diff options
Diffstat (limited to 'drivers/perf/arm_pmuv3.c')
| -rw-r--r-- | drivers/perf/arm_pmuv3.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 69c5cc8f5606..d1d6000517b2 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -981,6 +981,7 @@ static int armv8pmu_get_chain_idx(struct pmu_hw_events *cpuc, static bool armv8pmu_can_use_pmccntr(struct pmu_hw_events *cpuc, struct perf_event *event) { + struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; unsigned long evtype = hwc->config_base & ARMV8_PMU_EVTYPE_EVENT; @@ -1001,6 +1002,15 @@ static bool armv8pmu_can_use_pmccntr(struct pmu_hw_events *cpuc, if (has_branch_stack(event)) return false; + /* + * The PMCCNTR_EL0 increments from the processor clock rather than + * the PE clock (ARM DDI0487 L.b D13.1.3) which means it'll continue + * counting on a WFI PE if one of its SMT sibling is not idle on a + * multi-threaded implementation. So don't use it on SMT cores. + */ + if (cpu_pmu->has_smt) + return false; + return true; } |