![Frederic Weisbecker](/assets/img/avatar_default.png)
Building builtin-stat.c reports the following errors: cc1: warnings being treated as errors builtin-stat.c: In function ‘run_perf_stat’: builtin-stat.c:242: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result builtin-stat.c:255: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result make: *** [builtin-stat.o] Erreur 1 This patch handles the possible pipe read failures. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1246474930-6088-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
552 lines
13 KiB
C
552 lines
13 KiB
C
/*
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* builtin-stat.c
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*
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* Builtin stat command: Give a precise performance counters summary
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* overview about any workload, CPU or specific PID.
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*
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* Sample output:
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$ perf stat ~/hackbench 10
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Time: 0.104
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Performance counter stats for '/home/mingo/hackbench':
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1255.538611 task clock ticks # 10.143 CPU utilization factor
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54011 context switches # 0.043 M/sec
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385 CPU migrations # 0.000 M/sec
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17755 pagefaults # 0.014 M/sec
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3808323185 CPU cycles # 3033.219 M/sec
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1575111190 instructions # 1254.530 M/sec
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17367895 cache references # 13.833 M/sec
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7674421 cache misses # 6.112 M/sec
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Wall-clock time elapsed: 123.786620 msecs
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*
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* Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
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*
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* Improvements and fixes by:
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*
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* Arjan van de Ven <arjan@linux.intel.com>
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* Yanmin Zhang <yanmin.zhang@intel.com>
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* Wu Fengguang <fengguang.wu@intel.com>
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* Mike Galbraith <efault@gmx.de>
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* Paul Mackerras <paulus@samba.org>
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* Jaswinder Singh Rajput <jaswinder@kernel.org>
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*
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* Released under the GPL v2. (and only v2, not any later version)
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*/
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#include "perf.h"
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#include "builtin.h"
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#include "util/util.h"
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#include "util/parse-options.h"
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#include "util/parse-events.h"
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#include <sys/prctl.h>
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#include <math.h>
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static struct perf_counter_attr default_attrs[] = {
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{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
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{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES},
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{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
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{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
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{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES },
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{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS },
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{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES},
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{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES },
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};
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#define MAX_RUN 100
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static int system_wide = 0;
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static int verbose = 0;
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static unsigned int nr_cpus = 0;
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static int run_idx = 0;
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static int run_count = 1;
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static int inherit = 1;
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static int scale = 1;
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static int target_pid = -1;
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static int null_run = 0;
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static int fd[MAX_NR_CPUS][MAX_COUNTERS];
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static u64 runtime_nsecs[MAX_RUN];
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static u64 walltime_nsecs[MAX_RUN];
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static u64 runtime_cycles[MAX_RUN];
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static u64 event_res[MAX_RUN][MAX_COUNTERS][3];
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static u64 event_scaled[MAX_RUN][MAX_COUNTERS];
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static u64 event_res_avg[MAX_COUNTERS][3];
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static u64 event_res_noise[MAX_COUNTERS][3];
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static u64 event_scaled_avg[MAX_COUNTERS];
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static u64 runtime_nsecs_avg;
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static u64 runtime_nsecs_noise;
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static u64 walltime_nsecs_avg;
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static u64 walltime_nsecs_noise;
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static u64 runtime_cycles_avg;
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static u64 runtime_cycles_noise;
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#define MATCH_EVENT(t, c, counter) \
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(attrs[counter].type == PERF_TYPE_##t && \
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attrs[counter].config == PERF_COUNT_##c)
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#define ERR_PERF_OPEN \
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"Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n"
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static void create_perf_stat_counter(int counter, int pid)
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{
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struct perf_counter_attr *attr = attrs + counter;
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if (scale)
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attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
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PERF_FORMAT_TOTAL_TIME_RUNNING;
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if (system_wide) {
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unsigned int cpu;
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for (cpu = 0; cpu < nr_cpus; cpu++) {
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fd[cpu][counter] = sys_perf_counter_open(attr, -1, cpu, -1, 0);
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if (fd[cpu][counter] < 0 && verbose)
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fprintf(stderr, ERR_PERF_OPEN, counter,
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fd[cpu][counter], strerror(errno));
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}
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} else {
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attr->inherit = inherit;
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attr->disabled = 1;
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attr->enable_on_exec = 1;
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fd[0][counter] = sys_perf_counter_open(attr, pid, -1, -1, 0);
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if (fd[0][counter] < 0 && verbose)
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fprintf(stderr, ERR_PERF_OPEN, counter,
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fd[0][counter], strerror(errno));
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}
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}
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/*
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* Does the counter have nsecs as a unit?
