Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754902AbYBSOBJ (ORCPT ); Tue, 19 Feb 2008 09:01:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752410AbYBSOA4 (ORCPT ); Tue, 19 Feb 2008 09:00:56 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:42830 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbYBSOAz (ORCPT ); Tue, 19 Feb 2008 09:00:55 -0500 Date: Tue, 19 Feb 2008 15:00:33 +0100 From: Ingo Molnar To: Mathieu Desnoyers Cc: Pekka Enberg , Torsten Kaiser , Linus Torvalds , Linux Kernel Mailing List , Christoph Lameter Subject: Re: Linux 2.6.25-rc2 Message-ID: <20080219140033.GA9965@elte.hu> References: <64bb37e0802161338j306c1357m25bc224f09e6b7cd@mail.gmail.com> <20080219061107.GA23229@elte.hu> <64bb37e0802182254l49b10cbblc23f8a83d189ff8e@mail.gmail.com> <84144f020802182321x452888bai639c71ea2a5067da@mail.gmail.com> <20080219102700.GC14092@elte.hu> <20080219130253.GA29804@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080219130253.GA29804@Krystal> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1076 Lines: 26 * Mathieu Desnoyers wrote: > Ingo, a comment in slub.c explains it : > > /* > * The SLUB_FASTPATH path is provisional and is currently disabled if the > * kernel is compiled with preemption or if the arch does not support > * fast cmpxchg operations. There are a couple of coming changes that will > * simplify matters and allow preemption. Ultimately we may end up making > * SLUB_FASTPATH the default. well the feature is not complete and there are no reasons given _why_ it's not complete ... and even if there's a reason it should have been deferred to the next merge window. We still have 10 year old "this is a temporary hack" comments in the kernel ;-) "hardware does not support it" is a valid argument, "kernel developer had no time to implement it properly" is not ;-) Ingo -- 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/