4 * Builtin stat command: Give a precise performance counters summary
5 * overview about any workload, CPU or specific PID.
9 $ perf stat ~/hackbench 10
12 Performance counter stats for '/home/mingo/hackbench':
14 1255.538611 task clock ticks # 10.143 CPU utilization factor
15 54011 context switches # 0.043 M/sec
16 385 CPU migrations # 0.000 M/sec
17 17755 pagefaults # 0.014 M/sec
18 3808323185 CPU cycles # 3033.219 M/sec
19 1575111190 instructions # 1254.530 M/sec
20 17367895 cache references # 13.833 M/sec
21 7674421 cache misses # 6.112 M/sec
23 Wall-clock time elapsed: 123.786620 msecs
26 * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
28 * Improvements and fixes by:
30 * Arjan van de Ven <arjan@linux.intel.com>
31 * Yanmin Zhang <yanmin.zhang@intel.com>
32 * Wu Fengguang <fengguang.wu@intel.com>
33 * Mike Galbraith <efault@gmx.de>
34 * Paul Mackerras <paulus@samba.org>
35 * Jaswinder Singh Rajput <jaswinder@kernel.org>
37 * Released under the GPL v2. (and only v2, not any later version)
42 #include "util/util.h"
43 #include "util/parse-options.h"
44 #include "util/parse-events.h"
45 #include "util/event.h"
46 #include "util/debug.h"
47 #include "util/header.h"
48 #include "util/cpumap.h"
49 #include "util/thread.h"
51 #include <sys/prctl.h>
55 static struct perf_event_attr default_attrs
[] = {
57 { .type
= PERF_TYPE_SOFTWARE
, .config
= PERF_COUNT_SW_TASK_CLOCK
},
58 { .type
= PERF_TYPE_SOFTWARE
, .config
= PERF_COUNT_SW_CONTEXT_SWITCHES
},
59 { .type
= PERF_TYPE_SOFTWARE
, .config
= PERF_COUNT_SW_CPU_MIGRATIONS
},
60 { .type
= PERF_TYPE_SOFTWARE
, .config
= PERF_COUNT_SW_PAGE_FAULTS
},
62 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_CPU_CYCLES
},
63 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_INSTRUCTIONS
},
64 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_BRANCH_INSTRUCTIONS
},
65 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_BRANCH_MISSES
},
66 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_CACHE_REFERENCES
},
67 { .type
= PERF_TYPE_HARDWARE
, .config
= PERF_COUNT_HW_CACHE_MISSES
},
71 static bool system_wide
= false;
72 static unsigned int nr_cpus
= 0;
73 static int run_idx
= 0;
75 static int run_count
= 1;
76 static bool no_inherit
= false;
77 static bool scale
= true;
78 static pid_t target_pid
= -1;
79 static pid_t target_tid
= -1;
80 static pid_t
*all_tids
= NULL
;
81 static int thread_num
= 0;
82 static pid_t child_pid
= -1;
83 static bool null_run
= false;
84 static bool big_num
= false;
87 static int *fd
[MAX_NR_CPUS
][MAX_COUNTERS
];
89 static int event_scaled
[MAX_COUNTERS
];
91 static volatile int done
= 0;
98 static void update_stats(struct stats
*stats
, u64 val
)
103 delta
= val
- stats
->mean
;
104 stats
->mean
+= delta
/ stats
->n
;
105 stats
->M2
+= delta
*(val
- stats
->mean
);
108 static double avg_stats(struct stats
*stats
)
114 * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
116 * (\Sum n_i^2) - ((\Sum n_i)^2)/n
117 * s^2 = -------------------------------
120 * http://en.wikipedia.org/wiki/Stddev
122 * The std dev of the mean is related to the std dev by:
129 static double stddev_stats(struct stats
*stats
)
131 double variance
= stats
->M2
/ (stats
->n
- 1);
132 double variance_mean
= variance
/ stats
->n
;
134 return sqrt(variance_mean
);
137 struct stats event_res_stats
[MAX_COUNTERS
][3];
138 struct stats runtime_nsecs_stats
;
139 struct stats walltime_nsecs_stats
;
140 struct stats runtime_cycles_stats
