From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751002AbWHPIdR (ORCPT ); Wed, 16 Aug 2006 04:33:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751003AbWHPIdR (ORCPT ); Wed, 16 Aug 2006 04:33:17 -0400 Received: from ns.suse.de ([195.135.220.2]:44724 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751000AbWHPIdR (ORCPT ); Wed, 16 Aug 2006 04:33:17 -0400 Date: Wed, 16 Aug 2006 10:32:59 +0200 From: Andi Kleen To: David Chinner Cc: Christoph Lameter , mpm@selenic.com, Marcelo Tosatti , linux-kernel@vger.kernel.org, Nick Piggin , Andi Kleen , Manfred Spraul Subject: Re: [MODSLAB 0/7] A modular slab allocator V1 Message-Id: <20060816103259.f87c167a.ak@muc.de> In-Reply-To: <20060816081208.GL51703024@melbourne.sgi.com> References: <20060816022238.13379.24081.sendpatchset@schroedinger.engr.sgi.com> <20060816081208.GL51703024@melbourne.sgi.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.3; x86_64-unknown-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 > > 3. New slabs that are created can be merged into the kmalloc array > > if it is detected that they match. This decreases the number of caches > > and benefits cache use. > > While this will be good for reducing fragmentation, Will it? The theory behind a zone allocator like slab is that objects of the same type have similar livetimes. Fragmentation mostly happens when objects have very different live times. If you mix objects of different types into the same slab then you might get more fragmentation. kmalloc already has that problem but it probably shouldn't be added to other slabs too. -Andi