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=-15.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL 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 282B1C43381 for ; Wed, 6 Jan 2021 20:19:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06B7E22CAF for ; Wed, 6 Jan 2021 20:19:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727910AbhAFUTa (ORCPT ); Wed, 6 Jan 2021 15:19:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726730AbhAFUT2 (ORCPT ); Wed, 6 Jan 2021 15:19:28 -0500 Received: from mail-ot1-x32b.google.com (mail-ot1-x32b.google.com [IPv6:2607:f8b0:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8211C061575 for ; Wed, 6 Jan 2021 12:18:47 -0800 (PST) Received: by mail-ot1-x32b.google.com with SMTP id i6so4229578otr.2 for ; Wed, 06 Jan 2021 12:18:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=iJJgoSbyLyAY5ybGUsqGtrthU9HgytjNnp54LxffTUQ=; b=n18YKI9jp+HXb5AmIc1F8DYthoi2MZWrs68850q3/7Y1oC2mbTRPxOlZKOAueyliX7 1I5V8B8dipw2MlR3de+e6ly9CXjr/nMkUgI5+KEQmPS0qGpgAyWM7/kTtnpHJdkdVZrS 9HQeY5ROuADlcLJa7VXZC1o9PoWzHpZ8czJhuXEWT6FmoTC4ZLuGma8j0KowQGnJsgRx oKHoUWktsvyUZa+6guYPI+pf0knN1C44eNG0sAXIdn7OhDq0xgRjKAJcc4vYqmVt3y6b WU8dm/lEz2rKL+6FwmdiJYILhZKWEfV9Jqwim4FFwyOBhyxSN0FQYDKe0YkaqtSW8tS8 pm8A== 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:in-reply-to:message-id :references:user-agent:mime-version; bh=iJJgoSbyLyAY5ybGUsqGtrthU9HgytjNnp54LxffTUQ=; b=UzX/0GHa+P7dqm7Y9g15NRHNa0YgkAePpzEJ4lm6ClUh24ZNeehK08cdUT8Qpiqewz /qmYhvgPwLijPMxkJoRMqflwMVrUDPzaYN2XezVV+9uGe9k8d3qvoMYFUUSDHGVhll1E n00tkkKKKiEXaCx4BfKx/M7zULzEYSh7fS6phy7NO4hoOjWcqoJBI6FOOCaYAFN2Gbqi Z/KBsoN9BnJGuPBlgxnFfJ/EHOTwYPiiPK4kRQRn+IzQpBr0QI9Lw7jUQbSaPso+dHiO zj+LmAqCOxwSZDvhzgUjaTptb78OleH9YYUFkGVMhAf0K6zGkcxoTFSNO3QplEDpYmvo AQIg== X-Gm-Message-State: AOAM531Dc3EyHsulUKLLydbWnCV8zpiygS1WLqNQBtw3y8T4qC/ECc9D Z+KySganM4bKuTVfPFPtLPeP0A== X-Google-Smtp-Source: ABdhPJwDmJwX/5sniqT/j0TdQ+RiDKq/oekQVIbn0+XlvLry2PSCbGsfXnjr0wqRhpON+IiPk/nRpA== X-Received: by 2002:a05:6830:20c2:: with SMTP id z2mr4305329otq.322.1609964327126; Wed, 06 Jan 2021 12:18:47 -0800 (PST) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id y84sm820819oig.36.2021.01.06.12.18.46 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Wed, 06 Jan 2021 12:18:46 -0800 (PST) Date: Wed, 6 Jan 2021 12:18:36 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrea Arcangeli cc: Andrew Morton , Hugh Dickins , Alex Shi , Minchan Kim , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/mmap: replace if (cond) BUG() with BUG_ON() In-Reply-To: Message-ID: References: <1607743586-80303-1-git-send-email-alex.shi@linux.alibaba.com> <1607743586-80303-2-git-send-email-alex.shi@linux.alibaba.com> <20210106114620.5c221690f3a9cad7afcc3077@linux-foundation.org> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 6 Jan 2021, Andrea Arcangeli wrote: > > I'd be surprised if the kernel can boot with BUG_ON() defined as "do > {}while(0)" so I guess it doesn't make any difference. I had been afraid of that too, when CONFIG_BUG is not set: but I think it's actually "if (cond) do {} while (0)".