From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 8A8D66B01C6 for ; Thu, 14 May 2009 10:16:08 -0400 (EDT) Message-ID: <4A0C27AA.4010006@zytor.com> Date: Thu, 14 May 2009 07:16:10 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH] x86: Extend test_and_set_bit() test_and_clean_bit() to 64 bits in X86_64 References: <1242202647-32446-1-git-send-email-sheng@linux.intel.com> <87zldhl7ne.fsf@basil.nowhere.org> <200905141145.05591.sheng@linux.intel.com> <20090514083250.GD19296@one.firstfloor.org> <4A0C262B.3060303@zytor.com> <20090514141649.GD10933@one.firstfloor.org> In-Reply-To: <20090514141649.GD10933@one.firstfloor.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: Sheng Yang , linux-kernel@vger.kernel.org, linux-mm , Ingo Molnar List-ID: Andi Kleen wrote: >>> >> The right way to do it is to pass the proper type of register. > > For the input index register you don't actually need 64bit and for the > value it's typically memory anyways. > If you have a 64-bit operation you have a 64-bit index register. And you need a 64-bit index for it to handle over 2^31 (since it is signed.) -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org