[PATCH v2 05/24] perf: Simplify perf_event_release_kernel()

Peter Zijlstra posted 24 patches 1 year ago
There is a newer version of this series
[PATCH v2 05/24] perf: Simplify perf_event_release_kernel()
Posted by Peter Zijlstra 1 year ago
Get rid of the free_list...

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 kernel/events/core.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5462,7 +5462,6 @@ int perf_event_release_kernel(struct per
 {
 	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
@@ -5531,27 +5530,26 @@ int perf_event_release_kernel(struct per
 					       struct perf_event, child_list);
 		if (tmp == child) {
 			perf_remove_from_context(child, DETACH_GROUP | DETACH_CHILD);
-			list_add(&child->child_list, &free_list);
 			/*
 			 * This matches the refcount bump in inherit_event();
 			 * this can't be the last reference.
 			 */
 			put_event(event);
+		} else {
+			child = NULL;
 		}
 
 		mutex_unlock(&event->child_mutex);
 		mutex_unlock(&ctx->mutex);
+
+		if (child)
+			free_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);
-		free_event(child);
-	}
-
 no_ctx:
 	put_event(event); /* Must be the 'last' reference */
 	return 0;