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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 2A325C7618B for ; Fri, 26 Jul 2019 14:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5CFC21850 for ; Fri, 26 Jul 2019 14:07:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EBcVkDbk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727584AbfGZOHm (ORCPT ); Fri, 26 Jul 2019 10:07:42 -0400 Received: from mail-ed1-f67.google.com ([209.85.208.67]:44158 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726784AbfGZOHl (ORCPT ); Fri, 26 Jul 2019 10:07:41 -0400 Received: by mail-ed1-f67.google.com with SMTP id k8so53365113edr.11; Fri, 26 Jul 2019 07:07:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=zWt0jo8AMAZchPeNnT8VtD1Yz35B0VOWcsrzm+hetHc=; b=EBcVkDbkQNLVIGiixEGt7/effrRULBIFCXd9TZAffqJ0lq9fLauFVglwd8b2bkfIyN BC2KTJ0r7uFjeAiEasWUgU6aWedhVoGCjUdR79nMIVUDf9eRmgNeFHwfIhnG2q+vPRj7 KHU9aOnIUcaakS3x7UtUstN8BEHp6jrdVJM3xQiElzojceQJjqShcUo3suIS3TZKEIa/ q+wCSwmyLhAMXWit89VHrabrdm0z8JodaAn4xOccgKrSmNSXuwY7DZP8cbK9m5UDEhTA TbTSj64wO85eM1pq276rMeD9A4c5mKU+DVMlfW5NOSsvxIMd+TxOHofzx8wrdUuqQLLM 3rVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=zWt0jo8AMAZchPeNnT8VtD1Yz35B0VOWcsrzm+hetHc=; b=EPCg97zCZQzhPo/OjPa05yATVxc7UIb71QPZXrojpMtn5sQHgL8qIpvlOHmathyFvE azhRQ0ePt5HQsxOPZgYf8lZAp+mChZ3gptS1eoMIlmP/M92N9vNYuETYerEFyQEJMtlY RiTrOBnyHgvGbyntegfOrjGdxvoswFMO5ky9tzxEybw4+7thrUcWjIoNNTCVM0GuyQEJ Wz7KT0HcjazfNegtHhs3Sl6nJWc9gWjWK5dL6BA/gGlSwgaUHtEegsHtGAnPEeXSXbrd dxU+NxC5kh6vOb7MMZJfjuqQvsNHqFYrTXsFFTqjDXchKUvI8V6pajcoJ2lnX2YFwAAQ sunQ== X-Gm-Message-State: APjAAAVOOj8inEfFoJU2Ea3SEVxhPHg09lg2KwpHzjVDSEFtpX8FvLOj Chmb04qGoQ7ZqP369tTQoVmZ4r2e3raCotLwVMg= X-Google-Smtp-Source: APXvYqziAi2Y22ozLNyzPYiFdK2PgVBXM4KosDiTc3Nx+FjBq2NUFXjGLKY6H8bA/5mLr0Sx4XUxvkaoFm5l8HHo1CM= X-Received: by 2002:a50:8b9d:: with SMTP id m29mr82832052edm.248.1564150059833; Fri, 26 Jul 2019 07:07:39 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a50:b3b9:0:0:0:0:0 with HTTP; Fri, 26 Jul 2019 07:07:39 -0700 (PDT) In-Reply-To: <20190726110135.GO31381@hirez.programming.kicks-ass.net> References: <20190724191655.268628197@linuxfoundation.org> <20190724191701.954991110@linuxfoundation.org> <5D3AD35E.FB77B44F@gmail.com> <20190726110135.GO31381@hirez.programming.kicks-ass.net> From: Jari Ruusu Date: Fri, 26 Jul 2019 17:07:39 +0300 Message-ID: Subject: Re: [PATCH 4.19 079/271] x86/atomic: Fix smp_mb__{before,after}_atomic() To: Peter Zijlstra Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Linus Torvalds , Thomas Gleixner , Ingo Molnar , Sasha Levin Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/26/19, Peter Zijlstra wrote: > On Fri, Jul 26, 2019 at 01:18:06PM +0300, Jari Ruusu wrote: >> Shouldn't those clobber contraints actually be: "memory","cc" >> That is because addl subl (and other) machine instructions >> actually modify the flags register too. >> >> gcc docs say: The "cc" clobber indicates that the assembler >> code modifies the flags register. > > GCC x86 assumes any asm() will clobber "cc". No worries then. Thanks for your clarification. -- Jari Ruusu 4096R/8132F189 12D6 4C3A DCDA 0AA4 27BD ACDF F073 3C80 8132 F189