From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f44.google.com (mail-pb0-f44.google.com [209.85.160.44]) by kanga.kvack.org (Postfix) with ESMTP id 81FED6B0037 for ; Fri, 11 Oct 2013 05:05:57 -0400 (EDT) Received: by mail-pb0-f44.google.com with SMTP id xa7so3897148pbc.3 for ; Fri, 11 Oct 2013 02:05:57 -0700 (PDT) Date: Fri, 11 Oct 2013 17:05:34 +0800 From: Fengguang Wu Subject: Re: [uml-devel] BUG: soft lockup for a user mode linux image Message-ID: <20131011090534.GA29330@localhost> References: <5251CF94.5040101@gmx.de> <525591AD.4060401@gmx.de> <5255A3E6.6020100@nod.at> <20131009214733.GB25608@quack.suse.cz> <5255D9A6.3010208@nod.at> <5256DA9A.5060904@gmx.de> <20131011011649.GA11191@localhost> <5257B9EB.7080503@gmx.de> <20131011085701.GA27382@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20131011085701.GA27382@localhost> Sender: owner-linux-mm@kvack.org List-ID: To: Toralf =?utf-8?Q?F=C3=B6rster?= Cc: Richard Weinberger , Jan Kara , Geert Uytterhoeven , UML devel , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , hannes@cmpxchg.org, darrick.wong@oracle.com, Michal Hocko On Fri, Oct 11, 2013 at 04:57:01PM +0800, Fengguang Wu wrote: > On Fri, Oct 11, 2013 at 10:42:19AM +0200, Toralf FA?rster wrote: > > yeah, now the picture becomes more clear > > ... > > net.core.warnings = 0 [ ok ] > > ick: pause : -717 > > ick : min_pause : -177 > > ick : max_pause : -717 > > ick: pages_dirtied : 14 > > ick: task_ratelimit: 0 > > Great and thanks! So it's the max pause calculation went wrong. However I still suspect this is not the main reason for the soft lockup. Because schedule_timeout() will directly return on negative timeout. So yes, we have encountered some negative pauses, however we still need to fix the huge dirtied pages problem which should be more fundamental. Thanks, Fengguang -- 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