Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755915AbZJZLjt (ORCPT ); Mon, 26 Oct 2009 07:39:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755906AbZJZLjs (ORCPT ); Mon, 26 Oct 2009 07:39:48 -0400 Received: from hera.kernel.org ([140.211.167.34]:57317 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755879AbZJZLjq (ORCPT ); Mon, 26 Oct 2009 07:39:46 -0400 Date: Mon, 26 Oct 2009 11:38:46 GMT From: tip-bot for Rusty Russell Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, torvalds@linux-foundation.org, rusty@rustcorp.com.au, arjan@infradead.org, jeremy@goop.org, tglx@linutronix.de, mingo@elte.hu, js@sig21.net Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, torvalds@linux-foundation.org, arjan@infradead.org, jeremy@goop.org, tglx@linutronix.de, mingo@elte.hu, js@sig21.net In-Reply-To: <200910261426.05769.rusty@rustcorp.com.au> References: <200910261426.05769.rusty@rustcorp.com.au> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium Message-ID: Git-Commit-ID: ae1b22f6e46c03cede7cea234d0bf2253b4261cf X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1899 Lines: 49 Commit-ID: ae1b22f6e46c03cede7cea234d0bf2253b4261cf Gitweb: http://git.kernel.org/tip/ae1b22f6e46c03cede7cea234d0bf2253b4261cf Author: Rusty Russell AuthorDate: Mon, 26 Oct 2009 14:26:04 +1030 Committer: Ingo Molnar CommitDate: Mon, 26 Oct 2009 12:33:02 +0100 x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium Commit 79e1dd05d1a22 "x86: Provide an alternative() based cmpxchg64()" broke lguest, even on systems which have cmpxchg8b support. The emulation code gets used until alternatives get run, but it contains native instructions, not their paravirt alternatives. The simplest fix is to turn this code off except for 386 and 486 builds. Reported-by: Johannes Stezenbach Signed-off-by: Rusty Russell Acked-by: H. Peter Anvin Cc: lguest@ozlabs.org Cc: Arjan van de Ven Cc: Jeremy Fitzhardinge Cc: Linus Torvalds LKML-Reference: <200910261426.05769.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar --- arch/x86/Kconfig.cpu | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index f2824fb..2649840 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -400,7 +400,7 @@ config X86_TSC config X86_CMPXCHG64 def_bool y - depends on X86_PAE || X86_64 || MCORE2 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MATOM + depends on !M386 && !M486 # this should be set for all -march=.. options where the compiler # generates cmov. -- 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/