From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id A791B6B003A for ; Wed, 25 Sep 2013 21:38:57 -0400 (EDT) Received: by mail-pd0-f178.google.com with SMTP id w10so439202pde.37 for ; Wed, 25 Sep 2013 18:38:57 -0700 (PDT) Message-ID: <52439022.9080407@windriver.com> Date: Thu, 26 Sep 2013 09:38:42 +0800 From: Ming Liu MIME-Version: 1.0 Subject: Re: [PATCH] oom: avoid killing init if it assume the oom killed thread's mm References: <1379929528-19179-1-git-send-email-ming.liu@windriver.com> <52427970.8010905@windriver.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: akpm@linux-foundation.org, mhocko@suse.cz, rusty@rustcorp.com.au, hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On 09/26/2013 01:56 AM, David Rientjes wrote: > On Wed, 25 Sep 2013, Ming Liu wrote: > >>> We shouldn't be selecting a process where mm == init_mm in the first >>> place, so this wouldn't fix the issue entirely. >> But if we add a control point for "mm == init_mm" in the first place(ie. in >> oom_unkillable_task), that would forbid the processes sharing mm with init to >> be selected, is that reasonable? Actually my fix is just to protect init >> process to be killed for its vfork child being selected and I think it's the >> only place where there is the risk. If my understanding is wrong, pls correct >> me. >> > We never want to select a process where task->mm == init_mm because if we > kill it we won't free any memory, regardless of vfork(). The goal of the > oom killer is solely to free memory, so it always tries to avoid needless > killing. Yes, that make sense, I will send the V1 patch. the best, thank you > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org