From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu
Subject: Re: [PATCH] perf_event: fix loss of notification with multi-event sampling
Date: Wed, 23 Nov 2011 11:36:46 +0100 [thread overview]
Message-ID: <1322044606.14799.26.camel@twins> (raw)
In-Reply-To: <CABPqkBRE6bH8WV1ZMeUKrEuF3D4M8WymxzkZOOjsnbya-cOSYg@mail.gmail.com>
On Wed, 2011-11-23 at 11:10 +0100, Stephane Eranian wrote:
> On Wed, Nov 23, 2011 at 11:06 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Wed, 2011-11-23 at 10:30 +0100, Stephane Eranian wrote:
> >>
> >> In the case of perf_event, we are not in a producer-consumer model, so
> >> it seems like the behavior we have now is correct. The caller of poll()
> >> gets stuck if the file descriptor is closed.
> >
> > But wouldn't out event->waitq still be referenced by that waiting task?
> > Even though we freed it in our fops->release() callback?
> >
> I suspect you don't end up in fops->release() if you have an ongoing poll
> because you've probably increment the file's refcount along the way.
You're quite right, poll does that internally. Ok, so we don't need to
worry about this bit then.
prev parent reply other threads:[~2011-11-23 10:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-16 14:53 [PATCH] perf_event: fix loss of notification with multi-event sampling Stephane Eranian
2011-11-22 10:40 ` Peter Zijlstra
2011-11-22 13:15 ` Stephane Eranian
2011-11-22 13:29 ` Peter Zijlstra
2011-11-22 14:13 ` Stephane Eranian
2011-11-22 14:28 ` Stephane Eranian
2011-11-22 21:15 ` Peter Zijlstra
2011-11-23 9:30 ` Stephane Eranian
2011-11-23 10:06 ` Peter Zijlstra
2011-11-23 10:10 ` Stephane Eranian
2011-11-23 10:36 ` Peter Zijlstra [this message]
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