[tip:perf/urgent] perf/core: Simplify perf_event_free_task()

[tip-bot for Peter Zijlstra]

Commit-ID:  15121c789e001168decac6483d192bdb7ea29e74
Gitweb:     http://git.kernel.org/tip/15121c789e001168decac6483d192bdb7ea29e74
Author:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 16 Mar 2017 13:47:50 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 16 Mar 2017 14:16:53 +0100

perf/core: Simplify perf_event_free_task()

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

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: fweisbec@xxxxxxxxx
Link: http://lkml.kernel.org/r/20170316125823.239678244@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 kernel/events/core.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index fc7c9a8..5f21e5e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10426,21 +10426,11 @@ void perf_event_free_task(struct task_struct *task)
 		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);
 	}
 }