From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933256Ab0KOSAh (ORCPT ); Mon, 15 Nov 2010 13:00:37 -0500 Received: from mtagate4.de.ibm.com ([195.212.17.164]:57423 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756551Ab0KOSAg (ORCPT ); Mon, 15 Nov 2010 13:00:36 -0500 Date: Mon, 15 Nov 2010 19:00:31 +0100 From: Martin Schwidefsky To: Peter Zijlstra Cc: Oleg Nesterov , Michael Holzheu , Shailabh Nagar , Andrew Morton , Venkatesh Pallipadi , Suresh Siddha , Ingo Molnar , John stultz , Thomas Gleixner , Balbir Singh , Heiko Carstens , Roland McGrath , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [RFC][PATCH v2 5/7] taskstats: Improve cumulative CPU time accounting Message-ID: <20101115190031.5a50e760@mschwide.boeblingen.de.ibm.com> In-Reply-To: <1289843517.2109.521.camel@laptop> References: <20101111170352.732381138@linux.vnet.ibm.com> <20101111170815.404670062@linux.vnet.ibm.com> <20101113183810.GA9021@redhat.com> <20101115165521.21baac60@mschwide.boeblingen.de.ibm.com> <1289837036.2109.501.camel@laptop> <20101115184910.549a828b@mschwide.boeblingen.de.ibm.com> <1289843517.2109.521.camel@laptop> Organization: IBM Corporation X-Mailer: Claws Mail 3.7.6 (GTK+ 2.20.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 Nov 2010 18:51:57 +0100 Peter Zijlstra wrote: > On Mon, 2010-11-15 at 18:49 +0100, Martin Schwidefsky wrote: > > > To what purpose? > > > > Is that a trick question? Why do we have tools like "top"? Or process > > accounting? The point is that the quality of the numbers we get right > > now is rather bad, the overhead of scanning /proc is horrendous and > > the 10ms granularity is rather coarse. > > But you're not just replacing top, you're adding all kinds of new > accounting crap all over the place. We DO replace top. Patch #7 of 7. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.