Commit 3e8671e0 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

perf: Simplify perf_event_release_kernel() 



There is no good reason to have the free list anymore. It is possible
to call free_event() after the locks have been dropped in the main
loop.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Link: https://lkml.kernel.org/r/20250307193723.151721102@infradead.org
parent 59f3aa4a

kernel/events/core.c

+7 −8
Original line number Diff line number Diff line
@@ -5696,7 +5696,6 @@ int perf_event_release_kernel(struct perf_event *event) 
{

	struct perf_event_context *ctx = event->ctx;

	struct perf_event *child, *tmp;

	LIST_HEAD(free_list);



	/*

	 * If we got here through err_alloc: free_event(event); we will not
@@ -5765,23 +5764,23 @@ int perf_event_release_kernel(struct perf_event *event) 
					       struct perf_event, child_list);

		if (tmp == child) {

			perf_remove_from_context(child, DETACH_GROUP | DETACH_CHILD);

			list_add(&child->child_list, &free_list);

		} else {

			child = NULL;

		}



		mutex_unlock(&event->child_mutex);

		mutex_unlock(&ctx->mutex);



		if (child) {

			/* Last reference unless ->pending_task work is pending */

			put_event(child);

		}

		put_ctx(ctx);



		goto again;

	}

	mutex_unlock(&event->child_mutex);



	list_for_each_entry_safe(child, tmp, &free_list, child_list) {

		list_del(&child->child_list);

		/* Last reference unless ->pending_task work is pending */

		put_event(child);

	}



no_ctx:

	/*

	 * Last reference unless ->pending_task work is pending on this event