perf: Fix time locking

[safe/jmp/linux-2.6] / kernel / perf_event.c

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index e66f6c4..fdfae88 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1061,8 +1061,6 @@ static int context_equiv(struct perf_event_context *ctx1,
                && !ctx1->pin_count && !ctx2->pin_count;
 }
 
-static void __perf_event_read(void *event);
-
 static void __perf_event_sync_stat(struct perf_event *event,
                                     struct perf_event *next_event)
 {
@@ -1080,8 +1078,8 @@ static void __perf_event_sync_stat(struct perf_event *event,
         */
        switch (event->state) {
        case PERF_EVENT_STATE_ACTIVE:
-               __perf_event_read(event);
-               break;
+               event->pmu->read(event);
+               /* fall-through */
 
        case PERF_EVENT_STATE_INACTIVE:
                update_event_times(event);
@@ -1528,10 +1526,12 @@ static void __perf_event_read(void *info)
        if (ctx->task && cpuctx->task_ctx != ctx)
                return;
 
-       if (ctx->is_active)
-               update_context_time(ctx);
-       event->pmu->read(event);
+       spin_lock(&ctx->lock);
+       update_context_time(ctx);
        update_event_times(event);
+       spin_unlock(&ctx->lock);
+
+       event->pmu->read(event);
 }
 
 static u64 perf_event_read(struct perf_event *event)
@@ -1544,7 +1544,13 @@ static u64 perf_event_read(struct perf_event *event)
                smp_call_function_single(event->oncpu,
                                         __perf_event_read, event, 1);
        } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
+               struct perf_event_context *ctx = event->ctx;
+               unsigned long flags;
+
+               spin_lock_irqsave(&ctx->lock, flags);
+               update_context_time(ctx);
                update_event_times(event);
+               spin_unlock_irqrestore(&ctx->lock, flags);
        }
 
        return atomic64_read(&event->count);