Re: perf AUX: race causes poll() hang

[Peter Zijlstra]

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;
> >  	}
> >  
>