Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932454AbVLNLoo (ORCPT ); Wed, 14 Dec 2005 06:44:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932453AbVLNLon (ORCPT ); Wed, 14 Dec 2005 06:44:43 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:2946 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932435AbVLNLom (ORCPT ); Wed, 14 Dec 2005 06:44:42 -0500 Subject: Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation From: Arjan van de Ven To: Andrew Morton Cc: Alan Cox , dhowells@redhat.com, cfriesen@nortel.com, torvalds@osdl.org, hch@infradead.org, matthew@wil.cx, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org In-Reply-To: <20051214033536.05183668.akpm@osdl.org> References: <439EDC3D.5040808@nortel.com> <1134479118.11732.14.camel@localhost.localdomain> <3874.1134480759@warthog.cambridge.redhat.com> <15167.1134488373@warthog.cambridge.redhat.com> <1134490205.11732.97.camel@localhost.localdomain> <1134556187.2894.7.camel@laptopd505.fenrus.org> <1134558188.25663.5.camel@localhost.localdomain> <1134558507.2894.22.camel@laptopd505.fenrus.org> <1134559470.25663.22.camel@localhost.localdomain> <20051214033536.05183668.akpm@osdl.org> Content-Type: text/plain Date: Wed, 14 Dec 2005 12:44:31 +0100 Message-Id: <1134560671.2894.30.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (-2.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.8 ALL_TRUSTED Did not pass through any untrusted hosts X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 949 Lines: 26 On Wed, 2005-12-14 at 03:35 -0800, Andrew Morton wrote: > Could someone please remind me why we're even discussing this, * cleaner API * more declarative in terms of intent which in turn allow * higher performance * enhanced options like the -rt patch is doing, such as boosting processes when a semaphore they're holding hits contention * mutex use is a candidate for a "spinaphore" treatment (unlike counting semaphores) > given that > mutex_down() is slightly more costly than current down(), and mutex_up() is > appreciably more costly than current up()? that's an implementation flaw in the current implementation that is not needed by any means and that Ingo has fixed in his version of this - 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/