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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68747C7EE22 for ; Mon, 15 May 2023 09:45:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239895AbjEOJpi (ORCPT ); Mon, 15 May 2023 05:45:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241127AbjEOJpL (ORCPT ); Mon, 15 May 2023 05:45:11 -0400 Received: from new3-smtp.messagingengine.com (new3-smtp.messagingengine.com [66.111.4.229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DFDC1BD7; Mon, 15 May 2023 02:43:44 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailnew.nyi.internal (Postfix) with ESMTP id DD5495803CE; Mon, 15 May 2023 05:43:41 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute6.internal (MEProxy); Mon, 15 May 2023 05:43:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:content-type:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm3; t=1684143821; x=1684151021; bh=rh DpJI+VS2ftRNM4C+B3O914qD0XGOeUnvYVI19CEcc=; b=ouvD58uxjfNX4wP0nP xvpLpKJ0T+XQe0vE3+HQlIgXzQFoYhQav58t5Dt2KUNupaE1hauor5HqsvRweZIA n7VUIbSESGSsJAS4/IBRJKBSsxxY38GuTgOajMXeSWSgJQimKnSYKuYGHWHVY4NP /Z9Gf1cMeQiyDMZN5qrJRzyawySnZgkgQbE4fwGD0ipwb+g7TY93g3qvv7gHFwjA LLXU0AdO2UkJkc2revwtVIywBQkAzGtx29mZ5LC6bOrEx+xHyUGvBZi9mcGzUgv7 bZKliDv8gyReD6p2qApGsiWp78ZcFzHWVRJfXszfRmnRY8Ih0GVViZweQT8LUDUT mtnw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:content-type:date:date :feedback-id:feedback-id:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; t=1684143821; x=1684151021; bh=rhDpJI+VS2ftR NM4C+B3O914qD0XGOeUnvYVI19CEcc=; b=W0CbDVAPadlsN/NG6WntcvQsG7eam 98jhjJQ/QA65KOBFXAByPwX2xRzcv5kefvCfHPyQfFXa0MZRfWDETlJBF1OM7JTd KGU/Srx/r17/VNHIFDuh+T58q6Lcf9BWxvGxNcF3d0lxRehwVtidwFFf4DBPLiXJ cJfmJ30HkBGxX4vJRin9a4WPll+IgH7hNRfqTxWjs8QSbe4SPY5P4YZHkg9FjAh6 Vckfzq4j7n1ln9MnIkonN2rGXhPG0IqlKgKNjAzWvEmgORkY0ycBuLQj62JeA408 +aj8JQv1XXfSBVZ5xCX6pwqZJ1zQHl98KBdzzqe14Hydi21btJoSo9DIA== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrfeehjedgudelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepofgfggfkjghffffhvfevufgtsehttdertderredtnecuhfhrohhmpedftehr nhguuceuvghrghhmrghnnhdfuceorghrnhgusegrrhhnuggsrdguvgeqnecuggftrfgrth htvghrnhepffehueegteeihfegtefhjefgtdeugfegjeelheejueethfefgeeghfektdek teffnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomheprg hrnhgusegrrhhnuggsrdguvg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 7747DB60086; Mon, 15 May 2023 05:43:39 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-415-gf2b17fe6c3-fm-20230503.001-gf2b17fe6 Mime-Version: 1.0 Message-Id: <4975b92f-92f6-4d50-8386-9add12ddfd61@app.fastmail.com> In-Reply-To: <20230515075659.118447996@infradead.org> References: <20230515075659.118447996@infradead.org> Date: Mon, 15 May 2023 11:42:23 +0200 From: "Arnd Bergmann" To: "Peter Zijlstra" , "Linus Torvalds" Cc: "Jonathan Corbet" , "Will Deacon" , "Boqun Feng" , "Mark Rutland" , "Catalin Marinas" , dennis@kernel.org, "Tejun Heo" , "Christoph Lameter" , "Heiko Carstens" , gor@linux.ibm.com, "Alexander Gordeev" , borntraeger@linux.ibm.com, "Sven Schnelle" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , x86@kernel.org, "H. Peter Anvin" , "Joerg Roedel" , suravee.suthikulpanit@amd.com, "Robin Murphy" , "David Woodhouse" , "Baolu Lu" , "Herbert Xu" , "David S . Miller" , "Pekka Enberg" , "David Rientjes" , "Joonsoo Kim" , "Andrew Morton" , "Vlastimil Babka" , "Roman Gushchin" , "Hyeonggon Yoo" <42.hyeyoo@gmail.com>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, iommu@lists.linux.dev, Linux-Arch , linux-crypto@vger.kernel.org Subject: Re: [PATCH v3 00/11] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 15, 2023, at 09:56, Peter Zijlstra wrote: > > Since v2: > > - reworked this_cpu_cmpxchg() to not implicity do u128 but provide explicit > this_cpu_cmpxchg128() (arnd) > - added try_cmpxchg12_local() (per the addition of the try_cmpxchg*_local() > family of functions) > - slight cleanup of the SLUB conversion (due to rebase and having to touch it) > - added a 'cleanup' patch for SLUB, since I was staring at that anyway > This is clearly an improvement over the previous state, so I'm happy with that, and the explicit this_cpu_cmpxchg128() interface addresses most of my previous concerns. Reviewed-by: Arnd Bergmann The need for runtime feature checking in the callers on x86-64 is still a bit awkward, but this is no worse than before. I understand that turning this into a compile-time choice would require first settling a larger debate about raising the default target for distros beyond the current CONFIG_GENERIC_CPU. Arnd