From 63342411efd2d9350ad405205da036cd45ed1640 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 5 May 2014 11:49:16 +0200 Subject: [PATCH] perf: Validate locking assumption Document and validate the locking assumption of event_sched_in(). Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Cc: Paul Mackerras Cc: Vince Weaver Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-sybq1publ9xt5no77cwvi0eo@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 819ffc006d67..0de199729f04 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1678,6 +1678,8 @@ event_sched_in(struct perf_event *event, u64 tstamp = perf_event_time(event); int ret = 0; + lockdep_assert_held(&ctx->lock); + if (event->state <= PERF_EVENT_STATE_OFF) return 0;