From 07edf7121374609709ef1b0889f6e7b8d6a62ec1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 22 Mar 2009 23:10:46 +0100 Subject: tracing/events: don't use wake up for events Impact: fix hard-lockup with sched switch events Some ftrace events, such as sched wakeup, can be traced while the runqueue lock is hold. Since they are using trace_current_buffer_unlock_commit(), they call wake_up() which can try to grab the runqueue lock too, resulting in a deadlock. Now for all event, we call a new helper: trace_nowake_buffer_unlock_commit() which do pretty the same than trace_current_buffer_unlock_commit() except than it doesn't call trace_wake_up(). Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <1237759847-21025-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f267723c3c5..54fd9bcd0a6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -483,6 +483,8 @@ trace_current_buffer_lock_reserve(unsigned char type, unsigned long len, unsigned long flags, int pc); void trace_current_buffer_unlock_commit(struct ring_buffer_event *event, unsigned long flags, int pc); +void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event, + unsigned long flags, int pc); struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data); -- cgit v1.2.3