Messages in this thread | | | Date | Tue, 25 Jan 2022 20:12:58 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 1/1] perf/core: Wake up parent event if inherited event has no ring buffer |
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On Mon, Jan 24, 2022 at 02:58:18PM +0000, James Clark wrote:
> > Would this be the better patch? > > Yes I tested this and it also works.
Excellent!
> There is one other suspicious access > of ->rb followed by if(rb) here in perf_poll(), but maybe it works out ok? > > mutex_lock(&event->mmap_mutex); > rb = event->rb; > if (rb) > events = atomic_xchg(&rb->poll, 0); >
That case must be good since it is the event from a file. Those cannot be clones.
> We also have a Perf self test that covers this failure for Arm SPE now, I'm not > sure if I should post that separately or with your new version of this fix?
They'd be routed through separate trees anyway, Arnaldo takes the userspace stuff.
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