From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754956AbaJIBLY (ORCPT ); Wed, 8 Oct 2014 21:11:24 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.227]:27083 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752989AbaJIBLF (ORCPT ); Wed, 8 Oct 2014 21:11:05 -0400 Message-Id: <20141009011057.177972498@goodmis.org> User-Agent: quilt/0.61-1 Date: Wed, 08 Oct 2014 21:10:11 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Fengguang Wu , "Peter Zijlstra (Intel)" Subject: [for-next][PATCH 1/2] tracing: Robustify wait loop References: <20141009011010.446507073@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0001-tracing-Robustify-wait-loop.patch X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra The pending nested sleep debugging triggered on the potential stale TASK_INTERRUPTIBLE in this code. While there, fix the loop such that we won't revert to a while(1) yield() 'spin' loop if we ever get a spurious wakeup. And fix the actual issue by properly terminating the 'wait' loop by setting TASK_RUNNING. Link: http://lkml.kernel.org/p/20141008165110.GA14547@worktop.programming.kicks-ass.net Reported-by: Fengguang Wu Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ef06ce7e9cf8..0cc51edde3a8 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2513,8 +2513,11 @@ static __init int event_test_thread(void *unused) kfree(test_malloc); set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) + while (!kthread_should_stop()) { schedule(); + set_current_state(TASK_INTERRUPTIBLE); + } + __set_current_state(TASK_RUNNING); return 0; } -- 2.0.1