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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 84378CA9EBC for ; Thu, 24 Oct 2019 13:43:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59B2E21872 for ; Thu, 24 Oct 2019 13:43:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="WemCD9We" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393703AbfJXNn2 (ORCPT ); Thu, 24 Oct 2019 09:43:28 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:36081 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393656AbfJXNn1 (ORCPT ); Thu, 24 Oct 2019 09:43:27 -0400 Received: by mail-wm1-f66.google.com with SMTP id c22so2671207wmd.1; Thu, 24 Oct 2019 06:43:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=FGm/Y7V816AbGprOQHUkgpBjccypqHGHqD5N/dMxVkw=; b=WemCD9WeMOlk2CrvosRt1hMf4Lxem6lm1hZUuyoJj0K6NGWgX+19cYcBRdqNTF1ixs nlh1LJY5VZtICct6frTaqVEVQql6wmU2dSjd6C3zNeiwgELILHPNudrwZvNdIlVDEPLq BJ73ykuJ+94u4uQBPNyV6tMgo0+ZUCp+bITF5QywIsdfDdC7jUIdAE17pFsc36PxQ4xV vTCReHMAJl8u78OBLKl+EAV7iyvexnZ1AhZoSIYgkKHBhwgYVLTcTBZkhYdtjrBMVgMm QjtxBqDMzT3+wxvIx9QrBTJjUHsuCvdPR3l7fqri3ZZWQX/SN7CDxmP1Gcl/uWO84fe1 4Lgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=FGm/Y7V816AbGprOQHUkgpBjccypqHGHqD5N/dMxVkw=; b=i4lX+0Oc7ue6+81NUA8GZE/BHEtuP+L/IdnPtVmBAncwlFhQvzkutC5jEEA1QDX81B 0CQfh7yu9zCxJh8FCd6ZsXqNH0pMG40lsJKgkt4Iuc+fVl/R/JXqCWYDuVvAdt7wz0PM esbIwRz8vXWKIeNCpPrXs9jVIl2ER6NWpaVcJ9YaIpoHWokjfJngU07SkrZoOsfenlyH TV/HSHGB4UNMas6vEa3nC1ob2SxGwh4ygZq9Ro1o6J8lY9zGMHQNEH2uquwZAqM0U3ek c6way7LGxSiv2n5en8OWif332jn23Ugrdqa0G1AbiSycPDf5KoGDypL49mCdBFIYykbT xotA== X-Gm-Message-State: APjAAAW0kvt/Kphgd1ouWfEbFhC9FkPjPavkrPiCrFNsSRUc9k2vn7YZ BDoSANhk70t1kYwCa4Ig4h4= X-Google-Smtp-Source: APXvYqzOXOUeSsq0bKR1Uijb/ZiwdTPLXJEsLwvGyotcdrS+xtT/7Fg0PiKSxgnSjNVkIwYqOuYnSQ== X-Received: by 2002:a7b:cd19:: with SMTP id f25mr5273390wmj.154.1571924605222; Thu, 24 Oct 2019 06:43:25 -0700 (PDT) Received: from andrea.guest.corp.microsoft.com ([2a01:110:8012:1012:e185:86b0:69d4:5ba5]) by smtp.gmail.com with ESMTPSA id o6sm15323168wrx.89.2019.10.24.06.43.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Oct 2019 06:43:24 -0700 (PDT) Date: Thu, 24 Oct 2019 15:43:19 +0200 From: Andrea Parri To: Dmitry Vyukov Cc: Christian Brauner , Will Deacon , LKML , bsingharora@gmail.com, Marco Elver , stable , syzbot , syzkaller-bugs Subject: Re: [PATCH v6] taskstats: fix data-race Message-ID: <20191024134319.GA12693@andrea.guest.corp.microsoft.com> References: <20191009114809.8643-1-christian.brauner@ubuntu.com> <20191021113327.22365-1-christian.brauner@ubuntu.com> <20191023121603.GA16344@andrea.guest.corp.microsoft.com> <20191024113155.GA7406@andrea.guest.corp.microsoft.com> <20191024130502.GA11335@andrea.guest.corp.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 > But why? I think kernel contains lots of such cases and it seems to be > officially documented by the LKMM: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/memory-model/Documentation/explanation.txt > address dependencies and ppo Well, that same documentation also alerts about some of the pitfalls developers can incur while relying on dependencies. I'm sure you're more than aware of some of the debate surrounding these issues. Andrea