diff options
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 4a86a0133ac3..9b536be74f7b 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -11,6 +11,7 @@ */ #define pr_fmt(fmt) "hw perfevents: " fmt +#include <linux/cpumask.h> #include <linux/kernel.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> @@ -229,6 +230,10 @@ armpmu_add(struct perf_event *event, int flags) int idx; int err = 0; + /* An event following a process won't be stopped earlier */ + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return -ENOENT; + perf_pmu_disable(event->pmu); /* If we don't have a space for the counter then finish early. */ @@ -454,6 +459,17 @@ static int armpmu_event_init(struct perf_event *event) int err = 0; atomic_t *active_events = &armpmu->active_events; + /* + * Reject CPU-affine events for CPUs that are of a different class to + * that which this PMU handles. Process-following events (where + * event->cpu == -1) can be migrated between CPUs, and thus we have to + * reject them later (in armpmu_add) if they're scheduled on a + * different class of CPU. + */ + if (event->cpu != -1 && + !cpumask_test_cpu(event->cpu, &armpmu->supported_cpus)) + return -ENOENT; + /* does not support taken branch sampling */ if (has_branch_stack(event)) return -EOPNOTSUPP; @@ -489,6 +505,10 @@ static void armpmu_enable(struct pmu *pmu) struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); + /* For task-bound events we may be called on other CPUs */ + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return; + if (enabled) armpmu->start(armpmu); } @@ -496,6 +516,11 @@ static void armpmu_enable(struct pmu *pmu) static void armpmu_disable(struct pmu *pmu) { struct arm_pmu *armpmu = to_arm_pmu(pmu); + + /* For task-bound events we may be called on other CPUs */ + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return; + armpmu->stop(armpmu); } |