Received: by 2002:a05:6a10:206:0:0:0:0 with SMTP id 6csp1212145pxj; Fri, 4 Jun 2021 08:41:43 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy78JdwsUaS8iSzELw+tQebDgMD5iRND1o3YJai01R8aEKPtd25ahnurfPC5tl1jU8cHgZf X-Received: by 2002:a17:906:f6d7:: with SMTP id jo23mr4829103ejb.302.1622821298229; Fri, 04 Jun 2021 08:41:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1622821298; cv=none; d=google.com; s=arc-20160816; b=BfDK3JRDhXeXcYQDHOxwXMAnyowJ41urt4r8DhvjXMlj6Vb5mVUN1WkmBMp2aTqra8 0qYSyBXrQDh2XVv1t0N8PADTOVUtfAp14kER7JDwhUino6jkOti4TKsIRXPhpr1b3eKN Eq4qwOW0bL04CZLGhRQpKPQ1JGnFK7pq+YPeAyMFXcGHtXAwi15e0PExSodqMneknz1s g0ue75FSkdhxdFSYpMJMBuQ7Kd6v0N7n/rTbtFE8/gDLAu+k8WH5vfa90BOw7Ts8qV1+ mVF+vIpxG58Pvxds0ie4Uy5WHYxTlFTgbKu6bAUcwhv50t7hDOmQFMhR34q9IebK6U/s Nj0Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=E2lLRM1pcaCr/lRYhfq+QzoADLJGoY316YcVucQrPdc=; b=erVc7aeCNsTgAlYcK4+yv5FmBRJJoLLJMaFf0jsSq/pixdqYcrla1LFRj9IZCaqzCQ amrAiURbjYN/aKwQJEhWPRqDot/6Ubp6Sfaoz1jjLz2K3/T8lvZKO2JxERJsi0HtHjaX M+jc4C6h2yHSKC5av8LDYxG8iPPzebXwwgwnX5gelxYtUqQwFP7VFFPufqckBDBuCMR8 ISp3JU3XlB3FGtSiJJZEBgi32X9buXO0uWRzBRGBrwVTuUDeEtA13IWA27V+Yn6+x5yT Id0sRshNGD29kAqp47Lo42QWD5cw3pITrQtjjam83PzGDbA0xz+rjSbR8pwJf98JGkRI j/UQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id n2si708387edb.238.2021.06.04.08.41.08; Fri, 04 Jun 2021 08:41:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230361AbhFDPlk (ORCPT + 99 others); Fri, 4 Jun 2021 11:41:40 -0400 Received: from gate.crashing.org ([63.228.1.57]:45009 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229675AbhFDPlj (ORCPT ); Fri, 4 Jun 2021 11:41:39 -0400 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 154FZJvk020323; Fri, 4 Jun 2021 10:35:19 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 154FZIOg020322; Fri, 4 Jun 2021 10:35:18 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Fri, 4 Jun 2021 10:35:18 -0500 From: Segher Boessenkool To: Peter Zijlstra Cc: Linus Torvalds , will@kernel.org, paulmck@kernel.org, stern@rowland.harvard.edu, parri.andrea@gmail.com, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com, linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [RFC] LKMM: Add volatile_if() Message-ID: <20210604153518.GD18427@gate.crashing.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 04, 2021 at 01:44:37PM +0200, Peter Zijlstra wrote: > On naming (sorry Paul for forgetting that in the initial mail); while I > think using the volatile qualifier for the language feature (can we haz > plz, kthxbai) makes perfect sense, Paul felt that we might use a > 'better' name for the kernel use, ctrl_dep_if() was proposed. In standard C statements do not have qualifiers. Unless you can convince the ISO C committee to have them on "if", you will have a very hard time convincing any serious compiler to do this. Segher