From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261311AbTEYEPK (ORCPT ); Sun, 25 May 2003 00:15:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261312AbTEYEPK (ORCPT ); Sun, 25 May 2003 00:15:10 -0400 Received: from holomorphy.com ([66.224.33.161]:12444 "EHLO holomorphy") by vger.kernel.org with ESMTP id S261311AbTEYEPJ (ORCPT ); Sun, 25 May 2003 00:15:09 -0400 Date: Sat, 24 May 2003 21:28:03 -0700 From: William Lee Irwin III To: Con Kolivas Cc: Christian Klose , Marc-Christian Petersen , Linux Kernel Mailing List Subject: Re: I/O problems in 2.4.19/2.4.20/2.4.21-rc3 Message-ID: <20030525042803.GA8978@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Con Kolivas , Christian Klose , Marc-Christian Petersen , Linux Kernel Mailing List References: <200305231405.54599.christian.klose@freenet.de> <20030524142809.GZ8978@holomorphy.com> <200305250242.58269.christian.klose@freenet.de> <200305251127.40516.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200305251127.40516.kernel@kolivas.org> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 25, 2003 at 11:27:20AM +1000, Con Kolivas wrote: > Even though you're not Marc I do agree with you. The problem is well > described as either poor interactivity (the window wiggle test) or > starvation in the presence of certain scheduler hogs (for whatever > reason) since the interactivity patch from mingo. Dropping the max > timeslice is a bandaid but destroys priority based timeslice > scheduling. Dropping the min timeslice will bring this back, but at > some point the timeslice will be so low that low priority cpu > intensive tasks will spend most of their time cache trashing. The fact that it's a "bandaid" and that it "destroys priority-based timeslice scheduling" makes it a shenanigan. If you're having problems solved by capping timeslices, you have someone's timeslice and/or priority growing too large for some reason. It'd be far better to help figure out what went wrong. -- wli