Merge "perf: Cancel the mux hrtimer during CPU hotplug to avoid migration"

1 files changed, 14 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 77bbbc18ce1f..66c1084752f9 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9656,13 +9656,26 @@ static void __perf_event_stop_swclock(void *__info)
 
 static void perf_event_exit_cpu_context(int cpu)
 {
+	struct perf_cpu_context *cpuctx;
 	struct perf_event_context *ctx;
+	unsigned long flags;
 	struct pmu *pmu;
 	int idx;
 
 	idx = srcu_read_lock(&pmus_srcu);
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
+		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+		ctx = &cpuctx->ctx;
+
+		/* Cancel the mux hrtimer to avoid CPU migration */
+		if (pmu->task_ctx_nr != perf_sw_context) {
+			raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
+			hrtimer_cancel(&cpuctx->hrtimer);
+			cpuctx->hrtimer_active = 0;
+			raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock,
+							flags);
+		}
+
 		mutex_lock(&ctx->mutex);
 		/*
 		 * If keeping events across hotplugging is supported, do not