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*/
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static inline int nsec_counter(int counter)
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{
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if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
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MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
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return 1;
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return 0;
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}
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/*
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* Read out the results of a single counter:
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*/
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static void read_counter(int counter)
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{
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u64 *count, single_count[3];
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unsigned int cpu;
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size_t res, nv;
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int scaled;
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count = event_res[run_idx][counter];
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count[0] = count[1] = count[2] = 0;
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nv = scale ? 3 : 1;
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for (cpu = 0; cpu < nr_cpus; cpu++) {
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if (fd[cpu][counter] < 0)
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continue;
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res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
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assert(res == nv * sizeof(u64));
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close(fd[cpu][counter]);
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fd[cpu][counter] = -1;
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count[0] += single_count[0];
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if (scale) {
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count[1] += single_count[1];
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count[2] += single_count[2];
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}
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}
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scaled = 0;
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if (scale) {
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if (count[2] == 0) {
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event_scaled[run_idx][counter] = -1;
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count[0] = 0;
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return;
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}
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if (count[2] < count[1]) {
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event_scaled[run_idx][counter] = 1;
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count[0] = (unsigned long long)
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((double)count[0] * count[1] / count[2] + 0.5);
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}
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}
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/*
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* Save the full runtime - to allow normalization during printout:
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*/
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if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
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runtime_nsecs[run_idx] = count[0];
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if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
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runtime_cycles[run_idx] = count[0];
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}
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static int run_perf_stat(int argc __used, const char **argv)
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{
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unsigned long long t0, t1;
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int status = 0;
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int counter;
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int pid;
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int child_ready_pipe[2], go_pipe[2];
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char buf;
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if (!system_wide)
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nr_cpus = 1;
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if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
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perror("failed to create pipes");
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exit(1);
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}
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if ((pid = fork()) < 0)
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perror("failed to fork");
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if (!pid) {
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close(child_ready_pipe[0]);
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close(go_pipe[1]);
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fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
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/*
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* Do a dummy execvp to get the PLT entry resolved,
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* so we avoid the resolver overhead on the real
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* execvp call.
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*/
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execvp("", (char **)argv);
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/*
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* Tell the parent we're ready to go
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*/
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close(child_ready_pipe[1]);
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/*
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* Wait until the parent tells us to go.
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*/
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if (read(go_pipe[0], &buf, 1) == -1)
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perror("unable to read pipe");
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execvp(argv[0], (char **)argv);
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perror(argv[0]);
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exit(-1);
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}
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/*
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* Wait for the child to be ready to exec.
