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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C012CC433EF for ; Mon, 27 Sep 2021 12:52:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A21C3610A2 for ; Mon, 27 Sep 2021 12:52:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234457AbhI0Mxy (ORCPT ); Mon, 27 Sep 2021 08:53:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234360AbhI0Mxx (ORCPT ); Mon, 27 Sep 2021 08:53:53 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80B7CC061575 for ; Mon, 27 Sep 2021 05:52:15 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id d13-20020a17090ad3cd00b0019e746f7bd4so10063309pjw.0 for ; Mon, 27 Sep 2021 05:52:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=uwRoL4vai1J0WCVDQj2ZNZYEe4M117wFeqCni6D+v3E=; b=lIuP9Ea+24LNri1ZcHUdW/tVNQU6hgWf3lQMcY95jfTE1wQGynD3ga2bdh/5fiQFZc UUVP09bfDPEFimluS++Fl83/d7CDJgAlCM6s2z9A75bueSCVTgNWHl4oDxPmwheDxSrJ Wz4rskU73WgwwIMLriyk9Mo2xpBQ7lBLVWb27Y1T4fgQ3oWzDh8Axg8kb5DKTIX+UKLd oi1lw4uIBnBQkrcXQeGnF1Ux5oyeuTG4aLdnNllda7WUUgOAXxq2nbJix5fZik9fKOYh rB0QzqnBDqd26WDp4QwvOlBSNkkhWGWNml55lp4lVYIio878F2uYtU2DVae0i8gkOoAB qyBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=uwRoL4vai1J0WCVDQj2ZNZYEe4M117wFeqCni6D+v3E=; b=f3uPWYyWI1iy0HZ7DhDY+PTSVS3npPmDsjR9bF2RijPbxG78zVpn812eLT1oYueIxd SJze3pyfOtCvT750mfA8n2P+IkNkQGATRhYrg7IqPm59uUC6X91x6cicNXoaunTfRZuc Q+2HZJz14PjZIvGtWpaDyBFSLDJOdcosWkO2p06vviSzpHOXMj6kWlxCVufk26PM4Nif uP22UkVGmt0Gg/PzsfsW+zYiz47OHy2Ktu2azuZzjvhesgm/Fy80vOQ0s9YNf05Q9fpT srzTc6HoHSHHUNkEaAFea1Uo5rHDcOQW2M0r+OGMfGMjlLfi6RoJId9PViXg//facVSj xAcQ== X-Gm-Message-State: AOAM531OlFXeTBno2W0kWkwbwERVdfbqJxUeR+gzlIpTN1nPRdFlMkKK JY804vqYhG0Uzm1KAnj/fgU= X-Google-Smtp-Source: ABdhPJx7Pg/Umy0XcsNCFDGYkPG5X0aJOG/Q6pDcZTE/qrvym6KCK3DQx7zD0+9QBdbYAzi4puEBhw== X-Received: by 2002:a17:90a:8810:: with SMTP id s16mr8581927pjn.7.1632747134920; Mon, 27 Sep 2021 05:52:14 -0700 (PDT) Received: from smtpclient.apple (c-24-6-216-183.hsd1.ca.comcast.net. [24.6.216.183]) by smtp.gmail.com with ESMTPSA id q18sm17715537pfj.46.2021.09.27.05.52.13 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Sep 2021 05:52:14 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.13\)) Subject: Re: [RFC PATCH 2/8] mm/madvise: remove unnecessary check on madvise_dontneed_free() From: Nadav Amit In-Reply-To: <20210927121902.r5gslag4nvvseoxo@box> Date: Mon, 27 Sep 2021 05:52:12 -0700 Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Xu , Andrea Arcangeli , Minchan Kim , Colin Cross , Suren Baghdasarya , Mike Rapoport Content-Transfer-Encoding: quoted-printable Message-Id: <8ACD5AC6-2235-4A62-8044-F686EB26840E@gmail.com> References: <20210926161259.238054-1-namit@vmware.com> <20210926161259.238054-3-namit@vmware.com> <20210927091143.tn6ediykqycu6rtu@box.shutemov.name> <20210927121902.r5gslag4nvvseoxo@box> To: "Kirill A. Shutemov" X-Mailer: Apple Mail (2.3654.120.0.1.13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Sep 27, 2021, at 5:19 AM, Kirill A. Shutemov = wrote: >=20 > On Mon, Sep 27, 2021 at 04:05:47AM -0700, Nadav Amit wrote: >> Having said that, if you want, I can turn this condition into >> WARN_ON_ONCE() or VM_BUG_ON(), although I really see no reason to >> do so. >=20 > BUILD_BUG() should be fine here. It does not work. At least my gcc is not smart enough to figure it out in build time. I can put instead: BUILD_BUG_ON(__builtin_constant_p(behavior)); for potentially smarter compilers (clang?), but I doubt it would work.