Re: [PATCH 2/2] perf_counter: optimize context switch betweenidentical inherited contexts

From: Paul Mackerras
Date: Sun May 24 2009 - 20:35:09 EST

Peter Zijlstra writes:

> Ingo just pointed out that there is nothing there to close the race with
> attaching a counter.
> That is, you could end up attaching your counter to the wrong task.

Good point. Doing the unclone in find_get_context would be a start,
but the locking could get tricky (in fact we don't have any way to
remove an inherited counter from a context, so we only have to worry
about counters being attached). I'll work out a solution after I have
digested your recent batch of patches.

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