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*/
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close(child_ready_pipe[1]);
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close(go_pipe[0]);
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if (read(child_ready_pipe[0], &buf, 1) == -1)
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perror("unable to read pipe");
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close(child_ready_pipe[0]);
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for (counter = 0; counter < nr_counters; counter++)
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create_perf_stat_counter(counter, pid);
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/*
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* Enable counters and exec the command:
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*/
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t0 = rdclock();
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close(go_pipe[1]);
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wait(&status);
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t1 = rdclock();
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walltime_nsecs[run_idx] = t1 - t0;
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for (counter = 0; counter < nr_counters; counter++)
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read_counter(counter);
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return WEXITSTATUS(status);
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}
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static void print_noise(u64 *count, u64 *noise)
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{
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if (run_count > 1)
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fprintf(stderr, " ( +- %7.3f%% )",
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(double)noise[0]/(count[0]+1)*100.0);
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}
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static void nsec_printout(int counter, u64 *count, u64 *noise)
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{
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double msecs = (double)count[0] / 1000000;
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fprintf(stderr, " %14.6f %-24s", msecs, event_name(counter));
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if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
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if (walltime_nsecs_avg)
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fprintf(stderr, " # %10.3f CPUs ",
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(double)count[0] / (double)walltime_nsecs_avg);
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}
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print_noise(count, noise);
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}
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static void abs_printout(int counter, u64 *count, u64 *noise)
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{
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fprintf(stderr, " %14Ld %-24s", count[0], event_name(counter));
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if (runtime_cycles_avg &&
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MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
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fprintf(stderr, " # %10.3f IPC ",
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(double)count[0] / (double)runtime_cycles_avg);
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} else {
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if (runtime_nsecs_avg) {
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fprintf(stderr, " # %10.3f M/sec",
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(double)count[0]/runtime_nsecs_avg*1000.0);
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}
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}
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print_noise(count, noise);
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}
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/*
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* Print out the results of a single counter:
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*/
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static void print_counter(int counter)
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{
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u64 *count, *noise;
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int scaled;
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count = event_res_avg[counter];
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noise = event_res_noise[counter];
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scaled = event_scaled_avg[counter];
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if (scaled == -1) {
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fprintf(stderr, " %14s %-24s\n",
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"<not counted>", event_name(counter));
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return;
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}
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if (nsec_counter(counter))
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nsec_printout(counter, count, noise);
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else
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abs_printout(counter, count, noise);
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if (scaled)
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fprintf(stderr, " (scaled from %.2f%%)",
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(double) count[2] / count[1] * 100);
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fprintf(stderr, "\n");
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}
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/*
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* normalize_noise noise values down to stddev:
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*/
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static void normalize_noise(u64 *val)
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{
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double res;
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res = (double)*val / (run_count * sqrt((double)run_count));
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*val = (u64)res;
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}
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static void update_avg(const char *name, int idx, u64 *avg, u64 *val)
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{
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*avg += *val;
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if (verbose > 1)
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fprintf(stderr, "debug: %20s[%d]: %Ld\n", name, idx, *val);
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}
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/*
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* Calculate the averages and noises:
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*/
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static void calc_avg(void)
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{
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int i, j;
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if (verbose > 1)
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fprintf(stderr, "\n");
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for (i = 0; i < run_count; i++) {
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update_avg("runtime", 0, &runtime_nsecs_avg, runtime_nsecs + i);
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update_avg("walltime", 0, &walltime_nsecs_avg, walltime_nsecs + i);
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update_avg("runtime_cycles", 0, &runtime_cycles_avg, runtime_cycles + i);
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for (j = 0; j < nr_counters; j++) {
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update_avg("counter/0", j,
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event_res_avg[j]+0, event_res[i][j]+0);
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update_avg("counter/1", j,
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event_res_avg[j]+1, event_res[i][j]+1);
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update_avg("counter/2", j,
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event_res_avg[j]+2, event_res[i][j]+2);
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if (event_scaled[i][j] != (u64)-1)
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update_avg("scaled", j,
