Ensure all threads are started and ready before we enable events. Using pthread_cond_t signaling logic for that.
Link: http://lkml.kernel.org/n/tip-z4x5ikp8v7e3flpxoo4bv...@git.kernel.org Signed-off-by: Jiri Olsa <jo...@kernel.org> --- tools/perf/builtin-record.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 6ad57ba6657e..fbca1d15b90d 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -102,6 +102,9 @@ struct record { unsigned long long samples; struct record_thread *threads; int threads_cnt; + int threads_signal_cnt; + pthread_mutex_t threads_signal_mutex; + pthread_cond_t threads_signal_cond; unsigned long waking; }; @@ -1145,6 +1148,9 @@ record__threads_config(struct record *rec) ret = record__threads_create_poll(rec); + pthread_mutex_init(&rec->threads_signal_mutex, NULL); + pthread_cond_init(&rec->threads_signal_cond, NULL); + out: if (ret) record__threads_clean(rec); @@ -1181,6 +1187,26 @@ record_thread__process(struct record *rec) return NULL; } +static void signal_main(struct record *rec) +{ + pthread_mutex_lock(&rec->threads_signal_mutex); + rec->threads_signal_cnt++; + pthread_cond_signal(&rec->threads_signal_cond); + pthread_mutex_unlock(&rec->threads_signal_mutex); +} + +static void wait_for_signal(struct record *rec) +{ + pthread_mutex_lock(&rec->threads_signal_mutex); + + while (rec->threads_signal_cnt < rec->threads_cnt) { + pthread_cond_wait(&rec->threads_signal_cond, + &rec->threads_signal_mutex); + } + + pthread_mutex_unlock(&rec->threads_signal_mutex); +} + static void *worker(void *arg) { struct record_thread *th = arg; @@ -1189,6 +1215,8 @@ static void *worker(void *arg) thread = th; thread->state = RECORD_THREAD__RUNNING; + signal_main(rec); + return record_thread__process(rec); } @@ -1197,12 +1225,17 @@ static int record__threads_start(struct record *rec) struct record_thread *threads = rec->threads; int i, err = 0; + rec->threads_signal_cnt = 1; + for (i = 1; !err && i < rec->threads_cnt; i++) { struct record_thread *th = threads + i; err = pthread_create(&th->pt, NULL, worker, th); } + if (rec->threads_cnt > 1) + wait_for_signal(rec); + return err; } -- 2.17.1
