Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932446AbVKWVMN (ORCPT ); Wed, 23 Nov 2005 16:12:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932458AbVKWVMN (ORCPT ); Wed, 23 Nov 2005 16:12:13 -0500 Received: from clock-tower.bc.nu ([81.2.110.250]:2250 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S932446AbVKWVMB (ORCPT ); Wed, 23 Nov 2005 16:12:01 -0500 Subject: Re: [patch] SMP alternatives From: Alan Cox To: Linus Torvalds Cc: "H. Peter Anvin" , Andi Kleen , Gerd Knorr , Dave Jones , Zachary Amsden , Pavel Machek , Andrew Morton , Linux Kernel Mailing List , Zwane Mwaikambo , Pratap Subrahmanyam , Christopher Li , "Eric W. Biederman" , Ingo Molnar In-Reply-To: References: <4378A7F3.9070704@suse.de> <4379ECC1.20005@suse.de> <437A0649.7010702@suse.de> <437B5A83.8090808@suse.de> <438359D7.7090308@suse.de> <1132764133.7268.51.camel@localhost.localdomain> <20051123163906.GF20775@brahms.suse.de> <1132766489.7268.71.camel@localhost.localdomain> <4384AECC.1030403@zytor.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 23 Nov 2005 21:44:05 +0000 Message-Id: <1132782245.13095.4.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 823 Lines: 18 On Mer, 2005-11-23 at 10:42 -0800, Linus Torvalds wrote: > Of course, if it's in one of the low 12 bits of %cr3, there would have to > be a "enable this bit" in %cr4 or something. Historically, you could write > any crap in the low bits, I think. There is a much much better way to do it than just user space and without hitting cr3/cr4 - put "lock works" in the PAT and while we'll have to add PAT support which we need to do anyway we would get a world where on uniprocessor lock prefix only works on addresse targets we want it to - ie pci_alloc_consistent() pages. Alan - 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/