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event_scaled_avg + j, event_scaled[i]+j);
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else
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event_scaled_avg[j] = -1;
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}
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}
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runtime_nsecs_avg /= run_count;
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walltime_nsecs_avg /= run_count;
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runtime_cycles_avg /= run_count;
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for (j = 0; j < nr_counters; j++) {
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event_res_avg[j][0] /= run_count;
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event_res_avg[j][1] /= run_count;
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event_res_avg[j][2] /= run_count;
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}
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for (i = 0; i < run_count; i++) {
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runtime_nsecs_noise +=
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abs((s64)(runtime_nsecs[i] - runtime_nsecs_avg));
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walltime_nsecs_noise +=
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abs((s64)(walltime_nsecs[i] - walltime_nsecs_avg));
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runtime_cycles_noise +=
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abs((s64)(runtime_cycles[i] - runtime_cycles_avg));
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for (j = 0; j < nr_counters; j++) {
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event_res_noise[j][0] +=
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abs((s64)(event_res[i][j][0] - event_res_avg[j][0]));
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event_res_noise[j][1] +=
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abs((s64)(event_res[i][j][1] - event_res_avg[j][1]));
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event_res_noise[j][2] +=
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abs((s64)(event_res[i][j][2] - event_res_avg[j][2]));
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}
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}
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normalize_noise(&runtime_nsecs_noise);
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normalize_noise(&walltime_nsecs_noise);
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normalize_noise(&runtime_cycles_noise);
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for (j = 0; j < nr_counters; j++) {
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normalize_noise(&event_res_noise[j][0]);
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normalize_noise(&event_res_noise[j][1]);
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normalize_noise(&event_res_noise[j][2]);
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}
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}
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static void print_stat(int argc, const char **argv)
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{
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int i, counter;
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calc_avg();
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fflush(stdout);
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fprintf(stderr, "\n");
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fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
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for (i = 1; i < argc; i++)
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fprintf(stderr, " %s", argv[i]);
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fprintf(stderr, "\'");
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if (run_count > 1)
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fprintf(stderr, " (%d runs)", run_count);
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fprintf(stderr, ":\n\n");
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for (counter = 0; counter < nr_counters; counter++)
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print_counter(counter);
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fprintf(stderr, "\n");
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fprintf(stderr, " %14.9f seconds time elapsed",
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(double)walltime_nsecs_avg/1e9);
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if (run_count > 1) {
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fprintf(stderr, " ( +- %7.3f%% )",
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100.0*(double)walltime_nsecs_noise/(double)walltime_nsecs_avg);
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}
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fprintf(stderr, "\n\n");
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}
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static volatile int signr = -1;
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static void skip_signal(int signo)
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{
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signr = signo;
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}
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static void sig_atexit(void)
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{
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if (signr == -1)
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return;
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signal(signr, SIG_DFL);
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kill(getpid(), signr);
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}
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static const char * const stat_usage[] = {
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"perf stat [<options>] <command>",
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NULL
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};
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static const struct option options[] = {
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OPT_CALLBACK('e', "event", NULL, "event",
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"event selector. use 'perf list' to list available events",
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parse_events),
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OPT_BOOLEAN('i', "inherit", &inherit,
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"child tasks inherit counters"),
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OPT_INTEGER('p', "pid", &target_pid,
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"stat events on existing pid"),
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OPT_BOOLEAN('a', "all-cpus", &system_wide,
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"system-wide collection from all CPUs"),
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OPT_BOOLEAN('S', "scale", &scale,
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"scale/normalize counters"),
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|
OPT_BOOLEAN('v', "verbose", &verbose,
|
|
"be more verbose (show counter open errors, etc)"),
|
|
OPT_INTEGER('r', "repeat", &run_count,
|
|
"repeat command and print average + stddev (max: 100)"),
|
|
OPT_BOOLEAN('n', "null", &null_run,
|
|
"null run - dont start any counters"),
|
|
OPT_END()
|
|
};
|
|
|
|
int cmd_stat(int argc, const char **argv, const char *prefix __used)
|
|
{
|
|
int status;
|
|
|
|
argc = parse_options(argc, argv, options, stat_usage, 0);
|
|
if (!argc)
|
|
usage_with_options(stat_usage, options);
|
|
if (run_count <= 0 || run_count > MAX_RUN)
|
|
usage_with_options(stat_usage, options);
|
|
|
|
/* Set attrs and nr_counters if no event is selected and !null_run */
|
|
if (!null_run && !nr_counters) {
|
|
memcpy(attrs, default_attrs, sizeof(default_attrs));
|
|
nr_counters = ARRAY_SIZE(default_attrs);
|
|
}
|
|
|
|
nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
|
|
assert(nr_cpus <= MAX_NR_CPUS);
|
|
assert((int)nr_cpus >= 0);
|
|
|
|
/*
|
|
* We dont want to block the signals - that would cause
|
|
* child tasks to inherit that and Ctrl-C would not work.
|
|
* What we want is for Ctrl-C to work in the exec()-ed
|
|
* task, but being ignored by perf stat itself:
|
|
*/
|
|
atexit(sig_atexit);
|
|
signal(SIGINT, skip_signal);
|
|
signal(SIGALRM, skip_signal);
|
|
signal(SIGABRT, skip_signal);
|
|
|
|
status = 0;
|
|
for (run_idx = 0; run_idx < run_count; run_idx++) {
|
|
if (run_count != 1 && verbose)
|
|
fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
|
|
status = run_perf_stat(argc, argv);
|
|
}
|
|
|
|
print_stat(argc, argv);
|
|
|
|
return status;
|
|
}
|