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>
36 * Released under the GPL v2. (and only v2, not any later version)
41 #include "util/util.h"
42 #include "util/parse-options.h"
43 #include "util/parse-events.h"
45 #include <sys/prctl.h>
47 static struct perf_counter_attr default_attrs[MAX_COUNTERS] = {
49 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
50 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES},
51 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
52 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
54 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES },
55 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS },
56 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES},
57 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES },
61 static int system_wide = 0;
62 static int inherit = 1;
63 static int verbose = 0;
65 static int fd[MAX_NR_CPUS][MAX_COUNTERS];
67 static int target_pid = -1;
68 static int nr_cpus = 0;
69 static unsigned int page_size;
73 static const unsigned int default_count[] = {
82 static __u64 event_res[MAX_COUNTERS][3];
83 static __u64 event_scaled[MAX_COUNTERS];
85 static __u64 runtime_nsecs;
86 static __u64 walltime_nsecs;
87 static __u64 runtime_cycles;
89 static void create_perf_stat_counter(int counter)
91 struct perf_counter_attr *attr = attrs + counter;
94 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
95 PERF_FORMAT_TOTAL_TIME_RUNNING;
99 for (cpu = 0; cpu < nr_cpus; cpu ++) {
100 fd[cpu][counter] = sys_perf_counter_open(attr, -1, cpu, -1, 0);
101 if (fd[cpu][counter] < 0 && verbose) {
102 printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[cpu][counter], strerror(errno));
106 attr->inherit = inherit;
109 fd[0][counter] = sys_perf_counter_open(attr, 0, -1, -1, 0);
110 if (fd[0][counter] < 0 && verbose) {
111 printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[0][counter], strerror(errno));
117 * Does the counter have nsecs as a unit?
119 static inline int nsec_counter(int counter)
121 if (attrs[counter].type != PERF_TYPE_SOFTWARE)
124 if (attrs[counter].config == PERF_COUNT_SW_CPU_CLOCK)
127 if (attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK)
134 * Read out the results of a single counter:
136 static void read_counter(int counter)
138 __u64 *count, single_count[3];
143 count = event_res[counter];
145 count[0] = count[1] = count[2] = 0;
148 for (cpu = 0; cpu < nr_cpus; cpu ++) {
149 if (fd[cpu][counter] < 0)
152 res = read(fd[cpu][counter], single_count, nv * sizeof(__u64));
153 assert(res == nv * sizeof(__u64));
155 count[0] += single_count[0];
157 count[1] += single_count[1];
158 count[2] += single_count[2];
165 event_scaled[counter] = -1;
170 if (count[2] < count[1]) {
171 event_scaled[counter] = 1;
172 count[0] = (unsigned long long)
173 ((double)count[0] * count[1] / count[2] + 0.5);
177 * Save the full runtime - to allow normalization during printout:
179 if (attrs[counter].type == PERF_TYPE_SOFTWARE &&
180 attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK)
181 runtime_nsecs = count[0];
182 if (attrs[counter].type == PERF_TYPE_HARDWARE &&
183 attrs[counter].config == PERF_COUNT_HW_CPU_CYCLES)
184 runtime_cycles = count[0];
188 * Print out the results of a single counter:
190 static void print_counter(int counter)
195 count = event_res[counter];
196 scaled = event_scaled[counter];
199 fprintf(stderr, " %14s %-20s\n",
200 "<not counted>", event_name(counter));
204 if (nsec_counter(counter)) {
205 double msecs = (double)count[0] / 1000000;
207 fprintf(stderr, " %14.6f %-20s",
208 msecs, event_name(counter));
209 if (attrs[counter].type == PERF_TYPE_SOFTWARE &&
210 attrs[counter].config == PERF_COUNT_SW_TASK_CLOCK) {
213 fprintf(stderr, " # %11.3f CPU utilization factor",
214 (double)count[0] / (double)walltime_nsecs);
217 fprintf(stderr, " %14Ld %-20s",
218 count[0], event_name(counter));
220 fprintf(stderr, " # %11.3f M/sec",
221 (double)count[0]/runtime_nsecs*1000.0);
222 if (runtime_cycles &&
223 attrs[counter].type == PERF_TYPE_HARDWARE &&
224 attrs[counter].config == PERF_COUNT_HW_INSTRUCTIONS) {
226 fprintf(stderr, " # %1.3f per cycle",
227 (double)count[0] / (double)runtime_cycles);
231 fprintf(stderr, " (scaled from %.2f%%)",
232 (double) count[2] / count[1] * 100);
233 fprintf(stderr, "\n");
236 static int do_perf_stat(int argc, const char **argv)
238 unsigned long long t0, t1;
247 for (counter = 0; counter < nr_counters; counter++)
248 create_perf_stat_counter(counter);
251 * Enable counters and exec the command:
254 prctl(PR_TASK_PERF_COUNTERS_ENABLE);
256 if ((pid = fork()) < 0)
257 perror("failed to fork");
260 if (execvp(argv[0], (char **)argv)) {
266 while (wait(&status) >= 0)
269 prctl(PR_TASK_PERF_COUNTERS_DISABLE);
272 walltime_nsecs = t1 - t0;
276 fprintf(stderr, "\n");
277 fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
279 for (i = 1; i < argc; i++)
280 fprintf(stderr, " %s", argv[i]);
282 fprintf(stderr, "\':\n");
283 fprintf(stderr, "\n");
285 for (counter = 0; counter < nr_counters; counter++)
286 read_counter(counter);
288 for (counter = 0; counter < nr_counters; counter++)
289 print_counter(counter);
292 fprintf(stderr, "\n");
293 fprintf(stderr, " Wall-clock time elapsed: %12.6f msecs\n",
294 (double)(t1-t0)/1e6);
295 fprintf(stderr, "\n");
300 static volatile int signr = -1;
302 static void skip_signal(int signo)
307 static void sig_atexit(void)
312 signal(signr, SIG_DFL);
313 kill(getpid(), signr);
316 static const char * const stat_usage[] = {
317 "perf stat [<options>] <command>",
321 static const struct option options[] = {
322 OPT_CALLBACK('e', "event", NULL, "event",
323 "event selector. use 'perf list' to list available events",
325 OPT_BOOLEAN('i', "inherit", &inherit,
326 "child tasks inherit counters"),
327 OPT_INTEGER('p', "pid", &target_pid,
328 "stat events on existing pid"),
329 OPT_BOOLEAN('a', "all-cpus", &system_wide,
330 "system-wide collection from all CPUs"),
331 OPT_BOOLEAN('S', "scale", &scale,
332 "scale/normalize counters"),
333 OPT_BOOLEAN('v', "verbose", &verbose,
334 "be more verbose (show counter open errors, etc)"),
338 int cmd_stat(int argc, const char **argv, const char *prefix)
340 page_size = sysconf(_SC_PAGE_SIZE);
342 memcpy(attrs, default_attrs, sizeof(attrs));
344 argc = parse_options(argc, argv, options, stat_usage, 0);
346 usage_with_options(stat_usage, options);
351 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
352 assert(nr_cpus <= MAX_NR_CPUS);
353 assert(nr_cpus >= 0);
356 * We dont want to block the signals - that would cause
357 * child tasks to inherit that and Ctrl-C would not work.
358 * What we want is for Ctrl-C to work in the exec()-ed
359 * task, but being ignored by perf stat itself:
362 signal(SIGINT, skip_signal);
363 signal(SIGALRM, skip_signal);
364 signal(SIGABRT, skip_signal);
366 return do_perf_stat(argc, argv);