Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756139Ab1CNTuR (ORCPT ); Mon, 14 Mar 2011 15:50:17 -0400 Received: from mga02.intel.com ([134.134.136.20]:59707 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754351Ab1CNTuP (ORCPT ); Mon, 14 Mar 2011 15:50:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.62,317,1297065600"; d="scan'208";a="720066594" From: Andi Kleen To: Tejun Heo Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, Christoph Lameter , linux-kernel@vger.kernel.org, Andrew Morton , Pekka Enberg Subject: Re: [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the current cpu References: <20110312115010.GC2005@htj.dyndns.org> Date: Mon, 14 Mar 2011 12:49:14 -0700 In-Reply-To: <20110312115010.GC2005@htj.dyndns.org> (Tejun Heo's message of "Sat, 12 Mar 2011 12:50:10 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 608 Lines: 18 Tejun Heo writes: > Add this_cpu_has() which determines if the current cpu has a certain > ability using a segment prefix and a bit test operation. Hmm: if the CPU capability is really tested in a performance critical path, wouldn't it even be better to just use static_branch() now? -Andi -- ak@linux.intel.com -- Speaking for myself only -- 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/