From 1e5de7d9c6ded0722736eb6e58c72b18937efc06 Mon Sep 17 00:00:00 2001 From: Alexey Bayduraev Date: Mon, 17 Jan 2022 21:34:26 +0300 Subject: [PATCH] perf record: Stop threads in the end of trace streaming Signal thread to terminate by closing write fd of msg pipe. Receive THREAD_MSG__READY message as the confirmation of the thread's termination. Stop threads created for parallel trace streaming prior their stats processing. Reviewed-by: Riccardo Mancini Signed-off-by: Alexey Bayduraev Tested-by: Jiri Olsa Tested-by: Riccardo Mancini Acked-by: Andi Kleen Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Antonov Cc: Alexander Shishkin Cc: Alexei Budankov Cc: Ingo Molnar Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/55ef8cc5ec3a96360660d9dc1763573225325f8c.1642440724.git.alexey.v.bayduraev@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 163d261..0e65b80 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -114,6 +114,16 @@ struct record_thread { static __thread struct record_thread *thread; +enum thread_msg { + THREAD_MSG__UNDEFINED = 0, + THREAD_MSG__READY, + THREAD_MSG__MAX, +}; + +static const char *thread_msg_tags[THREAD_MSG__MAX] = { + "UNDEFINED", "READY" +}; + struct record { struct perf_tool tool; struct record_opts opts; @@ -1886,6 +1896,24 @@ static void record__uniquify_name(struct record *rec) } } +static int record__terminate_thread(struct record_thread *thread_data) +{ + int err; + enum thread_msg ack = THREAD_MSG__UNDEFINED; + pid_t tid = thread_data->tid; + + close(thread_data->pipes.msg[1]); + thread_data->pipes.msg[1] = -1; + err = read(thread_data->pipes.ack[0], &ack, sizeof(ack)); + if (err > 0) + pr_debug2("threads[%d]: sent %s\n", tid, thread_msg_tags[ack]); + else + pr_warning("threads[%d]: failed to receive termination notification from %d\n", + thread->tid, tid); + + return 0; +} + static int record__start_threads(struct record *rec) { struct record_thread *thread_data = rec->thread_data; @@ -1902,6 +1930,9 @@ static int record__stop_threads(struct record *rec) int t; struct record_thread *thread_data = rec->thread_data; + for (t = 1; t < rec->nr_threads; t++) + record__terminate_thread(&thread_data[t]); + for (t = 0; t < rec->nr_threads; t++) rec->samples += thread_data[t].samples; -- 2.7.4