Commit faf8f418 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'perf_urgent_for_v6.3_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull perf fixes from Borislav Petkov:

 - Fix "same task" check when redirecting event output

 - Do not wait unconditionally for RCU on the event migration path if
   there are no events to migrate

* tag 'perf_urgent_for_v6.3_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix the same task check in perf_event_set_output
  perf: Optimize perf_pmu_migrate_context()
parents 4ba115e2 24d3ae2f

kernel/events/core.c

+8 −6
Original line number Diff line number Diff line
@@ -12173,7 +12173,7 @@ perf_event_set_output(struct perf_event *event, struct perf_event *output_event) 
	/*

	 * If its not a per-cpu rb, it must be the same task.

	 */

	if (output_event->cpu == -1 && output_event->ctx != event->ctx)

	if (output_event->cpu == -1 && output_event->hw.target != event->hw.target)

		goto out;



	/*
@@ -12893,12 +12893,14 @@ void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu) 
	__perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->pinned_groups, &events);

	__perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->flexible_groups, &events);



	if (!list_empty(&events)) {

		/*

		 * Wait for the events to quiesce before re-instating them.

		 */

		synchronize_rcu();



		__perf_pmu_install(dst_ctx, dst_cpu, pmu, &events);

	}



	mutex_unlock(&dst_ctx->mutex);

	mutex_unlock(&src_ctx->mutex);