Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754528AbZAZGTS (ORCPT ); Mon, 26 Jan 2009 01:19:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752194AbZAZGPt (ORCPT ); Mon, 26 Jan 2009 01:15:49 -0500 Received: from rn-out-0910.google.com ([64.233.170.186]:4033 "EHLO rn-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751403AbZAZGPs (ORCPT ); Mon, 26 Jan 2009 01:15:48 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=IMQzz0oyidg/TJyWWWIh5LJQSJkqIM7LhLlLfZoKEL3N26W9Ee0b+hKahMjac0cCLE ZXBrVvPatJlwvufAruSAMPzXKFXYmxKltxFLS7ESUT1DCNW+oDRfT8W40JeMKEUansdq Ols+GQLWr2IAVOvd6hNcwR/g/D5AzwcfX1Fnk= From: Brian Gerst To: Ingo Molnar Cc: Tejun Heo , linux-kernel@vger.kernel.org Subject: [PATCH 11/12] x86: Remove extra barriers from load_gs_base() Date: Mon, 26 Jan 2009 01:15:31 -0500 Message-Id: <1232950532-22923-11-git-send-email-brgerst@gmail.com> X-Mailer: git-send-email 1.6.1 In-Reply-To: <73c1f2160901252214k394d198dn815670e7f667b3ac@mail.gmail.com> References: <73c1f2160901252214k394d198dn815670e7f667b3ac@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1053 Lines: 34 Impact: optimization mb() generates an mfence instruction, which is not needed here. Only a compiler barrier is needed, and that is handled by the memory clobber in the wrmsrl function. Signed-off-by: Brian Gerst --- arch/x86/include/asm/processor.h | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 32c30b0..794234e 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -397,10 +397,7 @@ DECLARE_PER_CPU(char *, irq_stack_ptr); static inline void load_gs_base(int cpu) { - /* Memory clobbers used to order pda/percpu accesses */ - mb(); wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu)); - mb(); } #endif -- 1.6.1 -- 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/