From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1D78C43603 for ; Fri, 6 Dec 2019 13:17:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2B9E24673 for ; Fri, 6 Dec 2019 13:17:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Orv0ZhCR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726332AbfLFNRN (ORCPT ); Fri, 6 Dec 2019 08:17:13 -0500 Received: from merlin.infradead.org ([205.233.59.134]:47864 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726201AbfLFNRN (ORCPT ); Fri, 6 Dec 2019 08:17:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=c/BS0k8X+8NG/g3S4NAeJDxb7dNaLWprIW3ucB/d7FI=; b=Orv0ZhCRtyr6C280YO0QMvQZ2 NLIRlOF2R1VcTi8UQ64A9l3gqUZ6zhu05V6kXJUgUQbXnPoilSWNKsCXK061mPrp7Fag5L5UudX2+ Net8OnlcMe75RQ4Gqu2hRvMi0QyYkqu+kfdYyWIO8d9zKvcRl6f9LZLYdJgDX7SQgeYB/C0MDPrrP pl6607VUyQOCfcJKRkv2g8qs8rSVqJ6TT17NQyt8UYfmbuSbrwtpfMuGeBgbKJYDPNrqkJjnnuDfz rTxYDz1H4TRsmFIb26kiFXvwmG0zj9VOdfV7n2jsezpjOT+JQBbKKlzBWzXWmmaiqIt28oOPeQ7R2 oEbok13BA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1idDTY-0007Xj-Ha; Fri, 06 Dec 2019 13:16:52 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0CC7930025A; Fri, 6 Dec 2019 14:15:33 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A750E2B275E62; Fri, 6 Dec 2019 14:16:50 +0100 (CET) Date: Fri, 6 Dec 2019 14:16:50 +0100 From: Peter Zijlstra To: Michael Ellerman Cc: Linus Torvalds , dja@axtens.net, elver@google.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, christophe.leroy@c-s.fr, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, Will Deacon , Mark Rutland Subject: Re: [GIT PULL] Please pull powerpc/linux.git powerpc-5.5-2 tag (topic/kasan-bitops) Message-ID: <20191206131650.GM2827@hirez.programming.kicks-ass.net> References: <87blslei5o.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87blslei5o.fsf@mpe.ellerman.id.au> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 06, 2019 at 11:46:11PM +1100, Michael Ellerman wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > Hi Linus, > > Please pull another powerpc update for 5.5. > > As you'll see from the diffstat this is mostly not powerpc code. In order to do > KASAN instrumentation of bitops we needed to juggle some of the generic bitops > headers. > > Because those changes potentially affect several architectures I wasn't > confident putting them directly into my tree, so I've had them sitting in a > topic branch. That branch (topic/kasan-bitops) has been in linux-next for a > month, and I've not had any feedback that it's caused any problems. > > So I think this is good to merge, but it's a standalone pull so if anyone does > object it's not a problem. No objections, but here: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=topic/kasan-bitops&id=81d2c6f81996e01fbcd2b5aeefbb519e21c806e9 you write: "Currently bitops-instrumented.h assumes that the architecture provides atomic, non-atomic and locking bitops (e.g. both set_bit and __set_bit). This is true on x86 and s390, but is not always true: there is a generic bitops/non-atomic.h header that provides generic non-atomic operations, and also a generic bitops/lock.h for locking operations." Is there any actual benefit for PPC to using their own atomic bitops over bitops/lock.h ? I'm thinking that the generic code is fairly optimal for most LL/SC architectures. I've been meaning to audit the various architectures and move them over, but alas, it's something I've not yet had time for...