Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933469AbaLEBsc (ORCPT ); Thu, 4 Dec 2014 20:48:32 -0500 Received: from mga01.intel.com ([192.55.52.88]:29345 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751827AbaLEBsa convert rfc822-to-8bit (ORCPT ); Thu, 4 Dec 2014 20:48:30 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,519,1413270000"; d="scan'208";a="632994532" From: "Liu, Chuansheng" To: Vincent Guittot , "Zhang, Jun" CC: "mingo@redhat.com" , Peter Zijlstra , "gregkh@linuxfoundation.org" , Hillf Danton , linux-kernel , "stable@vger.kernel.org" , "Liu, Changcheng" Subject: RE: [PATCH v2] sched/fair: fix find_idlest_cpu return -1 Thread-Topic: [PATCH v2] sched/fair: fix find_idlest_cpu return -1 Thread-Index: AQHQD7wbCzODxs4zUUK8CCYucqaN15yAOvRg Date: Fri, 5 Dec 2014 01:48:25 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A01EEA8AF@SHSMSX101.ccr.corp.intel.com> References: <1417693435-18247-1-git-send-email-jun.zhang@intel.com> In-Reply-To: Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Vincent Guittot [mailto:vincent.guittot@linaro.org] > Sent: Thursday, December 04, 2014 8:15 PM > To: Zhang, Jun > Cc: mingo@redhat.com; Peter Zijlstra; gregkh@linuxfoundation.org; Hillf > Danton; linux-kernel; stable@vger.kernel.org; Liu, Chuansheng; Liu, > Changcheng > Subject: Re: [PATCH v2] sched/fair: fix find_idlest_cpu return -1 > > On 4 December 2014 at 12:43, wrote: > > From: zhang jun > > > > in function select_task_rq_fair, when find_idlest_cpu return -1 and sd->child > == NULL > > select_task_rq_fair return -1, system panic. > > you forgot to add on which kernel version this patch applies. > > We don't have such issue on 3.18-rc7 as find_idlest_cpu don't return > -1. We only need a cleanup of the test against -1 for 3.18-rc > Agreed, so Jun can make two patches: The first one patch is in find_idlest_cpu() to not return -1 and based on stable-branch such as 3.14.x; The second patch is one cleanup for new_cpu == -1 judgment against the 3.18-rc, since it is no possibility now; Best Regards Chuansheng -- 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/