From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753228AbYIAJRE (ORCPT ); Mon, 1 Sep 2008 05:17:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752386AbYIAJQv (ORCPT ); Mon, 1 Sep 2008 05:16:51 -0400 Received: from il.qumranet.com ([212.179.150.194]:56430 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752148AbYIAJQu (ORCPT ); Mon, 1 Sep 2008 05:16:50 -0400 Message-ID: <48BBB2FF.9040104@qumranet.com> Date: Mon, 01 Sep 2008 12:16:47 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Parag Warudkar CC: Peter Zijlstra , Ingo Molnar , linux-kernel , KVM list Subject: Re: [REGRESSION] High, likely incorrect process cpu usage counters with kvm and 2.6.2[67] References: <48BABC19.1060509@qumranet.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Parag Warudkar wrote: > On Sun, Aug 31, 2008 at 11:43 AM, Avi Kivity wrote: > >> Running an idle Windows VM on Linux 2.6.26+ with kvm, one sees high values >> for the kvm process in top (30%-70% cpu), where one would normally expect >> 0%-1%. Surprisingly, the per-cpu system counters show almost 100% idle, >> leading me to believe this is an accounting error and that the process does >> not actually consume this much cpu. >> > > Busted process accounting - This looks the same as > http://bugzilla.kernel.org/show_bug.cgi?id=11209 . > Please verify. Peter's patch in latest git stops showing "incorrect > looking" CPU usage but at least the process times are still wrong, > horribly. > In fact the CPU usage thing in -rc5 is likely also incorrect but I > need to analyze that bit a little more. > > From Today's Git - > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > > 12961 parag 20 0 83000 8908 6628 R 0 0.1 5124415h npviewer.bin > > Yes, it looks very similar. In my tests, %CPU is consistent with TIME; it's just not consistent with what's actually happening and with the global statistics. -- error compiling committee.c: too many arguments to function