk) \ 446f094a233SWei Yang * DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \ 4477496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT(name, name, proto, args) 4487496946aSSteven Rostedt (Red Hat) * 4497496946aSSteven Rostedt (Red Hat) * The DEFINE_EVENT() also can be declared with conditions and reg functions: 4507496946aSSteven Rostedt (Red Hat) * 4517496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT_CONDITION(template, name, proto, args, cond); 4527496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT_FN(template, name, proto, args, reg, unreg); 4537496946aSSteven Rostedt (Red Hat) */ 4547496946aSSteven Rostedt (Red Hat) DECLARE_EVENT_CLASS(foo_template, 4557496946aSSteven Rostedt (Red Hat) 4567496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 4577496946aSSteven Rostedt (Red Hat) 4587496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 4597496946aSSteven Rostedt (Red Hat) 4607496946aSSteven Rostedt (Red Hat) TP_STRUCT__entry( 4617496946aSSteven Rostedt (Red Hat) __string( foo, foo ) 4627496946aSSteven Rostedt (Red Hat) __field( int, bar ) 4637496946aSSteven Rostedt (Red Hat) ), 4647496946aSSteven Rostedt (Red Hat) 4657496946aSSteven Rostedt (Red Hat) TP_fast_assign( 4667496946aSSteven Rostedt (Red Hat) __assign_str(foo, foo); 4677496946aSSteven Rostedt (Red Hat) __entry->bar = bar; 4687496946aSSteven Rostedt (Red Hat) ), 4697496946aSSteven Rostedt (Red Hat) 4707496946aSSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar) 4717496946aSSteven Rostedt (Red Hat) ); 4727496946aSSteven Rostedt (Red Hat) 4737496946aSSteven Rostedt (Red Hat) /* 4747496946aSSteven Rostedt (Red Hat) * Here's a better way for the previous samples (except, the first 47527019975SJeremy Linton * example had more fields and could not be used here). 4767496946aSSteven Rostedt (Red Hat) */ 4777496946aSSteven Rostedt (Red Hat) DEFINE_EVENT(foo_template, foo_with_template_simple, 4787496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 4797496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar)); 4807496946aSSteven Rostedt (Red Hat) 4817496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_CONDITION(foo_template, foo_with_template_cond, 4827496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 4837496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 4847496946aSSteven Rostedt (Red Hat) TP_CONDITION(!(bar % 8))); 4857496946aSSteven Rostedt (Red Hat) 4867496946aSSteven Rostedt (Red Hat) 4877496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_FN(foo_template, foo_with_template_fn, 4887496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 4897496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 4907496946aSSteven Rostedt (Red Hat) foo_bar_reg, foo_bar_unreg); 4917496946aSSteven Rostedt (Red Hat) 4927496946aSSteven Rostedt (Red Hat) /* 4937496946aSSteven Rostedt (Red Hat) * Anytime two events share basically the same values and have 4947496946aSSteven Rostedt (Red Hat) * the same output, use the DECLARE_EVENT_CLASS() and DEFINE_EVENT() 4957496946aSSteven Rostedt (Red Hat) * when ever possible. 4967496946aSSteven Rostedt (Red Hat) */ 4977496946aSSteven Rostedt (Red Hat) 4987496946aSSteven Rostedt (Red Hat) /* 4997496946aSSteven Rostedt (Red Hat) * If the event is similar to the DECLARE_EVENT_CLASS, but you need 5007496946aSSteven Rostedt (Red Hat) * to have a different output, then use DEFINE_EVENT_PRINT() which 5017496946aSSteven Rostedt (Red Hat) * lets you override the TP_printk() of the class. 5027496946aSSteven Rostedt (Red Hat) */ 5037496946aSSteven Rostedt (Red Hat) 5047496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_PRINT(foo_template, foo_with_template_print, 5057496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar), 5067496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar), 5077496946aSSteven Rostedt (Red Hat) TP_printk("bar %s %d", __get_str(foo), __entry->bar)); 5087496946aSSteven Rostedt (Red Hat) 509b466b133SMasami Hiramatsu /* 510b466b133SMasami Hiramatsu * There are yet another __rel_loc dynamic data attribute. If you 511b466b133SMasami Hiramatsu * use __rel_dynamic_array() and __rel_string() etc. macros, you 512b466b133SMasami Hiramatsu * can use this attribute. There is no difference from the viewpoint 513b466b133SMasami Hiramatsu * of functionality with/without 'rel' but the encoding is a bit 514b466b133SMasami Hiramatsu * different. This is expected to be used with user-space event, 515b466b133SMasami Hiramatsu * there is no reason that the kernel event use this, but only for 516b466b133SMasami Hiramatsu * testing. 517b466b133SMasami Hiramatsu */ 518b466b133SMasami Hiramatsu 519b466b133SMasami Hiramatsu TRACE_EVENT(foo_rel_loc, 520b466b133SMasami Hiramatsu 521b466b133SMasami Hiramatsu TP_PROTO(const char *foo, int bar, unsigned long *mask), 522b466b133SMasami Hiramatsu 523b466b133SMasami Hiramatsu TP_ARGS(foo, bar, mask), 524b466b133SMasami Hiramatsu 525b466b133SMasami Hiramatsu TP_STRUCT__entry( 526b466b133SMasami Hiramatsu __rel_string( foo, foo ) 527b466b133SMasami Hiramatsu __field( int, bar ) 528b466b133SMasami Hiramatsu __rel_bitmask( bitmask, 529b466b133SMasami Hiramatsu BITS_PER_BYTE * sizeof(unsigned long) ) 530b466b133SMasami Hiramatsu ), 531b466b133SMasami Hiramatsu 532b466b133SMasami Hiramatsu TP_fast_assign( 533b466b133SMasami Hiramatsu __assign_rel_str(foo, foo); 534b466b133SMasami Hiramatsu __entry->bar = bar; 535b466b133SMasami Hiramatsu __assign_rel_bitmask(bitmask, mask, 536b466b133SMasami Hiramatsu BITS_PER_BYTE * sizeof(unsigned long)); 537b466b133SMasami Hiramatsu ), 538b466b133SMasami Hiramatsu 539b466b133SMasami Hiramatsu TP_printk("foo_rel_loc %s, %d, %s", __get_rel_str(foo), __entry->bar, 540b466b133SMasami Hiramatsu __get_rel_bitmask(bitmask)) 541b466b133SMasami Hiramatsu ); 5429cfe06f8SSteven Rostedt #endif 5439cfe06f8SSteven Rostedt 5449cfe06f8SSteven Rostedt /***** NOTICE! The #if protection ends here. *****/ 5459cfe06f8SSteven Rostedt 5469cfe06f8SSteven Rostedt 5479cfe06f8SSteven Rostedt /* 5489cfe06f8SSteven Rostedt * There are several ways I could have done this. If I left out the 5499cfe06f8SSteven Rostedt * TRACE_INCLUDE_PATH, then it would default to the kernel source 5509cfe06f8SSteven Rostedt * include/trace/events directory. 5519cfe06f8SSteven Rostedt * 5529cfe06f8SSteven Rostedt * I could specify a path from the define_trace.h file back to this 5539cfe06f8SSteven Rostedt * file. 5549cfe06f8SSteven Rostedt * 5559cfe06f8SSteven Rostedt * #define TRACE_INCLUDE_PATH ../../samples/trace_events 5569cfe06f8SSteven Rostedt * 55744ad18e0SSteven Rostedt * But the safest and easiest way to simply make it use the directory 55844ad18e0SSteven Rostedt * that the file is in is to add in the Makefile: 5599cfe06f8SSteven Rostedt * 56044ad18e0SSteven Rostedt * CFLAGS_trace-events-sample.o := -I$(src) 5619cfe06f8SSteven Rostedt * 5629cfe06f8SSteven Rostedt * This will make sure the current path is part of the include 56344ad18e0SSteven Rostedt * structure for our file so that define_trace.h can find it. 5649cfe06f8SSteven Rostedt * 5659cfe06f8SSteven Rostedt * I could have made only the top level directory the include: 5669cfe06f8SSteven Rostedt * 5679cfe06f8SSteven Rostedt * CFLAGS_trace-events-sample.o := -I$(PWD) 5689cfe06f8SSteven Rostedt * 5699cfe06f8SSteven Rostedt * And then let the path to this directory be the TRACE_INCLUDE_PATH: 5709cfe06f8SSteven Rostedt * 5719cfe06f8SSteven Rostedt * #define TRACE_INCLUDE_PATH samples/trace_events 5729cfe06f8SSteven Rostedt * 57344ad18e0SSteven Rostedt * But then if something defines "samples" or "trace_events" as a macro 57444ad18e0SSteven Rostedt * then we could risk that being converted too, and give us an unexpected 5759cfe06f8SSteven Rostedt * result. 5769cfe06f8SSteven Rostedt */ 5779cfe06f8SSteven Rostedt #undef TRACE_INCLUDE_PATH 57871e1c8acSSteven Rostedt #undef TRACE_INCLUDE_FILE 5799cfe06f8SSteven Rostedt #define TRACE_INCLUDE_PATH . 58071e1c8acSSteven Rostedt /* 58171e1c8acSSteven Rostedt * TRACE_INCLUDE_FILE is not needed if the filename and TRACE_SYSTEM are equal 58271e1c8acSSteven Rostedt */ 58371e1c8acSSteven Rostedt #define TRACE_INCLUDE_FILE trace-events-sample 5849cfe06f8SSteven Rostedt #include <trace/define_trace.h> 585