From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751659AbWFVGPa (ORCPT ); Thu, 22 Jun 2006 02:15:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751664AbWFVGPa (ORCPT ); Thu, 22 Jun 2006 02:15:30 -0400 Received: from smtp.osdl.org ([65.172.181.4]:18659 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751659AbWFVGP3 (ORCPT ); Thu, 22 Jun 2006 02:15:29 -0400 Date: Wed, 21 Jun 2006 23:15:00 -0700 From: Andrew Morton To: Christoph Lameter Cc: a.p.zijlstra@chello.nl, linux-mm@kvack.org, linux-kernel@vger.kernel.org, hugh@veritas.com, dhowells@redhat.com, christoph@lameter.com, mbligh@google.com, npiggin@suse.de, torvalds@osdl.org Subject: Re: [PATCH 1/6] mm: tracking shared dirty pages Message-Id: <20060621231500.7d00dba4.akpm@osdl.org> In-Reply-To: References: <20060619175243.24655.76005.sendpatchset@lappy> <20060619175253.24655.96323.sendpatchset@lappy> <20060621225639.4c8bad93.akpm@osdl.org> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.17; i686-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 X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 Jun 2006 23:07:37 -0700 (PDT) Christoph Lameter wrote: > On Wed, 21 Jun 2006, Andrew Morton wrote: > > > Performance testing is critical here. I think some was done, but I don't > > reall what tests were performed, nor do I remember the results. Without such > > info it's not possible to make a go/no-go decision. > > Tests did show that there was no performance regression for the usual > tests. That is to be expected since the patch should only modify the > behavior of shared writable mapping. The use of those is rare in typical > benchmarks. Of course. In this case one should prepare an artificial microbenchmark so we can understand the worst case.