Re: [PATCH 2/3] perf: arm_spe: Suppress redundant ITRACE start records

[Leo Yan <leo.yan@arm.com>]

On Tue, Sep 01, 2026 at 04:47:04PM +0000, sashiko-bot@kernel.org wrote:

[...]

> > @@ -890,6 +890,8 @@ static void arm_spe_pmu_start(struct perf_event *event, int flags)
> >  		return;
> >  	}
> >  
> > +	perf_event_itrace_started(event);
> > +
> 
> [Severity: Medium]
> Does this correctly suppress redundant records for inherited events?
> 
> The core event scheduling path in perf_log_itrace_start() internally resolves
> to event->parent before checking for the PERF_ATTACH_ITRACE flag. 
> 
> Since perf_event_itrace_started() only mutates the local child event's
> attach_state, the parent event's flag remains permanently unset. 
> 
> Won't this cause the perf core to continue emitting redundant ITRACE_START
> records on every subsequent schedule-in for inherited events, negating the
> intended fix?

This would be an issue in the event core layer and should be addressed
separately. I will send a separate patch to fix it.