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

Paul Mackerras
2009-05-25T00:35:06Z

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.

Paul.