Messages in this thread Patch in this message | | | Date | Mon, 20 Apr 2009 18:22:59 -0400 | From | Steven Rostedt <> | Subject | [PATCH 2/2] tracing: use nowakeup version of commit for function event trace tests |
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From: Steven Rostedt <srostedt@redhat.com>
The startup tests for the event tracer also runs with the function tracer enabled. The "wakeup" version of the trace commit was used which can grab spinlocks. If a task was preempted by an NMI that called a function being traced, it could deadlock due to the function tracer trying to grab the same lock.
Thanks to Frederic Weisbecker for pointing out where the bug was.
Reported-by: Ingo Molnar <mingo@elte.hu> Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/trace/trace_events.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 98daf5d..672b195 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1164,7 +1164,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip) entry->ip = ip; entry->parent_ip = parent_ip; - trace_current_buffer_unlock_commit(event, flags, pc); + trace_nowake_buffer_unlock_commit(event, flags, pc); out: atomic_dec(&per_cpu(test_event_disable, cpu)); -- 1.6.2.1 --
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