Re: [PATCH V2 0/5] Several fixes for group flag and counters-snapshotting

[Peter Zijlstra <peterz@infradead.org>]

On Thu, Apr 24, 2025 at 12:00:02PM -0400, Liang, Kan wrote:
> 
> 
> On 2025-04-24 10:25 a.m., Peter Zijlstra wrote:
> > On Thu, Apr 24, 2025 at 06:47:13AM -0700, kan.liang@linux.intel.com wrote:
> >> From: Kan Liang <kan.liang@linux.intel.com>
> >>
> >> The patch series includes several fixes for the new Intel features.
> >>
> >> The first 4 patches are to fix the group flag issue which impacts the
> >> branch counters, PEBS counters-snapshotting and ACR.
> >> The V1 can be found at
> >> https://lore.kernel.org/lkml/20250423221015.268949-1-kan.liang@linux.intel.com/
> >>
> >> The last patch is to fix an issue of counters-snapshotting.
> >> The V1 can be found at
> >> https://lore.kernel.org/lkml/20250204210514.4089680-1-kan.liang@linux.intel.com/
> >>
> >> Kan Liang (5):
> >>   perf/x86/intel: Only check the group flag for X86 leader
> >>   perf/x86/intel: Check the X86 leader for pebs_counter_event_group
> >>   perf/x86/intel: Check the X86 leader for ACR group
> >>   perf/x86: Optimize the is_x86_event
> >>   perf/x86/intel/ds: Fix counter backwards of non-precise events
> >>     counters-snapshotting
> > 
> > It didn't apply cleanly,
> 
> Sorry for it.
> 
> > but I stomped on it and pushed out new
> > perf/urgent and perf/core branches that contain these patches. Hopefully
> > I didn't mess it up ;-)
> 
> Something is missed in this patch 5d4d71ebc737 ("perf/x86/intel: Only
> check the group flag for X86 leader")
> 
> diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
> index a73b1ff031b2..1f72a4f77b5c 100644
> --- a/arch/x86/events/perf_event.h
> +++ b/arch/x86/events/perf_event.h
> @@ -119,7 +119,7 @@ static inline bool check_leader_group(struct
> perf_event *leader, int flags)
> 
>  static inline bool is_branch_counters_group(struct perf_event *event)
>  {
> -	return check_leader_group(event->group_leader, PERF_X86_EVENT_PEBS_CNTR);
> +	return check_leader_group(event->group_leader,
> PERF_X86_EVENT_BRANCH_COUNTERS);
>  }
> 
>  static inline bool is_pebs_counter_event_group(struct perf_event *event)

Right.

> @@ -1123,7 +1123,6 @@ static struct perf_pmu_format_hybrid_attr
> format_attr_hybrid_##_name = {\
>  	.pmu_type	= _pmu,                                         \
>  }
> 
> -int is_x86_event(struct perf_event *event);
>  struct pmu *x86_get_pmu(unsigned int cpu);
>  extern struct x86_pmu x86_pmu __read_mostly;

See, that isn't there in tip/perf/urgent :-)


I've pushed out an updated set. Please check.