From: Peter Zijlstra Date: Fri, 17 Jan 2025 14:31:49 +0000 (+0100) Subject: perf: Simplify perf_event_release_kernel() X-Git-Tag: v6.16-rc1~196^2~58 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e8671e00e57b3d006ed8ae5ef055807506e44b2;p=thirdparty%2Fkernel%2Fstable.git 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: Peter Zijlstra (Intel) Reviewed-by: Ravi Bangoria Link: https://lkml.kernel.org/r/20250307193723.151721102@infradead.org --- diff --git a/kernel/events/core.c b/kernel/events/core.c index fa6dab08be47b..f75b0d38a40f2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -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 @@ again: 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