Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760570Ab2EWQzq (ORCPT ); Wed, 23 May 2012 12:55:46 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42244 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145Ab2EWQzo (ORCPT ); Wed, 23 May 2012 12:55:44 -0400 Message-ID: <4FBD167F.7080305@zytor.com> Date: Wed, 23 May 2012 09:55:27 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Linus Torvalds CC: Peter Zijlstra , Borislav Petkov , mingo@kernel.org, linux-kernel@vger.kernel.org, frank.arnold@amd.com, akpm@linux-foundation.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/mce] x86/bitops: Move BIT_64() for a wider use References: <1337684026-19740-1-git-send-email-bp@amd64.org> <1337789429.9783.16.camel@laptop> <4FBD0C47.70600@zytor.com> <20120523161932.GN14757@aftab.osrc.amd.com> <1337790571.9783.28.camel@laptop> <4FBD10D5.6080602@zytor.com> <4FBD1493.7000104@zytor.com> In-Reply-To: X-Enigmail-Version: 1.4.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 992 Lines: 26 On 05/23/2012 09:54 AM, Linus Torvalds wrote: > On Wed, May 23, 2012 at 9:47 AM, H. Peter Anvin wrote: >> >> Any reason we can't just tell people to use BIT() for a native "unsigned >> long" type (32/64 bits) and BIT_64() if they really want a 64-bit result? > > Well, that's what we're doing now. And it seems to have resulted in > repeated bugs for architectures where most of the developers run on > 64-bit machines, but the same code is actually supposed to work on > 32-bit too (ie x86). > Yes, but I fear that this will result in more subtle bugs which will therefore be even harder to detect and diagnose. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/