Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964980AbVLQVoN (ORCPT ); Sat, 17 Dec 2005 16:44:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964982AbVLQVoN (ORCPT ); Sat, 17 Dec 2005 16:44:13 -0500 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:62732 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S964980AbVLQVoM (ORCPT ); Sat, 17 Dec 2005 16:44:12 -0500 Date: Sat, 17 Dec 2005 21:44:02 +0000 From: Russell King To: Linus Torvalds Cc: David Howells , Steven Rostedt , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, akpm@osdl.org Subject: Re: [PATCH 1/12]: MUTEX: Implement mutexes Message-ID: <20051217214401.GB31551@flint.arm.linux.org.uk> Mail-Followup-To: Linus Torvalds , David Howells , Steven Rostedt , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, akpm@osdl.org References: <200512162313.jBGND7g4019623@warthog.cambridge.redhat.com> <1134791914.13138.167.camel@localhost.localdomain> <14917.1134847311@warthog.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1187 Lines: 32 On Sat, Dec 17, 2005 at 12:11:39PM -0800, Linus Torvalds wrote: > Of the other architectures you list, only ARM is really important. And no, > arm doesn't do swap. It does LL/SC (except they call it "ldrex/strex", > which I assume stands for "load/store with reservation and X just because > X is cool. Yeah, we're cool" (*)). > (*) Actually, some arm docs I found implies that "ex" stands for > "exclusive", but that leaves me wondering what the "r" stands for? FYI. The standard instructions: ldr = load register str = store register The new (ARM architecture v6 and above) atomic instructions: ldrex = load register exclusive strex = store register exclusive Previous architecture versions only have the 32-bit and 8 bit unconditional swap instructions. Luckily they're unlikely to be used for SMP in the field. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/