From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756374Ab0IRTCp (ORCPT ); Sat, 18 Sep 2010 15:02:45 -0400 Received: from kroah.org ([198.145.64.141]:51637 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755893Ab0IRTCD (ORCPT ); Sat, 18 Sep 2010 15:02:03 -0400 X-Mailbox-Line: From gregkh@clark.site Sat Sep 18 11:59:59 2010 Message-Id: <20100918185959.668292300@clark.site> User-Agent: quilt/0.48-11.2 Date: Sat, 18 Sep 2010 11:58:44 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ingo Molnar , Peter Zijlstra , Greg KH , Mike Galbraith Subject: [080/123] sched: Fix broken assertion References: <20100918185724.290702750@clark.site> Content-Disposition: inline; filename=sched-fix-broken-assertion.patch In-Reply-To: <20100918190024.GA14388@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra commit 077614ee1e93245a3b9a4e1213659405dbeb0ba6 upstream There's a preemption race in the set_task_cpu() debug check in that when we get preempted after setting task->state we'd still be on the rq proper, but fail the test. Check for preempted tasks, since those are always on the RQ. Signed-off-by: Peter Zijlstra LKML-Reference: <20091217121830.137155561@chello.nl> Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2071,7 +2071,8 @@ void set_task_cpu(struct task_struct *p, * We should never call set_task_cpu() on a blocked task, * ttwu() will sort out the placement. */ - WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING); + WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && + !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); #endif trace_sched_migrate_task(p, new_cpu);