From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755276AbXJ3GA1 (ORCPT ); Tue, 30 Oct 2007 02:00:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753119AbXJ3GAR (ORCPT ); Tue, 30 Oct 2007 02:00:17 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:53659 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753093AbXJ3GAQ (ORCPT ); Tue, 30 Oct 2007 02:00:16 -0400 Message-ID: <4726C863.2070105@linux.vnet.ibm.com> Date: Tue, 30 Oct 2007 11:30:03 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 1.5.0.13 (X11/20070824) MIME-Version: 1.0 To: Christian Borntraeger CC: Ingo Molnar , Frans Pop , Chuck Ebbert , Greg KH , stable@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [stable] 2.6.23 regression: top displaying 9999% CPU usage References: <200710122231.50739.elendil@planet.nl> <20071029200425.GA830@elte.hu> <20071029214321.GA25669@linux.vnet.ibm.com> <200710300656.38220.borntraeger@de.ibm.com> In-Reply-To: <200710300656.38220.borntraeger@de.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christian Borntraeger wrote: > Am Montag, 29. Oktober 2007 schrieb Balbir Singh: >> We'll also need this additional patch (untested), but in the long run >> I think the approach needs to be >> >> 1. Update stime and utime at the time of context switching -- keep it >> in sync with p->sum_exec_runtime >> 2. Keep track of system/user context at system call entry points > > This is similar to what s390 and ppc64 do when CONFIG_VIRT_CPU_ACCOUNTING is > set. Whenever you do a patch, please make sure to not break the already > precise values for utime and stime on s390 and ppc. Feel free to CC me > whenever you have a patch for this. > Yes, true. I'll cc everyone on this list and send out the patch as RFC. Much of this code will be architecture specific and as you rightly pointed out, needs to happen under !CONFIG_VIRT_CPU_ACCOUNTING > Christian -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL