diff options
| -rw-r--r-- | kernel/events/core.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index ee20d4c546b5..d704e23914bf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3211,6 +3211,13 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx, return; perf_ctx_lock(cpuctx, ctx); + /* + * We must check ctx->nr_events while holding ctx->lock, such + * that we serialize against perf_install_in_context(). + */ + if (!ctx->nr_events) + goto unlock; + perf_pmu_disable(ctx->pmu); /* * We want to keep the following priority order: @@ -3224,6 +3231,8 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx, cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); perf_event_sched_in(cpuctx, ctx, task); perf_pmu_enable(ctx->pmu); + +unlock: perf_ctx_unlock(cpuctx, ctx); } |