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From: Peter Zijlstra <peterz@infradead.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Константин Михайлов" <mikhaylovkonstantin100@gmail.com>,
	"Mark Rutland" <mark.rutland@arm.com>,
	linux-kernel@vger.kernel.org
Subject: Re: perf AUX: race causes poll() hang
Date: Tue, 19 May 2026 11:11:36 +0200	[thread overview]
Message-ID: <20260519091136.GA3102624@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <b6b13eb7-b407-4429-9f22-1c85d84dff1c@intel.com>

On Tue, May 19, 2026 at 08:58:52AM +0300, Adrian Hunter wrote:

> > @@ -7612,10 +7620,8 @@ static void __perf_pending_disable(struct perf_event *event)
> >  	 * Yay, we hit home and are in the context of the event.
> >  	 */
> >  	if (cpu == smp_processor_id()) {
> > -		if (event->pending_disable) {
> > -			event->pending_disable = 0;
> > +		if (event->pending_disable)
> 
> At this point, can _perf_event_enable() on another CPU decide
> to do nothing ("Already running, nothing to do"), but then the
> disable below contradicts that?

Should be serialized on ctx->lock IIRC

> >  			perf_event_disable_local(event);
> > -		}
> >  		return;
> >  	}
> >  
> 

  reply	other threads:[~2026-05-19  9:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAE7+JAnhZSuMMG9+0pZ2G6ZBR-OAC1hHptkr=T=x5LK9n19vOQ@mail.gmail.com>
2026-05-18  9:41 ` Peter Zijlstra
2026-05-19  5:58   ` Adrian Hunter
2026-05-19  9:11     ` Peter Zijlstra [this message]
2026-06-14 22:40   ` Konstantin Mikhaylov

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