Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935730Ab3IELM5 (ORCPT ); Thu, 5 Sep 2013 07:12:57 -0400 Received: from mail-ea0-f178.google.com ([209.85.215.178]:52285 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759475Ab3IELMz (ORCPT ); Thu, 5 Sep 2013 07:12:55 -0400 Date: Thu, 5 Sep 2013 13:12:52 +0200 From: Ingo Molnar To: Alexey Vlasov Cc: Peter Zijlstra , Andrew Morton , Ingo Molnar , Mike Galbraith , linux-kernel@vger.kernel.org Subject: Re: Kernel migration eat CPUs Message-ID: <20130905111252.GA23362@gmail.com> References: <20130823151711.f4c1f596b4c7aa1eecccc9a6@linux-foundation.org> <20130825142837.GD31370@twins.programming.kicks-ass.net> <20130904185315.GB13294@beaver> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130904185315.GB13294@beaver> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1006 Lines: 33 * Alexey Vlasov wrote: > On Sun, Aug 25, 2013 at 04:28:37PM +0200, Peter Zijlstra wrote: > > > and a function (or function-graph) > > trace for when this happens? > > Unfortunately I could not make trace. > First when migration threads start to eat CPUs and when I turn on trace: > # echo function > current_tracer > # echo 1 > tracing_on > then server is down at once. LA comes up to several thousands, it stops > to receive commands. Sometimes I even have to reboot it. Could you try the latest -tip tree at: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git In particular this fix: 5a8e01f8fa51 sched/cputime: Do not scale when utime == 0 Could perhaps fix the phantom CPU overhead you are seeing? Thanks, Ingo -- 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/