;
141 struct stats runtime_branches_stats
;
143 #define MATCH_EVENT(t, c, counter) \
144 (attrs[counter].type == PERF_TYPE_##t && \
145 attrs[counter].config == PERF_COUNT_##c)
147 #define ERR_PERF_OPEN \
148 "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
150 static int create_perf_stat_counter(int counter
)
152 struct perf_event_attr
*attr
= attrs
+ counter
;
157 attr
->read_format
= PERF_FORMAT_TOTAL_TIME_ENABLED
|
158 PERF_FORMAT_TOTAL_TIME_RUNNING
;
163 for (cpu
= 0; cpu
< nr_cpus
; cpu
++) {
164 fd
[cpu
][counter
][0] = sys_perf_event_open(attr
,
165 -1, cpumap
[cpu
], -1, 0);
166 if (fd
[cpu
][counter
][0] < 0)
167 pr_debug(ERR_PERF_OPEN
, counter
,
168 fd
[cpu
][counter
][0], strerror(errno
));
173 attr
->inherit
= !no_inherit
;
174 if (target_pid
== -1 && target_tid
== -1) {
176 attr
->enable_on_exec
= 1;
178 for (thread
= 0; thread
< thread_num
; thread
++) {
179 fd
[0][counter
][thread
] = sys_perf_event_open(attr
,
180 all_tids
[thread
], -1, -1, 0);
181 if (fd
[0][counter
][thread
] < 0)
182 pr_debug(ERR_PERF_OPEN
, counter
,
183 fd
[0][counter
][thread
],
194 * Does the counter have nsecs as a unit?
196 static inline int nsec_counter(int counter
)
198 if (MATCH_EVENT(SOFTWARE
, SW_CPU_CLOCK
, counter
) ||
199 MATCH_EVENT(SOFTWARE
, SW_TASK_CLOCK
, counter
))
206 * Read out the results of a single counter:
208 static void read_counter(int counter
)
210 u64 count
[3], single_count
[3];
216 count
[0] = count
[1] = count
[2] = 0;
219 for (cpu
= 0; cpu
< nr_cpus
; cpu
++) {
220 for (thread
= 0; thread
< thread_num
; thread
++) {
221 if (fd
[cpu
][counter
][thread
] < 0)
224 res
= read(fd
[cpu
][counter
][thread
],
225 single_count
, nv
* sizeof(u64
));
226 assert(res
== nv
* sizeof(u64
));
228 close(fd
[cpu
][counter
][thread
]);
229 fd
[cpu
][counter
][thread
] = -1;
231 count
[0] += single_count
[0];
233 count
[1] += single_count
[1];
234 count
[2] += single_count
[2];
242 event_scaled
[counter
] = -1;
247 if (count
[2] < count
[1]) {
248 event_scaled
[counter
] = 1;
249 count
[0] = (unsigned long long)
250 ((double)count
[0] * count
[1] / count
[2] + 0.5);
254 for (i
= 0; i
< 3; i
++)
255 update_stats(&event_res_stats
[counter
][i
], count
[i
]);
258 fprintf(stderr
, "%s: %Ld %Ld %Ld\n", event_name(counter
),
259 count
[0], count
[1], count
[2]);
263 * Save the full runtime - to allow normalization during printout:
265 if (MATCH_EVENT(SOFTWARE
, SW_TASK_CLOCK
, counter
))
266 update_stats(&runtime_nsecs_stats
, count
[0]);
267 if (MATCH_EVENT(HARDWARE
, HW_CPU_CYCLES
, counter
))
268 update_stats(&runtime_cycles_stats
, count
[0]);
269 if (MATCH_EVENT(HARDWARE
, HW_BRANCH_INSTRUCTIONS
, counter
))
270 update_stats(&runtime_branches_stats
, count
[0]);
273 static int run_perf_stat(int argc __used
, const char **argv
)
275 unsigned long long t0
, t1
;
277 int counter
, ncreated
= 0;
278 int child_ready_pipe
[2], go_pipe
[2];
279 const bool forks
= (argc
> 0);
285 if (forks
&& (pipe(child_ready_pipe
) < 0 || pipe(go_pipe
) < 0)) {
286 perror("failed to create pipes");
291 if ((child_pid
= fork()) < 0)
292 perror("failed to fork");
295 close(child_ready_pipe
[0]);
297 fcntl(go_pipe
[0], F_SETFD
, FD_CLOEXEC
);
300 * Do a dummy execvp to get the PLT entry resolved,
301 * so we avoid the resolver overhead on the real
304 execvp("", (char **)argv
);
307 * Tell the parent we're ready to go
309 close(child_ready_pipe
[1]);
312 * Wait until the parent tells us to go.
