From 4c09bafae37d870ab8efc50faeeb4855cb55b5b7 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 8 Aug 2011 23:03:34 +0200 Subject: [PATCH] perf sched: Do not delete session object prematurely The session object is released prematurely when processing events for latency command. The session's thread objects are used within the output_lat_thread function. Runnning following commands: # perf sched record # perf sched latency the latter displays incorrect data and might cause access violation. Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1312837414-3819-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-sched.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index dcfe887..3d5702c 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -1637,23 +1637,29 @@ static struct perf_event_ops event_ops = { .ordered_samples = true, }; -static int read_events(void) +static void read_events(bool destroy, struct perf_session **psession) { int err = -EINVAL; struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0, false, &event_ops); if (session == NULL) - return -ENOMEM; + die("No Memory"); if (perf_session__has_traces(session, "record -R")) { err = perf_session__process_events(session, &event_ops); + if (err) + die("Failed to process events, error %d", err); + nr_events = session->hists.stats.nr_events[0]; nr_lost_events = session->hists.stats.total_lost; nr_lost_chunks = session->hists.stats.nr_events[PERF_RECORD_LOST]; } - perf_session__delete(session); - return err; + if (destroy) + perf_session__delete(session); + + if (psession) + *psession = session; } static void print_bad_events(void) @@ -1689,9 +1695,10 @@ static void print_bad_events(void) static void __cmd_lat(void) { struct rb_node *next; + struct perf_session *session; setup_pager(); - read_events(); + read_events(false, &session); sort_lat(); printf("\n ---------------------------------------------------------------------------------------------------------------\n"); @@ -1717,6 +1724,7 @@ static void __cmd_lat(void) print_bad_events(); printf("\n"); + perf_session__delete(session); } static struct trace_sched_handler map_ops = { @@ -1731,7 +1739,7 @@ static void __cmd_map(void) max_cpu = sysconf(_SC_NPROCESSORS_CONF); setup_pager(); - read_events(); + read_events(true, NULL); print_bad_events(); } @@ -1744,7 +1752,7 @@ static void __cmd_replay(void) test_calibrations(); - read_events(); + read_events(true, NULL); printf("nr_run_events: %ld\n", nr_run_events); printf("nr_sleep_events: %ld\n", nr_sleep_events); -- 2.7.4