diff options
| author | Dapeng Mi <dapeng1.mi@linux.intel.com> | 2025-04-15 13:41:34 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-04-17 15:19:07 +0300 |
| commit | a5f5e1238f4ff919816f69e77d2537a48911767b (patch) | |
| tree | 7d2b3929f9bda5f2c30ecbc9b454a8134418d2cf | |
| parent | 506f981ab40f0b03a11a640cfd77f48b09aff330 (diff) | |
| download | linux-a5f5e1238f4ff919816f69e77d2537a48911767b.tar.xz | |
perf/x86/intel: Don't clear perf metrics overflow bit unconditionally
The below code would always unconditionally clear other status bits like
perf metrics overflow bit once PEBS buffer overflows:
status &= intel_ctrl | GLOBAL_STATUS_TRACE_TOPAPMI;
This is incorrect. Perf metrics overflow bit should be cleared only when
fixed counter 3 in PEBS counter group. Otherwise perf metrics overflow
could be missed to handle.
Closes: https://lore.kernel.org/all/20250225110012.GK31462@noisy.programming.kicks-ass.net/
Fixes: 7b2c05a15d29 ("perf/x86/intel: Generic support for hardware TopDown metrics")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250415104135.318169-1-dapeng1.mi@linux.intel.com
| -rw-r--r-- | arch/x86/events/intel/core.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 09d2d66c9f21..2b70a3adde2f 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3049,7 +3049,6 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); int bit; int handled = 0; - u64 intel_ctrl = hybrid(cpuc->pmu, intel_ctrl); inc_irq_stat(apic_perf_irqs); @@ -3093,7 +3092,6 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) handled++; x86_pmu_handle_guest_pebs(regs, &data); static_call(x86_pmu_drain_pebs)(regs, &data); - status &= intel_ctrl | GLOBAL_STATUS_TRACE_TOPAPMI; /* * PMI throttle may be triggered, which stops the PEBS event. @@ -3104,6 +3102,15 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) */ if (pebs_enabled != cpuc->pebs_enabled) wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled); + + /* + * Above PEBS handler (PEBS counters snapshotting) has updated fixed + * counter 3 and perf metrics counts if they are in counter group, + * unnecessary to update again. + */ + if (cpuc->events[INTEL_PMC_IDX_FIXED_SLOTS] && + is_pebs_counter_event_group(cpuc->events[INTEL_PMC_IDX_FIXED_SLOTS])) + status &= ~GLOBAL_STATUS_PERF_METRICS_OVF_BIT; } /* @@ -3123,6 +3130,8 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) static_call(intel_pmu_update_topdown_event)(NULL, NULL); } + status &= hybrid(cpuc->pmu, intel_ctrl); + /* * Checkpointed counters can lead to 'spurious' PMIs because the * rollback caused by the PMI will have cleared the overflow status |