From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S971234AbXEIAdk (ORCPT ); Tue, 8 May 2007 20:33:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752055AbXEIAdc (ORCPT ); Tue, 8 May 2007 20:33:32 -0400 Received: from waste.org ([66.93.16.53]:60380 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbXEIAdc (ORCPT ); Tue, 8 May 2007 20:33:32 -0400 Date: Tue, 8 May 2007 19:33:23 -0500 From: Matt Mackall To: Alan Cox Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, clameter@sgi.com Subject: Re: + fix-spellings-of-slab-allocator-section-in-init-kconfig.patch added to -mm tree Message-ID: <20070509003323.GX11115@waste.org> References: <200705082302.l48N2KrZ004229@shell0.pdx.osdl.net> <20070509002307.GV11115@waste.org> <20070509013220.02093f2e@the-village.bc.nu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070509013220.02093f2e@the-village.bc.nu> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 09, 2007 at 01:32:20AM +0100, Alan Cox wrote: > > (without SLAB emulation) and fragmentation was not the driving force > > for replacement. Small Linux 1.x machines frequently had uptimes of 1+ > > years without fragmenting to death. Instead, it was performance with > > 8MB for a bit over 3 years.... (1.2.13lmp) > > The fragmentation issue I think is overbaked. A lot of the academic work > argues that there is pretty much no long term difference between first > fit, best fit, and most of the clever algorithms (obviously stupid ones > like "take the middle out of the biggest space allocator" do perform > worse). For MMUless boxes fragmentation is a big issue but not for normal > systems. Further, the received wisdom that fragmentation of SLAB-like systems is better is not above doubt. Our own issues with dcache fragmentation suggest it's far from perfect. -- Mathematics is the supreme nostalgia of our time.