314 if (read(go_pipe
[0], &buf
, 1) == -1)
315 perror("unable to read pipe");
317 execvp(argv
[0], (char **)argv
);
323 if (target_tid
== -1 && target_pid
== -1 && !system_wide
)
324 all_tids
[0] = child_pid
;
327 * Wait for the child to be ready to exec.
329 close(child_ready_pipe
[1]);
331 if (read(child_ready_pipe
[0], &buf
, 1) == -1)
332 perror("unable to read pipe");
333 close(child_ready_pipe
[0]);
336 for (counter
= 0; counter
< nr_counters
; counter
++)
337 ncreated
+= create_perf_stat_counter(counter
);
340 pr_err("No permission to collect %sstats.\n"
341 "Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n",
342 system_wide
? "system-wide " : "");
344 kill(child_pid
, SIGTERM
);
349 * Enable counters and exec the command:
357 while(!done
) sleep(1);
362 update_stats(&walltime_nsecs_stats
, t1
- t0
);
364 for (counter
= 0; counter
< nr_counters
; counter
++)
365 read_counter(counter
);
367 return WEXITSTATUS(status
);
370 static void print_noise(int counter
, double avg
)
375 fprintf(stderr
, " ( +- %7.3f%% )",
376 100 * stddev_stats(&event_res_stats
[counter
][0]) / avg
);
379 static void nsec_printout(int counter
, double avg
)
381 double msecs
= avg
/ 1e6
;
383 fprintf(stderr
, " %18.6f %-24s", msecs
, event_name(counter
));
385 if (MATCH_EVENT(SOFTWARE
, SW_TASK_CLOCK
, counter
)) {
386 fprintf(stderr
, " # %10.3f CPUs ",
387 avg
/ avg_stats(&walltime_nsecs_stats
));
391 static void abs_printout(int counter
, double avg
)
393 double total
, ratio
= 0.0;
396 fprintf(stderr
, " %'18.0f %-24s", avg
, event_name(counter
));
398 fprintf(stderr
, " %18.0f %-24s", avg
, event_name(counter
));
400 if (MATCH_EVENT(HARDWARE
, HW_INSTRUCTIONS
, counter
)) {
401 total
= avg_stats(&runtime_cycles_stats
);
406 fprintf(stderr
, " # %10.3f IPC ", ratio
);
407 } else if (MATCH_EVENT(HARDWARE
, HW_BRANCH_MISSES
, counter
) &&
408 runtime_branches_stats
.n
!= 0) {
409 total
= avg_stats(&runtime_branches_stats
);
412 ratio
= avg
* 100 / total
;
414 fprintf(stderr
, " # %10.3f %% ", ratio
);
416 } else if (runtime_nsecs_stats
.n
!= 0) {
417 total
= avg_stats(&runtime_nsecs_stats
);
420 ratio
= 1000.0 * avg
/ total
;
422 fprintf(stderr
, " # %10.3f M/sec", ratio
);
427 * Print out the results of a single counter:
429 static void print_counter(int counter
)
431 double avg
= avg_stats(&event_res_stats
[counter
][0]);
432 int scaled
= event_scaled
[counter
];
435 fprintf(stderr
, " %18s %-24s\n",
436 "<not counted>", event_name(counter
));
440 if (nsec_counter(counter
))
441 nsec_printout(counter
, avg
);
443 abs_printout(counter
, avg
);
445 print_noise(counter
, avg
);
448 double avg_enabled
, avg_running
;
450 avg_enabled
= avg_stats(&event_res_stats
[counter
][1]);
451 avg_running
= avg_stats(&event_res_stats
[counter
][2]);
453 fprintf(stderr
, " (scaled from %.2f%%)",
454 100 * avg_running
/ avg_enabled
);
457 fprintf(stderr
, "\n");
460 static void print_stat(int argc
, const char **argv
)
466 fprintf(stderr
, "\n");
467 fprintf(stderr
, " Performance counter stats for ");
468 if(target_pid
== -1 && target_tid
== -1) {
469 fprintf(stderr
, "\'%s", argv
[0]);
470 for (i
= 1; i
< argc
; i
++)
471 fprintf(stderr
, " %s", argv
[i
]);
472 } else if (target_pid
!= -1)
473 fprintf(stderr
, "process id \'%d", target_pid
);
475 fprintf(stderr
, "thread id \'%d", target_tid
);
477 fprintf(stderr
