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

[Dapeng Mi]

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/20260706022123.480411F000E9@xxxxxxxxxxxxxxx/
https://lore.kernel.org/all/20260706021852.DE2ED1F000E9@xxxxxxxxxxxxxxx/

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/20260713082734.3162099-1-dapeng1.mi@xxxxxxxxxxxxxxx/ 
v1: https://lore.kernel.org/all/20260710065128.1799838-1-dapeng1.mi@xxxxxxxxxxxxxxx/

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
-- 
2.34.1