Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750823AbVJHJe5 (ORCPT ); Sat, 8 Oct 2005 05:34:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750824AbVJHJe5 (ORCPT ); Sat, 8 Oct 2005 05:34:57 -0400 Received: from liaag2ad.mx.compuserve.com ([149.174.40.155]:51648 "EHLO liaag2ad.mx.compuserve.com") by vger.kernel.org with ESMTP id S1750823AbVJHJe4 (ORCPT ); Sat, 8 Oct 2005 05:34:56 -0400 Date: Sat, 8 Oct 2005 05:31:50 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: SMP syncronization on AMD processors (broken?) To: Kirill Korotaev Cc: Andrew Morton , Andrey Savochkin , Linus Torvalds , linux-kernel Message-ID: <200510080534_MC3-1-AC2C-C212@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1022 Lines: 33 In-Reply-To: <434520FF.8050100@sw.ru> On Thu, 06 Oct 2005 at 17:05:03 +0400, Kirill Korotaev wrote: > The question is whether concurrent spin_lock()'s should > acquire it in more or less "fair" fashinon or one of CPUs can starve any > arbitrary time while others do reacquire it in a loop. You neglected to say what CPU type you compiled the kernel for. If it wasn't Pentium Pro maybe you could patch include/asm-i386/spinlock.h line 82 (or the same place in x86-64) like this: ___ * (PPro errata 66, 92) */ -#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) +#if 0 #define __raw_spin_unlock_string \ "movb $1,%0" \ ___ The data might not make it out of the CPU write buffer without a locking instruction doing the update. __ Chuck - 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/