From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 9 Sep 2001 11:32:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 9 Sep 2001 11:32:36 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:23606 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Sun, 9 Sep 2001 11:32:23 -0400 Date: Sun, 9 Sep 2001 17:33:13 +0200 From: Andrea Arcangeli To: Manfred Spraul Cc: linux-kernel@vger.kernel.org, Alan Cox , torvalds@transmeta.com Subject: Re: Purpose of the mm/slab.c changes Message-ID: <20010909173313.V11329@athlon.random> In-Reply-To: <3B9B4CFE.E09D6743@colorfullife.com> <20010909162613.Q11329@athlon.random> <001201c13942$b1bec9a0$010411ac@local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <001201c13942$b1bec9a0$010411ac@local>; from manfred@colorfullife.com on Sun, Sep 09, 2001 at 05:18:00PM +0200 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 Sun, Sep 09, 2001 at 05:18:00PM +0200, Manfred Spraul wrote: > > > > it provides lifo allocations from both partial and unused slabs. > > > > lifo/fifo for unused slabs is obviously superflous - free is free, it > doesn't matter which free page is used first/last. then why don't you also make fifo the buddy allocator and the partial list as well if free is free and fifo/lifo doesn't matter? > Did you run any benchmarks? If yes, could you post them? I didn't run any specific benchmark for such change but please let me know if you can find that any real benchmark is hurted by it. I think the cleanup and the potential for lifo in the free slabs is much more sensible than the other factors you mentioned, of course there's less probability of having to fall into the free slabs rather than in the partial ones during allocations, but that doesn't mean that cannot happen very often, but I will glady suggest to remove it if you prove me wrong. All I'm saying here is that the dummy allocations with no access to the ram returned are not interesting numbers. Andrea