Commit 1929def9 authored Sep 12, 2014 by Jiri Olsa Committed by Ingo Molnar Sep 24, 2014

perf: Fix child event initial state setup



Currently we initialize the child event based on the original
parent state. This is wrong, because the original parent event
(and its state) is not related to current fork and also could
be already gone.

We need to initialize the child state based on the immediate
parent event state.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1410520708-19275-2-git-send-email-jolsa@kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent dc633982

kernel/events/core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -7818,6 +7818,7 @@ inherit_event(struct perf_event *parent_event,
		struct perf_event *group_leader,
		struct perf_event_context *child_ctx)
		{
		enum perf_event_active_state parent_state = parent_event->state;
		struct perf_event *child_event;
		unsigned long flags;

		@@ -7851,7 +7852,7 @@ inherit_event(struct perf_event *parent_event,
		* not its attr.disabled bit. We hold the parent's mutex,
		* so we won't race with perf_event_{en, dis}able_family.
		*/
		if (parent_event->state >= PERF_EVENT_STATE_INACTIVE)
		if (parent_state >= PERF_EVENT_STATE_INACTIVE)
		child_event->state = PERF_EVENT_STATE_INACTIVE;
		else
		child_event->state = PERF_EVENT_STATE_OFF;