, "\'");
479 fprintf(stderr
, " (%d runs)", run_count
);
480 fprintf(stderr
, ":\n\n");
482 for (counter
= 0; counter
< nr_counters
; counter
++)
483 print_counter(counter
);
485 fprintf(stderr
, "\n");
486 fprintf(stderr
, " %18.9f seconds time elapsed",
487 avg_stats(&walltime_nsecs_stats
)/1e9
);
489 fprintf(stderr
, " ( +- %7.3f%% )",
490 100*stddev_stats(&walltime_nsecs_stats
) /
491 avg_stats(&walltime_nsecs_stats
));
493 fprintf(stderr
, "\n\n");
496 static volatile int signr
= -1;
498 static void skip_signal(int signo
)
506 static void sig_atexit(void)
509 kill(child_pid
, SIGTERM
);
514 signal(signr
, SIG_DFL
);
515 kill(getpid(), signr
);
518 static const char * const stat_usage
[] = {
519 "perf stat [<options>] [<command>]",
523 static const struct option options
[] = {
524 OPT_CALLBACK('e', "event", NULL
, "event",
525 "event selector. use 'perf list' to list available events",
527 OPT_BOOLEAN('i', "no-inherit", &no_inherit
,
528 "child tasks do not inherit counters"),
529 OPT_INTEGER('p', "pid", &target_pid
,
530 "stat events on existing process id"),
531 OPT_INTEGER('t', "tid", &target_tid
,
532 "stat events on existing thread id"),
533 OPT_BOOLEAN('a', "all-cpus", &system_wide
,
534 "system-wide collection from all CPUs"),
535 OPT_BOOLEAN('c', "scale", &scale
,
536 "scale/normalize counters"),
537 OPT_INCR('v', "verbose", &verbose
,
538 "be more verbose (show counter open errors, etc)"),
539 OPT_INTEGER('r', "repeat", &run_count
,
540 "repeat command and print average + stddev (max: 100)"),
541 OPT_BOOLEAN('n', "null", &null_run
,
542 "null run - dont start any counters"),
543 OPT_BOOLEAN('B', "big-num", &big_num
,
544 "print large numbers with thousands\' separators"),
548 int cmd_stat(int argc
, const char **argv
, const char *prefix __used
)
553 setlocale(LC_ALL
, "");
555 argc
= parse_options(argc
, argv
, options
, stat_usage
,
556 PARSE_OPT_STOP_AT_NON_OPTION
);
557 if (!argc
&& target_pid
== -1 && target_tid
== -1)
558 usage_with_options(stat_usage
, options
);
560 usage_with_options(stat_usage
, options
);
562 /* Set attrs and nr_counters if no event is selected and !null_run */
563 if (!null_run
&& !nr_counters
) {
564 memcpy(attrs
, default_attrs
, sizeof(default_attrs
));
565 nr_counters
= ARRAY_SIZE(default_attrs
);
569 nr_cpus
= read_cpu_map();
573 if (target_pid
!= -1) {
574 target_tid
= target_pid
;
575 thread_num
= find_all_tid(target_pid
, &all_tids
);
576 if (thread_num
<= 0) {
577 fprintf(stderr
, "Can't find all threads of pid %d\n",
579 usage_with_options(stat_usage
, options
);
582 all_tids
=malloc(sizeof(pid_t
));
586 all_tids
[0] = target_tid
;
590 for (i
= 0; i
< MAX_NR_CPUS
; i
++) {
591 for (j
= 0; j
< MAX_COUNTERS
; j
++) {
592 fd
[i
][j
] = malloc(sizeof(int)*thread_num
);
599 * We dont want to block the signals - that would cause
600 * child tasks to inherit that and Ctrl-C would not work.
601 * What we want is for Ctrl-C to work in the exec()-ed
602 * task, but being ignored by perf stat itself:
605 signal(SIGINT
, skip_signal
);
606 signal(SIGALRM
, skip_signal
);
607 signal(SIGABRT
, skip_signal
);
610 for (run_idx
= 0; run_idx
< run_count
; run_idx
++) {
611 if (run_count
!= 1 && verbose
)
612 fprintf(stderr
, "[ perf stat: executing run #%d ... ]\n", run_idx
+ 1);
613 status
= run_perf_stat(argc
, argv
);
617 print_stat(argc
, argv
);