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authorVineet Gupta <vgupta@synopsys.com>2015-05-09 18:27:30 +0530
committerVineet Gupta <vgupta@synopsys.com>2017-11-21 15:20:31 -0800
commit4d431290402c8d867af7ba45ee75407d68748c4a (patch)
tree5105c19adb9b0834c359706f0a41b1a96b34fda2 /arch
parentff64d695f92123f7d341473921a46add51a44a87 (diff)
downloadlinux-4d431290402c8d867af7ba45ee75407d68748c4a.tar.bz2
ARCv2: perf: tweak overflow interrupt
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). Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arc/kernel/perf_event.c24
1 files 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;