1 files changed, 57 insertions, 32 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 9ecaa45ab6b2..3256e36ad251 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2674,20 +2674,21 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
 static void perf_output_lock(struct perf_output_handle *handle)
 {
         struct perf_mmap_data *data = handle->data;
-        int cpu;
+        int cur, cpu = get_cpu();
 
         handle->locked = 0;
 
-        local_irq_save(handle->flags);
-        cpu = smp_processor_id();
-
-        if (in_nmi() && atomic_read(&data->lock) == cpu)
-                return;
+        for (;;) {
+                cur = atomic_cmpxchg(&data->lock, -1, cpu);
+                if (cur == -1) {
+                        handle->locked = 1;
+                        break;
+                }
+                if (cur == cpu)
+                        break;
 
-        while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
                 cpu_relax();
-
-        handle->locked = 1;
+        }
 }
 
 static void perf_output_unlock(struct perf_output_handle *handle)
@@ -2733,7 +2734,7 @@ again:
         if (atomic_xchg(&data->wakeup, 0))
                 perf_output_wakeup(handle);
 out:
-        local_irq_restore(handle->flags);
+        put_cpu();
 }
 
 void perf_output_copy(struct perf_output_handle *handle,
@@ -3976,8 +3977,9 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
                 regs = task_pt_regs(current);
 
         if (regs) {
-                if (perf_event_overflow(event, 0, &data, regs))
-                        ret = HRTIMER_NORESTART;
+                if (!(event->attr.exclude_idle && current->pid == 0))
+                        if (perf_event_overflow(event, 0, &data, regs))
+                                ret = HRTIMER_NORESTART;
         }
 
         period = max_t(u64, 10000, event->hw.sample_period);
@@ -3986,6 +3988,42 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
         return ret;
 }
 
+static void perf_swevent_start_hrtimer(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        hwc->hrtimer.function = perf_swevent_hrtimer;
+        if (hwc->sample_period) {
+                u64 period;
+
+                if (hwc->remaining) {
+                        if (hwc->remaining < 0)
+                                period = 10000;
+                        else
+                                period = hwc->remaining;
+                        hwc->remaining = 0;
+                } else {
+                        period = max_t(u64, 10000, hwc->sample_period);
+                }
+                __hrtimer_start_range_ns(&hwc->hrtimer,
+                                ns_to_ktime(period), 0,
+                                HRTIMER_MODE_REL, 0);
+        }
+}
+
+static void perf_swevent_cancel_hrtimer(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        if (hwc->sample_period) {
+                ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
+                hwc->remaining = ktime_to_ns(remaining);
+
+                hrtimer_cancel(&hwc->hrtimer);
+        }
+}
+
 /*
  * Software event: cpu wall time clock
  */
@@ -4008,22 +4046,14 @@ static int cpu_clock_perf_event_enable(struct perf_event *event)
         int cpu = raw_smp_processor_id();
 
         atomic64_set(&hwc->prev_count, cpu_clock(cpu));
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swevent_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
+        perf_swevent_start_hrtimer(event);
 
         return 0;
 }
 
 static void cpu_clock_perf_event_disable(struct perf_event *event)
 {
-        if (event->hw.sample_period)
-                hrtimer_cancel(&event->hw.hrtimer);
+        perf_swevent_cancel_hrtimer(event);
         cpu_clock_perf_event_update(event);
 }
 
@@ -4060,22 +4090,15 @@ static int task_clock_perf_event_enable(struct perf_event *event)
         now = event->ctx->time;
 
         atomic64_set(&hwc->prev_count, now);
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swevent_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
+
+        perf_swevent_start_hrtimer(event);
 
         return 0;
 }
 
 static void task_clock_perf_event_disable(struct perf_event *event)
 {
-        if (event->hw.sample_period)
-                hrtimer_cancel(&event->hw.hrtimer);
+        perf_swevent_cancel_hrtimer(event);
         task_clock_perf_event_update(event, event->ctx->time);
 
 }
@@ -4252,6 +4275,8 @@ static const struct pmu *sw_perf_event_init(struct perf_event *event)
         case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
         case PERF_COUNT_SW_CONTEXT_SWITCHES:
         case PERF_COUNT_SW_CPU_MIGRATIONS:
+        case PERF_COUNT_SW_ALIGNMENT_FAULTS:
+        case PERF_COUNT_SW_EMULATION_FAULTS:
                 if (!event->parent) {
                         atomic_inc(&perf_swevent_enabled[event_id]);
                         event->destroy = sw_perf_event_destroy;