Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932077AbVKWQnh (ORCPT ); Wed, 23 Nov 2005 11:43:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932078AbVKWQnh (ORCPT ); Wed, 23 Nov 2005 11:43:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:22252 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S932077AbVKWQnf (ORCPT ); Wed, 23 Nov 2005 11:43:35 -0500 Message-ID: <43849C23.3040001@suse.de> Date: Wed, 23 Nov 2005 17:43:15 +0100 From: Gerd Knorr User-Agent: Mozilla Thunderbird 1.0.6 (X11/20050715) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox Cc: Andi Kleen , Linus Torvalds , Dave Jones , Zachary Amsden , Pavel Machek , Andrew Morton , Linux Kernel Mailing List , "H. Peter Anvin" , Zwane Mwaikambo , Pratap Subrahmanyam , Christopher Li , "Eric W. Biederman" , Ingo Molnar Subject: Re: [patch] SMP alternatives References: <200511100032.jAA0WgUq027712@zach-dev.vmware.com> <20051111103605.GC27805@elf.ucw.cz> <4374F2D5.7010106@vmware.com> <4374FB89.6000304@vmware.com> <20051113074241.GA29796@redhat.com> <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> In-Reply-To: <1132764133.7268.51.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 32 Alan Cox wrote: > On Mer, 2005-11-23 at 12:17 -0700, Andi Kleen wrote: >>> + /* Paranoia */ >>> + asm volatile ("jmp 1f\n1:"); >>> + mb(); >> That would be totally obsolete 386 era paranoia. If anything then use >> a CLFLUSH (but not available on all x86s) > > If you are patching code another x86 CPU is running you must halt the > other processors and ensure it executes a serialzing instruction before > it enters any patched code. Patching in/out SMP-locking with more than one active CPU would be a pretty silly idea in the first place ;) > How many kilobytes of tables do you add to the kernel to do this > pointless stunt btw ? 16 .smp_altinstructions 0000ae0b c03b4000 003b4000 002b4000 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 17 .smp_altinstr_replacement 00000f6e c03bee0b 003bee0b 002bee0b 2**0 CONTENTS, ALLOC, LOAD, CODE cheers, Gerd - 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/