From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 695C96B0071 for ; Wed, 16 Jun 2010 11:10:44 -0400 (EDT) Received: by pwi7 with SMTP id 7so4331424pwi.14 for ; Wed, 16 Jun 2010 08:10:42 -0700 (PDT) Date: Thu, 17 Jun 2010 00:02:32 +0900 From: Minchan Kim Subject: Re: [PATCH 3/9] oom: oom_kill_process() doesn't select kthread child Message-ID: <20100616150232.GC9278@barrios-desktop> References: <20100616201948.72D7.A69D9226@jp.fujitsu.com> <20100616203126.72DD.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100616203126.72DD.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , David Rientjes , KAMEZAWA Hiroyuki List-ID: On Wed, Jun 16, 2010 at 08:32:08PM +0900, KOSAKI Motohiro wrote: > Now, select_bad_process() have PF_KTHREAD check, but oom_kill_process > doesn't. It mean oom_kill_process() may choose wrong task, especially, > when the child are using use_mm(). Now oom_kill_process is called by three place. 1. mem_cgroup_out_of_memory 2. out_of_memory with sysctl_oom_kill_allocating_task 3. out_of_memory with non-sysctl_oom_kill_allocating_task I think it's no problem in 1 and 3 since select_bad_process already checks PF_KTHREAD. The problem in in 2. So How about put the check before calling oom_kill_process in case of sysctl_oom_kill_allocating task? if (sysctl_oom_kill_allocating_task) { if (!current->flags & PF_KTHREAD) oom_kill_process(); It can remove duplicated PF_KTHREAD check in select_bad_process and oom_kill_process. -- Kind regards, Minchan Kim -- 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