[PATCH 3/4] perf: Simplify perf_event_free_task()

[Peter Zijlstra]

We have ctx->event_list that contains all events; no need to
repeatedly iterate the group lists to find them all.

Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 kernel/events/core.c |   12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10567,21 +10567,11 @@ void perf_event_free_task(struct task_st
 		WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
 		put_task_struct(task); /* cannot be last */
 		raw_spin_unlock_irq(&ctx->lock);
-again:
-		list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
-				group_entry)
-			perf_free_event(event, ctx);
 
-		list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
-				group_entry)
+		list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry)
 			perf_free_event(event, ctx);
 
-		if (!list_empty(&ctx->pinned_groups) ||
-				!list_empty(&ctx->flexible_groups))
-			goto again;
-
 		mutex_unlock(&ctx->mutex);
-
 		put_ctx(ctx);
 	}
 }