Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933795AbYB2T51 (ORCPT ); Fri, 29 Feb 2008 14:57:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760060AbYB2T5S (ORCPT ); Fri, 29 Feb 2008 14:57:18 -0500 Received: from relay1.sgi.com ([192.48.171.29]:54321 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758517AbYB2T5R (ORCPT ); Fri, 29 Feb 2008 14:57:17 -0500 Date: Fri, 29 Feb 2008 11:57:16 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Mathieu Desnoyers cc: Eric Dumazet , Pekka Enberg , Torsten Kaiser , Ingo Molnar , Linus Torvalds , Linux Kernel Mailing List Subject: Re: [PATCH] Implement slub fastpath in terms of freebase and freeoffset In-Reply-To: <20080229130348.GA9714@Krystal> Message-ID: References: <20080219200358.GB11197@Krystal> <20080228055510.GA9026@Krystal> <20080228232507.GB20319@Krystal> <20080229015621.GB32200@Krystal> <20080229033255.GA2200@Krystal> <20080229130348.GA9714@Krystal> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1176 Lines: 28 On Fri, 29 Feb 2008, Mathieu Desnoyers wrote: > > Then we do not need the page->end field anymore right? I will try > > to rediff your patch against current slab-mm and see how we can proceed > > from there. > > I guess you could replace page->end with the (expensive) > page_address(page) + 1 in new_slab. > > You would also have to change slab_address() to use > page_address(page). Since this is used by check_valid_pointer, I am not > sure it's a good idea to use this slow operation there. > > Or maybe you have a different alternative in mind ? page->end was introduced to have a unique pointer for each slab. The counter that you introduces can take over that role. So we could use a NULL pointer again as the end of the objects? Or some constant? I am going to revert the change that introduced page->end for 2.6.25 since it seems that the new fastpath does not need this. It was specific to the old fastpath. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/