From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752763Ab0ESOYg (ORCPT ); Wed, 19 May 2010 10:24:36 -0400 Received: from terminus.zytor.com ([198.137.202.10]:36611 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752175Ab0ESOYd (ORCPT ); Wed, 19 May 2010 10:24:33 -0400 Message-ID: <4BF3F480.3000902@zytor.com> Date: Wed, 19 May 2010 07:24:00 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Geert Uytterhoeven CC: Ingo Molnar , Luca Barbieri , Linus Torvalds , linux-kernel@vger.kernel.org, Thomas Gleixner , Andrew Morton , linux-arch@vger.kernel.org Subject: Re: [GIT PULL] x86/atomic changes for v2.6.35 References: <20100517224531.GA27400@elte.hu> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/19/2010 04:46 AM, Geert Uytterhoeven wrote: > On Tue, May 18, 2010 at 00:45, Ingo Molnar wrote: >> Please pull the latest x86-atomic-for-linus git tree from: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-atomic-for-linus >> >> >> out-of-topic modifications in x86-atomic-for-linus: >> --------------------------------------------------- >> lib/Makefile # 86a8938: lib: Add self-test for atomic64_t >> lib/atomic64.c # 9757789: lib: Fix atomic64_add_unless retu >> lib/atomic64_test.c # a5c9161: x86, atomic64: In selftest, disti >> # 25a304f: lib: Fix atomic64_inc_not_zero te >> # 9efbcd5: lib: Fix atomic64_add_unless test >> # d7f6de1: x86: Implement atomic[64]_dec_if_ >> # 8f4f202: lib: Only test atomic64_dec_if_po >> # 86a8938: lib: Add self-test for atomic64_t > > Is having atomic64_t mandatory now? > > According to the allmodconfig build logs > (http://kisskb.ellerman.id.au/kisskb/matrix/), > several architectures (at least m68k and mips) don't have it. > Furthermore, the test fails to compile on a few architectures that do have it > (parisc, s390, sh, ...). > > > It's a pity this wasn't raised/resolved between its detection in linux-next and > before it entered mainline... > > Is having atomic64_t mandatory? Not yet, I don't think, but it probably will be soon -- which is why there is a generic implementation available. All those architectures just need to select CONFIG_GENERIC_ATOMIC64 and voilà, problem solved. As far as your boilerplate is concerned, I think Linus made it clear at the Kernel Summit that is it not the obligation of x86/ARM/PowerPC to slow down to not break the smaller architectures; it's the responsibility of those architecture maintainers to keep up. Sorry. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.