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Diffstat (limited to 'tools/perf/builtin-stat.c')
-rw-r--r--tools/perf/builtin-stat.c54
1 files changed, 49 insertions, 5 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7e910bab1097..f686d5ff594e 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -87,7 +87,7 @@ static int run_count = 1;
static bool no_inherit = false;
static bool scale = true;
static enum aggr_mode aggr_mode = AGGR_GLOBAL;
-static pid_t child_pid = -1;
+static volatile pid_t child_pid = -1;
static bool null_run = false;
static int detailed_run = 0;
static bool big_num = true;
@@ -100,6 +100,7 @@ static const char *pre_cmd = NULL;
static const char *post_cmd = NULL;
static bool sync_run = false;
static unsigned int interval = 0;
+static unsigned int initial_delay = 0;
static bool forever = false;
static struct timespec ref_time;
static struct cpu_map *aggr_map;
@@ -254,7 +255,8 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
if (!perf_target__has_task(&target) &&
perf_evsel__is_group_leader(evsel)) {
attr->disabled = 1;
- attr->enable_on_exec = 1;
+ if (!initial_delay)
+ attr->enable_on_exec = 1;
}
return perf_evsel__open_per_thread(evsel, evsel_list->threads);
@@ -414,6 +416,22 @@ static void print_interval(void)
list_for_each_entry(counter, &evsel_list->entries, node)
print_counter_aggr(counter, prefix);
}
+
+ fflush(output);
+}
+
+static void handle_initial_delay(void)
+{
+ struct perf_evsel *counter;
+
+ if (initial_delay) {
+ const int ncpus = cpu_map__nr(evsel_list->cpus),
+ nthreads = thread_map__nr(evsel_list->threads);
+
+ usleep(initial_delay * 1000);
+ list_for_each_entry(counter, &evsel_list->entries, node)
+ perf_evsel__enable(counter, ncpus, nthreads);
+ }
}
static int __run_perf_stat(int argc, const char **argv)
@@ -486,6 +504,7 @@ static int __run_perf_stat(int argc, const char **argv)
if (forks) {
perf_evlist__start_workload(evsel_list);
+ handle_initial_delay();
if (interval) {
while (!waitpid(child_pid, &status, WNOHANG)) {
@@ -497,6 +516,7 @@ static int __run_perf_stat(int argc, const char **argv)
if (WIFSIGNALED(status))
psignal(WTERMSIG(status), argv[0]);
} else {
+ handle_initial_delay();
while (!done) {
nanosleep(&ts, NULL);
if (interval)
@@ -924,7 +944,7 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
static void print_aggr(char *prefix)
{
struct perf_evsel *counter;
- int cpu, s, s2, id, nr;
+ int cpu, cpu2, s, s2, id, nr;
u64 ena, run, val;
if (!(aggr_map || aggr_get_id))
@@ -936,7 +956,8 @@ static void print_aggr(char *prefix)
val = ena = run = 0;
nr = 0;
for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
- s2 = aggr_get_id(evsel_list->cpus, cpu);
+ cpu2 = perf_evsel__cpus(counter)->map[cpu];
+ s2 = aggr_get_id(evsel_list->cpus, cpu2);
if (s2 != id)
continue;
val += counter->counts->cpu[cpu].val;
@@ -948,7 +969,7 @@ static void print_aggr(char *prefix)
fprintf(output, "%s", prefix);
if (run == 0 || ena == 0) {
- aggr_printout(counter, cpu, nr);
+ aggr_printout(counter, id, nr);
fprintf(output, "%*s%s%*s",
csv_output ? 0 : 18,
@@ -1148,13 +1169,34 @@ static void skip_signal(int signo)
done = 1;
signr = signo;
+ /*
+ * render child_pid harmless
+ * won't send SIGTERM to a random
+ * process in case of race condition
+ * and fast PID recycling
+ */
+ child_pid = -1;
}
static void sig_atexit(void)
{
+ sigset_t set, oset;
+
+ /*
+ * avoid race condition with SIGCHLD handler
+ * in skip_signal() which is modifying child_pid
+ * goal is to avoid send SIGTERM to a random
+ * process
+ */
+ sigemptyset(&set);
+ sigaddset(&set, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &set, &oset);
+
if (child_pid != -1)
kill(child_pid, SIGTERM);
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+
if (signr == -1)
return;
@@ -1397,6 +1439,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
"aggregate counts per processor socket", AGGR_SOCKET),
OPT_SET_UINT(0, "per-core", &aggr_mode,
"aggregate counts per physical processor core", AGGR_CORE),
+ OPT_UINTEGER('D', "delay", &initial_delay,
+ "ms to wait before starting measurement after program start"),
OPT_END()
};
const char * const stat_usage[] = {