From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752748AbbK3Db4 (ORCPT ); Sun, 29 Nov 2015 22:31:56 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:61662 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752446AbbK3Dby (ORCPT ); Sun, 29 Nov 2015 22:31:54 -0500 Subject: Re: [PATCH] bugfix oom kill init lead panic To: Andrew Morton References: <1448880869-20506-1-git-send-email-chenjie6@huawei.com> <20151129190802.dc66cf35.akpm@linux-foundation.org> CC: , , , , , From: "Chenjie (K)" Message-ID: <565BC23F.6070302@huawei.com> Date: Mon, 30 Nov 2015 11:27:59 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151129190802.dc66cf35.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.57.123.83] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.565BC24B.00C9,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: d360c53013eac1d946de444823817f67 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My kernel version is 3.10 ,but the 4.3 is the same and the newest code is for_each_process(p) { if (!process_shares_mm(p, mm)) continue; if (same_thread_group(p, victim)) continue; if (unlikely(p->flags & PF_KTHREAD)) continue; if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) continue; so this not add the ！is_global_init also. when we vfork (CLONE_VM) a process,the copy_mm if (clone_flags & CLONE_VM) { atomic_inc(&oldmm->mm_users); mm = oldmm; goto good_mm; } use the parent mm. On 2015/11/30 11:08, Andrew Morton wrote: > On Mon, 30 Nov 2015 18:54:29 +0800 wrote: > >> From: chenjie >> >> when oom happened we can see: >> Out of memory: Kill process 9134 (init) score 3 or sacrifice child >> Killed process 9134 (init) total-vm:1868kB, anon-rss:84kB, file-rss:572kB >> Kill process 1 (init) sharing same memory >> ... >> Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 >> >> That's because: >> the busybox init will vfork a process,oom_kill_process found >> the init not the children,their mm is the same when vfork. >> >> ... >> >> --- a/mm/oom_kill.c >> +++ b/mm/oom_kill.c >> @@ -513,7 +513,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, >> rcu_read_lock(); >> for_each_process(p) >> if (p->mm == mm && !same_thread_group(p, victim) && >> - !(p->flags & PF_KTHREAD)) { >> + !(p->flags & PF_KTHREAD) && !is_global_init(p)) { >> if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) >> continue; > > What kernel version are you using? > > I don't think this can happen in current code... > > . >