perf_counter: add comment to barrier

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We need to ensure the enabled=0 write happens before we
start disabling the actual counters, so that a pcm_amd_enable()
will not enable one underneath us.

I think the race is impossible anyway, we always balance the
ops within any one context and perform enable() with IRQs disabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

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Peter Zijlstra 2009-03-13 12:21:30 +01:00 • committed by Ingo Molnar

parent 755642322a

commit 60b3df9c1e

1 changed files with 4 additions and 0 deletions

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arch/x86/kernel/cpu/perf_counter.c

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