From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262226AbUKWAur (ORCPT ); Mon, 22 Nov 2004 19:50:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261242AbUKWAsb (ORCPT ); Mon, 22 Nov 2004 19:48:31 -0500 Received: from omx3-ext.sgi.com ([192.48.171.20]:47575 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S262226AbUKVXTo (ORCPT ); Mon, 22 Nov 2004 18:19:44 -0500 Date: Mon, 22 Nov 2004 15:19:36 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Andrew Morton cc: hugh@veritas.com, torvalds@osdl.org, benh@kernel.crashing.org, nickpiggin@yahoo.com.au, linux-mm@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: deferred rss update instead of sloppy rss In-Reply-To: <20041122151628.77ab87ca.akpm@osdl.org> Message-ID: References: <20041122141148.1e6ef125.akpm@osdl.org> <20041122144507.484a7627.akpm@osdl.org> <20041122151628.77ab87ca.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 22 Nov 2004, Andrew Morton wrote: > > The timer tick occurs every 1 ms. > > That only works if the task happens to have the CPU when the timer tick > occurs. There remains no theoretical upper bound to the error in mm->rss, > and that's very easy to fix. Page fault intensive programs typically hog the cpu. But you are in principle right. The "easy fix" that you propose is to add additional logic to some very hot code paths. Then we are probably better off with another approach.