From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 2 May 2002 11:59:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 2 May 2002 11:59:10 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:24897 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Thu, 2 May 2002 11:59:10 -0400 Date: Thu, 2 May 2002 17:59:46 +0200 From: Andrea Arcangeli To: William Lee Irwin III , Daniel Phillips , Russell King , linux-kernel@vger.kernel.org Subject: Re: Bug: Discontigmem virt_to_page() [Alpha,ARM,Mips64?] Message-ID: <20020502175946.H11414@dualathlon.random> In-Reply-To: <20020426192711.D18350@flint.arm.linux.org.uk> <20020501042341.G11414@dualathlon.random> <20020502024740.P11414@dualathlon.random> <20020502023711.GF32767@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.22.1i X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 01, 2002 at 07:37:11PM -0700, William Lee Irwin III wrote: > On Thu, May 02, 2002 at 02:47:40AM +0200, Andrea Arcangeli wrote: > > Oh yeah, you save 1 microsecond every 10 years of uptime by taking > > advantage of the potentially coalesced cacheline between the last page > > in a node and the first page of the next node. Before you can care about > > this optimizations you should remove from x86 the pgdat loops that are > > not needed with discontigmem disabled like in x86 (this has nothing to > > do with discontigmem/nonlinear). That wouldn't be measurable too but at > > least it would be more worthwhile. > > Which ones did you have in mind? I did poke around this area a bit, and all of them, if you implement a mechanism to skip one of the pgdat loops, you could skip them of all then. > already have my eye on one... > > > Cheers, > Bill Andrea