From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992732AbXCBXVc (ORCPT ); Fri, 2 Mar 2007 18:21:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992735AbXCBXVc (ORCPT ); Fri, 2 Mar 2007 18:21:32 -0500 Received: from mx1.redhat.com ([66.187.233.31]:59062 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992732AbXCBXVb (ORCPT ); Fri, 2 Mar 2007 18:21:31 -0500 Message-ID: <45E8B147.4070104@redhat.com> Date: Fri, 02 Mar 2007 18:20:39 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Andrew Morton CC: Bill Irwin , Christoph Lameter , Mel Gorman , npiggin@suse.de, mingo@elte.hu, jschopp@austin.ibm.com, arjan@infradead.org, torvalds@linux-foundation.org, mbligh@mbligh.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: The performance and behaviour of the anti-fragmentation related patches References: <20070301101249.GA29351@skynet.ie> <20070301160915.6da876c5.akpm@linux-foundation.org> <45E842F6.5010105@redhat.com> <20070302085838.bcf9099e.akpm@linux-foundation.org> <20070302093501.34c6ef2a.akpm@linux-foundation.org> <45E8624E.2080001@redhat.com> <20070302100619.cec06d6a.akpm@linux-foundation.org> <45E86BA0.50508@redhat.com> <20070302211207.GJ10643@holomorphy.com> <45E894D7.2040309@redhat.com> <20070302135243.ada51084.akpm@linux-foundation.org> <45E89F1E.8020803@redhat.com> <20070302142256.0127f5ac.akpm@linux-foundation.org> <45E8A677.7000205@redhat.com> <20070302145906.653d3b82.akpm@linux-foundation.org> In-Reply-To: <20070302145906.653d3b82.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Somehow I don't believe that a person or organisation which is incapable of > preparing even a simple testcase will be capable of fixing problems such as > this without breaking things. I don't believe anybody who relies on one simple test case will ever be capable of evaluating a patch without breaking things. Test cases can show problems, but fixing a test case is no guarantee at all that your VM will behave ok with real world workloads. Test cases for the VM can *never* be relied on to show that a problem went away. I'll do my best, but I can't promise a simple test case for every single problem that's plaguing the VM. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45E8B147.4070104@redhat.com> Date: Fri, 02 Mar 2007 18:20:39 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: The performance and behaviour of the anti-fragmentation related patches References: <20070301101249.GA29351@skynet.ie> <20070301160915.6da876c5.akpm@linux-foundation.org> <45E842F6.5010105@redhat.com> <20070302085838.bcf9099e.akpm@linux-foundation.org> <20070302093501.34c6ef2a.akpm@linux-foundation.org> <45E8624E.2080001@redhat.com> <20070302100619.cec06d6a.akpm@linux-foundation.org> <45E86BA0.50508@redhat.com> <20070302211207.GJ10643@holomorphy.com> <45E894D7.2040309@redhat.com> <20070302135243.ada51084.akpm@linux-foundation.org> <45E89F1E.8020803@redhat.com> <20070302142256.0127f5ac.akpm@linux-foundation.org> <45E8A677.7000205@redhat.com> <20070302145906.653d3b82.akpm@linux-foundation.org> In-Reply-To: <20070302145906.653d3b82.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Bill Irwin , Christoph Lameter , Mel Gorman , npiggin@suse.de, mingo@elte.hu, jschopp@austin.ibm.com, arjan@infradead.org, torvalds@linux-foundation.org, mbligh@mbligh.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Andrew Morton wrote: > Somehow I don't believe that a person or organisation which is incapable of > preparing even a simple testcase will be capable of fixing problems such as > this without breaking things. I don't believe anybody who relies on one simple test case will ever be capable of evaluating a patch without breaking things. Test cases can show problems, but fixing a test case is no guarantee at all that your VM will behave ok with real world workloads. Test cases for the VM can *never* be relied on to show that a problem went away. I'll do my best, but I can't promise a simple test case for every single problem that's plaguing the VM. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org