From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762978AbZD3WvW (ORCPT ); Thu, 30 Apr 2009 18:51:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753536AbZD3WvO (ORCPT ); Thu, 30 Apr 2009 18:51:14 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:57858 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753402AbZD3WvN (ORCPT ); Thu, 30 Apr 2009 18:51:13 -0400 Date: Thu, 30 Apr 2009 15:49:20 -0700 From: Andrew Morton To: David Rientjes Cc: npiggin@suse.de, linux-kernel@vger.kernel.org Subject: Re: [patch] oom: prevent livelock when oom_kill_allocating_task is set Message-Id: <20090430154920.64c9c866.akpm@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Apr 2009 15:38:53 -0700 (PDT) David Rientjes wrote: > When /proc/sys/vm/oom_kill_allocating_task is set for large systems that > want to avoid the lengthy tasklist scan, it's possible to livelock if > current is ineligible for oom kill. This normally happens when it is set > to OOM_DISABLE, but is also possible if any threads are sharing the same > ->mm with a different tgid. OK... And how does the patch address this problem? Seems that if we were unable to kill `current', we'll ignore the oom_kill_allocating_task setting and will fall back the slow tasklist scan?