diff options
| -rw-r--r-- | arch/arm/include/asm/pmu.h | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event.c | 22 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event_v6.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event_v7.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/perf_event_xscale.c | 4 |
5 files changed, 16 insertions, 16 deletions
diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index b5a5be2536c1..90114faa9f3c 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -134,7 +134,7 @@ int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type); u64 armpmu_event_update(struct perf_event *event, struct hw_perf_event *hwc, - int idx, int overflow); + int idx); int armpmu_event_set_period(struct perf_event *event, struct hw_perf_event *hwc, diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 5bb91bf3d47f..56173ae16448 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -180,7 +180,7 @@ armpmu_event_set_period(struct perf_event *event, u64 armpmu_event_update(struct perf_event *event, struct hw_perf_event *hwc, - int idx, int overflow) + int idx) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); u64 delta, prev_raw_count, new_raw_count; @@ -193,13 +193,7 @@ again: new_raw_count) != prev_raw_count) goto again; - new_raw_count &= armpmu->max_period; - prev_raw_count &= armpmu->max_period; - - if (overflow) - delta = armpmu->max_period - prev_raw_count + new_raw_count + 1; - else - delta = new_raw_count - prev_raw_count; + delta = (new_raw_count - prev_raw_count) & armpmu->max_period; local64_add(delta, &event->count); local64_sub(delta, &hwc->period_left); @@ -216,7 +210,7 @@ armpmu_read(struct perf_event *event) if (hwc->idx < 0) return; - armpmu_event_update(event, hwc, hwc->idx, 0); + armpmu_event_update(event, hwc, hwc->idx); } static void @@ -232,7 +226,7 @@ armpmu_stop(struct perf_event *event, int flags) if (!(hwc->state & PERF_HES_STOPPED)) { armpmu->disable(hwc, hwc->idx); barrier(); /* why? */ - armpmu_event_update(event, hwc, hwc->idx, 0); + armpmu_event_update(event, hwc, hwc->idx); hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; } } @@ -518,7 +512,13 @@ __hw_perf_event_init(struct perf_event *event) hwc->config_base |= (unsigned long)mapping; if (!hwc->sample_period) { - hwc->sample_period = armpmu->max_period; + /* + * For non-sampling runs, limit the sample_period to half + * of the counter width. That way, the new counter value + * is far less likely to overtake the previous one unless + * you have some serious IRQ latency issues. + */ + hwc->sample_period = armpmu->max_period >> 1; hwc->last_period = hwc->sample_period; local64_set(&hwc->period_left, hwc->sample_period); } diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c index 533be9930ec2..88bf15253fbd 100644 --- a/arch/arm/kernel/perf_event_v6.c +++ b/arch/arm/kernel/perf_event_v6.c @@ -524,7 +524,7 @@ armv6pmu_handle_irq(int irq_num, continue; hwc = &event->hw; - armpmu_event_update(event, hwc, idx, 1); + armpmu_event_update(event, hwc, idx); data.period = event->hw.last_period; if (!armpmu_event_set_period(event, hwc, idx)) continue; diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index 6933244c68f9..6f488610f8fc 100644 --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -963,7 +963,7 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev) continue; hwc = &event->hw; - armpmu_event_update(event, hwc, idx, 1); + armpmu_event_update(event, hwc, idx); data.period = event->hw.last_period; if (!armpmu_event_set_period(event, hwc, idx)) continue; diff --git a/arch/arm/kernel/perf_event_xscale.c b/arch/arm/kernel/perf_event_xscale.c index 3b99d8269829..831e019b017c 100644 --- a/arch/arm/kernel/perf_event_xscale.c +++ b/arch/arm/kernel/perf_event_xscale.c @@ -259,7 +259,7 @@ xscale1pmu_handle_irq(int irq_num, void *dev) continue; hwc = &event->hw; - armpmu_event_update(event, hwc, idx, 1); + armpmu_event_update(event, hwc, idx); data.period = event->hw.last_period; if (!armpmu_event_set_period(event, hwc, idx)) continue; @@ -596,7 +596,7 @@ xscale2pmu_handle_irq(int irq_num, void *dev) continue; hwc = &event->hw; - armpmu_event_update(event, hwc, idx, 1); + armpmu_event_update(event, hwc, idx); data.period = event->hw.last_period; if (!armpmu_event_set_period(event, hwc, idx)) continue; |