On Tue, Nov 24, 2020 at 5:10 PM Peter Zijlstra <pet...@infradead.org> wrote:
>
> On Tue, Nov 24, 2020 at 02:01:39PM +0900, Namhyung Kim wrote:
>
> > Yes, it's not about __intel_pmu_pebs_event(). I'm looking at
> > intel_pmu_drain_pebs_nhm() specifically. There's code like
> >
> > /* log dropped samples number */
> > if (error[bit]) {
> > perf_log_lost_samples(event, error[bit]);
> >
> > if (perf_event_account_interrupt(event))
> > x86_pmu_stop(event, 0);
> > }
> >
> > if (counts[bit]) {
> > __intel_pmu_pebs_event(event, iregs, base,
> > top, bit, counts[bit],
> > setup_pebs_fixed_sample_data);
> > }
> >
> > There's a path to x86_pmu_stop() when an error bit is on.
>
> That would seem to suggest you try something like this:
>
> diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
> index 31b9e58b03fe..8c6ee8be8b6e 100644
> --- a/arch/x86/events/intel/ds.c
> +++ b/arch/x86/events/intel/ds.c
> @@ -1945,7 +1945,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs
> *iregs, struct perf_sample_d
> if (error[bit]) {
> perf_log_lost_samples(event, error[bit]);
>
> - if (perf_event_account_interrupt(event))
> + if (iregs && perf_event_account_interrupt(event))
> x86_pmu_stop(event, 0);
> }
>
That would work too and much simpler!
Thanks,
Namhyung
