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trace_clock: fix preemption bug

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Using the function_graph tracer in recent kernels generates a spew of
preemption BUGs. Fix this by not requiring trace_clock_local() users
to disable preemption themselves.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2009-03-10 19:03:43 +01:00
committed by Ingo Molnar
parent 2395037e5d
commit 6cc3c6e12b
1 changed files with 8 additions and 1 deletions
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9
kernel/trace/trace_clock.c
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@@ -27,12 +27,19 @@
*/ */
u64 notrace trace_clock_local(void) u64 notrace trace_clock_local(void)
{ {
unsigned long flags;
u64 clock;
/* /*
* sched_clock() is an architecture implemented, fast, scalable, * sched_clock() is an architecture implemented, fast, scalable,
* lockless clock. It is not guaranteed to be coherent across * lockless clock. It is not guaranteed to be coherent across
* CPUs, nor across CPU idle events. * CPUs, nor across CPU idle events.
*/ */
return sched_clock(); raw_local_irq_save(flags);
clock = sched_clock();
raw_local_irq_restore(flags);
return clock;
} }
/* /*