Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932460AbXAIWlZ (ORCPT ); Tue, 9 Jan 2007 17:41:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932474AbXAIWlZ (ORCPT ); Tue, 9 Jan 2007 17:41:25 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:34945 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932460AbXAIWlY (ORCPT ); Tue, 9 Jan 2007 17:41:24 -0500 Date: Tue, 9 Jan 2007 23:41:00 +0100 From: Pavel Machek To: Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Greg Kroah-Hartman , Christoph Hellwig , ltt-dev@shafik.org, systemtap@sources.redhat.com, Douglas Niehaus , "Martin J. Bligh" , Thomas Gleixner Subject: Re: [PATCH] local_t : Documentation Message-ID: <20070109224100.GB6555@elf.ucw.cz> References: <20061221001545.GP28643@Krystal> <20061223093358.GF3960@ucw.cz> <20070109031446.GA29426@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070109031446.GA29426@Krystal> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1305 Lines: 31 Hi! > > > These patches extend and standardise local_t operations on each architectures, > > > allowing a rich set of atomic operations to be done on per-cpu data with > > > minimal performance impact. On some architectures, there seems to be no > > > difference between the SMP and UP operation (same memory barriers, same > > > LOCking), local.h simply includes asm-generic/local.h, which removes duplicated > > > code. > > > > Could you provide some Documentation/? Knowing when local_t can be > > used is kind-of important. > > Hi Pavel, > > Thanks for this appropriate comment. I totally agree that there is a need for > documentation about how local_t variables should be used. Here is the patch > that adds Documentation/local_ops.txt. Comments are welcome. AFAICT this fails to mention... Is local_t as big as int? As big as long? Or perhaps smaller because high bits may be needed for locking? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - 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/