Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750773AbWBBSOn (ORCPT ); Thu, 2 Feb 2006 13:14:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751157AbWBBSOn (ORCPT ); Thu, 2 Feb 2006 13:14:43 -0500 Received: from liaag1af.mx.compuserve.com ([149.174.40.32]:199 "EHLO liaag1af.mx.compuserve.com") by vger.kernel.org with ESMTP id S1750773AbWBBSOm (ORCPT ); Thu, 2 Feb 2006 13:14:42 -0500 Date: Thu, 2 Feb 2006 13:12:37 -0500 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: 2.6.16-rc1-mm4 i386 atomic operations broken on SMP (in modules at least) To: Neil Brown Cc: Andrew Morton , Gerd Hoffman , linux-kernel Message-ID: <200602021314_MC3-1-B765-7FAF@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: 1479 Lines: 37 In-Reply-To: <17377.24090.486443.865483@cse.unsw.edu.au> On Thu, 2 Feb 2006 at 12:19:22 +1100, Neil Brown wrote: > My guess is there is there is something wrong with the 'alternative' > stuff which strips out the lock prefix, but I couldn't see anything > obviously wrong. The CPUs don't have FEATURE_UP (see below) so it > cannot possibly be removing the 'lock' prefix... but it certainly acts > like it is. Look closer: > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca > cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm > constant_tsc pni monitor ds_cpl cid xtpr ^^^^^^^^^^^^ SMP alternatives is re-using the constant_tsc X86 feature bit. --- 2.6.16-rc1-mm4-386.orig/include/asm-i386/cpufeature.h +++ 2.6.16-rc1-mm4-386/include/asm-i386/cpufeature.h @@ -71,7 +71,7 @@ #define X86_FEATURE_P4 (3*32+ 7) /* P4 */ #define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */ -#define X86_FEATURE_UP (3*32+ 8) /* smp kernel running on up */ +#define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */ -- 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/