From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id B660E6B01CA for ; Thu, 3 Jun 2010 02:25:20 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o536PKP8009501 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 3 Jun 2010 15:25:20 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 2B80345DE55 for ; Thu, 3 Jun 2010 15:25:20 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 055DB45DE54 for ; Thu, 3 Jun 2010 15:25:20 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id D88781DB8052 for ; Thu, 3 Jun 2010 15:25:19 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 8ACCD1DB8044 for ; Thu, 3 Jun 2010 15:25:19 +0900 (JST) From: KOSAKI Motohiro Subject: [PATCH 09/12] oom: remove PF_EXITING check completely In-Reply-To: <20100603135106.7247.A69D9226@jp.fujitsu.com> References: <20100603135106.7247.A69D9226@jp.fujitsu.com> Message-Id: <20100603152436.7262.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 3 Jun 2010 15:25:18 +0900 (JST) Sender: owner-linux-mm@kvack.org To: "Luis Claudio R. Goncalves" , LKML , linux-mm , Oleg Nesterov , David Rientjes , Andrew Morton , KAMEZAWA Hiroyuki , Nick Piggin Cc: kosaki.motohiro@jp.fujitsu.com List-ID: Currently, PF_EXITING check is completely broken. because 1) It only care main-thread and ignore sub-threads 2) If user enable core-dump feature, it can makes deadlock because the task during coredump ignore SIGKILL. The deadlock is certenaly worst result, then, minor PF_EXITING optimization worth is relatively ignorable. This patch removes it. Signed-off-by: KOSAKI Motohiro Acked-by: Oleg Nesterov --- mm/oom_kill.c | 27 --------------------------- 1 files changed, 0 insertions(+), 27 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 6360c56..5d723fb 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -302,24 +302,6 @@ static struct task_struct *select_bad_process(unsigned long *ppoints, if (test_tsk_thread_flag(p, TIF_MEMDIE)) return ERR_PTR(-1UL); - /* - * This is in the process of releasing memory so wait for it - * to finish before killing some other task by mistake. - * - * However, if p is the current task, we allow the 'kill' to - * go ahead if it is exiting: this will simply set TIF_MEMDIE, - * which will allow it to gain access to memory reserves in - * the process of exiting and releasing its resources. - * Otherwise we could get an easy OOM deadlock. - */ - if (p->flags & PF_EXITING) { - if (p != current) - return ERR_PTR(-1UL); - - chosen = p; - *ppoints = ULONG_MAX; - } - points = badness(p, uptime.tv_sec); if (points > *ppoints || !chosen) { chosen = p; @@ -444,15 +426,6 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, if (printk_ratelimit()) dump_header(p, gfp_mask, order, mem); - /* - * If the task is already exiting, don't alarm the sysadmin or kill - * its children or threads, just set TIF_MEMDIE so it can die quickly - */ - if (p->flags & PF_EXITING) { - __oom_kill_process(p, mem, 0); - return 0; - } - printk(KERN_ERR "%s: kill process %d (%s) score %li or a child\n", message, task_pid_nr(p), p->comm, points); -- 1.6.5.2 -- 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