Current perf ISR loops thru all 32 counters, checking for each if it caused the interrupt. Instead only loop thru counters which actually interrupted (typically 1).
Signed-off-by: Vineet Gupta <[email protected]> --- arch/arc/kernel/perf_event.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c index 2ce24e74f879..0eaa132a2c90 100644 --- a/arch/arc/kernel/perf_event.c +++ b/arch/arc/kernel/perf_event.c @@ -377,21 +377,22 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev) struct perf_sample_data data; struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu); struct pt_regs *regs; - int active_ints; + unsigned int active_ints; int idx; arc_pmu_disable(&arc_pmu->pmu); active_ints = read_aux_reg(ARC_REG_PCT_INT_ACT); + if (!active_ints) + goto done; regs = get_irq_regs(); - for (idx = 0; idx < arc_pmu->n_counters; idx++) { - struct perf_event *event = pmu_cpu->act_counter[idx]; + do { + struct perf_event *event; struct hw_perf_event *hwc; - if (!(active_ints & (1 << idx))) - continue; + idx = __ffs(active_ints); /* Reset interrupt flag by writing of 1 */ write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx); @@ -404,19 +405,22 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev) write_aux_reg(ARC_REG_PCT_INT_CTRL, read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx)); + event = pmu_cpu->act_counter[idx]; hwc = &event->hw; WARN_ON_ONCE(hwc->idx != idx); arc_perf_event_update(event, &event->hw, event->hw.idx); perf_sample_data_init(&data, 0, hwc->last_period); - if (!arc_pmu_event_set_period(event)) - continue; + if (arc_pmu_event_set_period(event)) { + if (perf_event_overflow(event, &data, regs)) + arc_pmu_stop(event, 0); + } - if (perf_event_overflow(event, &data, regs)) - arc_pmu_stop(event, 0); - } + active_ints &= ~(1U << idx); + } while (active_ints); +done: arc_pmu_enable(&arc_pmu->pmu); return IRQ_HANDLED; -- 2.7.4
