Re: [Patch v3 0/8] perf/x86: Miscellaneous PMU bug fixes and optimizations

Peter,

Kindly ping. Could you please review this bug fixing patch series? The
changes in this series suppose to be low risky. 

This series is a preceding patchset of the "Support SIMD/eGPRs/SSP
registers sampling for perf" patch series.
https://lore.kernel.org/all/[email protected]/

Thanks.

On 7/17/2026 4:03 PM, Dapeng Mi wrote:
> Changes since v2:
> - Patch 6/8: Fix the typo in comments (Thomas).
> - Patch 8/8: New patch which prevents drain_pebs() reentry.
>
> Changes since v1:
> - Patch 3/7: Ensure cpuc->pmu is not the static pmu before calling
>   hybrid_pmu(cpuc->pmu) in intel_pmu_cpu_dead() (Sashiko).
>
> This series fixes recently found x86 core PMU bugs. Most of bugs are
> found by Sashiko in reviewing the "Support SIMD/eGPRs/SSP registers 
> sampling for perf" patch-set, e.g.,
> https://lore.kernel.org/all/[email protected]/
> https://lore.kernel.org/all/[email protected]/
>
> The patch 7/8 optimizes ACR handling in match_prev_assignment() and
> mitigate the performance overhead.
>
> The patch 8/8 enhances intel_pmu_drain_pebs_buffer() to prevent
> drain_pebs() reentry.
>
> Tests:
> Below test cases are run on Diamonds and Novalake. No issues are found.
> - Perf stat test
>   $ perf test 119
> - Perf record tests 
>   $ perf test 155
> - Perf record LBR tests
>   $ perf test 156
>
> History:
> v2: https://lore.kernel.org/all/[email protected]/ 
> v1: https://lore.kernel.org/all/[email protected]/
>
> Dapeng Mi (8):
>   perf/x86: Unregister PMI handler on PMU init failure
>   perf/x86: Free hybrid state on PMU init failure
>   perf/x86: Guard intel_pmu_cpu_dead() against invalid hybrid PMU casts
>   perf/x86/intel: Unwind cpuc state if PEBS buffer setup fails
>   perf/x86: Remove stale fixed counter helper and fix hybrid PMU access
>   perf/x86/intel: Fix intel_cap handling on hybrid PMUs
>   perf/x86: Optimize ACR handling in match_prev_assignment()
>   perf/x86/intel: Prevent drain_pebs() reentry
>
>  arch/x86/events/core.c       |  45 ++++++++++++----
>  arch/x86/events/intel/core.c | 101 ++++++++++++++++++++++++++---------
>  arch/x86/events/intel/ds.c   |   7 ---
>  arch/x86/events/perf_event.h |  12 ++---
>  4 files changed, 113 insertions(+), 52 deletions(-)
>
>
> base-commit: edda9051e267b7390c7ce24b1b71434414ad156e