diff options
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index e34934f63a4..557e128e4df 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -116,8 +116,14 @@ int armpmu_event_set_period(struct perf_event *event) ret = 1; } - if (left > (s64)armpmu->max_period) - left = armpmu->max_period; + /* + * Limit the maximum period to prevent the counter value + * from overtaking the one we are about to program. In + * effect we are reducing max_period to account for + * interrupt latency (and we are being very conservative). + */ + if (left > (armpmu->max_period >> 1)) + left = armpmu->max_period >> 1; local64_set(&hwc->prev_count, (u64)-left); @@ -484,7 +490,7 @@ static void armpmu_disable(struct pmu *pmu) armpmu->stop(armpmu); } -#ifdef CONFIG_PM_RUNTIME +#ifdef CONFIG_PM static int armpmu_runtime_resume(struct device *dev) { struct arm_pmu_platdata *plat = dev_get_platdata(dev); |