Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755193Ab3HPPTe (ORCPT ); Fri, 16 Aug 2013 11:19:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32302 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755048Ab3HPPTd (ORCPT ); Fri, 16 Aug 2013 11:19:33 -0400 Date: Fri, 16 Aug 2013 17:13:39 +0200 From: Oleg Nesterov To: Frederic Weisbecker Cc: Jaromir Capik , Andrew Morton , Michal Hocko , Martin Schwidefsky , Ingo Molnar , Thomas Gleixner , Ania Honess , atomlin@redhat.com, asolanas@redhat.com, linux-kernel@vger.kernel.org Subject: Re: proc/stat: idle goes backward Message-ID: <20130816151339.GA29675@redhat.com> References: <1904614521.2884383.1376487067689.JavaMail.root@redhat.com> <1277145964.2082352.1376490809716.JavaMail.root@redhat.com> <20130816144704.GA25904@redhat.com> <20130816150122.GB24210@somewhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130816150122.GB24210@somewhere> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1099 Lines: 34 On 08/16, Frederic Weisbecker wrote: > > On Fri, Aug 16, 2013 at 04:47:04PM +0200, Oleg Nesterov wrote: > > > > Questions: > > > > - Any other reason why it can be non-monotonic? > > > > - Should we fix this or should we document that userspace > > should handle this itself? > > > > IOW, is this is bug or not? > > I don't know if we want to fix it (I personally think we should because it is not the > first time I hear complains about this) but if we do, here is a possible fix: > > https://lkml.org/lkml/2013/8/8/638 Thanks! it is not easy to read the patches on lkml.org and I do not understand this code enough. But it seems that this should address my concerns, including the "even ignoring drivers/cpuidle/". Except, I am not sure that these changes handle the case when nr_iowait() change in between. Are you going to resend? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/