Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753225AbaBTCWb (ORCPT ); Wed, 19 Feb 2014 21:22:31 -0500 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:35210 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752620AbaBTCWa (ORCPT ); Wed, 19 Feb 2014 21:22:30 -0500 Message-ID: <530566DE.3090508@linux.vnet.ibm.com> Date: Thu, 20 Feb 2014 10:22:22 +0800 From: Michael wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Sasha Levin , Peter Zijlstra CC: Ingo Molnar , Dave Jones , LKML Subject: Re: sched: fair: NULL ptr deref in check_preempt_wakeup References: <52FFF7F8.2070801@oracle.com> <5301C41D.5000009@linux.vnet.ibm.com> <20140217092055.GP27965@twins.programming.kicks-ass.net> <5302C4F1.3020907@linux.vnet.ibm.com> <5304F38E.3090701@oracle.com> In-Reply-To: <5304F38E.3090701@oracle.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14022002-4790-0000-0000-00000CD3F8C5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/20/2014 02:10 AM, Sasha Levin wrote: > On 02/17/2014 09:26 PM, Michael wang wrote: >> On 02/17/2014 05:20 PM, Peter Zijlstra wrote: >> [snip] >>>> >> static void switched_to_fair(struct rq *rq, struct task_struct *p) >>>> >> { >>>> >>- if (!p->se.on_rq) >>>> >>+ struct sched_entity *se = &p->se; >>>> >>+#ifdef CONFIG_FAIR_GROUP_SCHED >>>> >>+ se->depth = se->parent ? se->parent->depth + 1 : 0; >>>> >>+#endif >>>> >>+ if (!se->on_rq) >>>> >> return; >>>> >> >>>> >> /* >>> > >>> >Yes indeed. My first idea yesterday was to put it in set_task_rq() >>> to be >>> >absolutely sure we catch all; but if this is sufficient its better. >> Agree, let's wait for Sasha's testing result then:) > > I took my time with testing it seems I'm hitting new issues with both > sched and mm, and I've wanted to confirm I don't see this one any more. > > It does seem like this patch fixes the problem for me, so: > > Tested-by: Sasha Levin Thanks for the testing :) will post the patch later. Regards, Michael Wang > > > Thanks, > Sasha > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/