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 BC35BC433F5 for ; Mon, 27 Sep 2021 09:11:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2DF860F44 for ; Mon, 27 Sep 2021 09:11:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233633AbhI0JN0 (ORCPT ); Mon, 27 Sep 2021 05:13:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233519AbhI0JNY (ORCPT ); Mon, 27 Sep 2021 05:13:24 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 236D6C061575 for ; Mon, 27 Sep 2021 02:11:46 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id b20so74565926lfv.3 for ; Mon, 27 Sep 2021 02:11:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=WjdgfNID1F56pN/ToVuugx7UPq8+diudyxoBfhqPDek=; b=CZ0INnd+an0mI0YdfzuS/n5CtlqpiQBbC3XKcsLZ6DET1fsm18OachI2raiJmeEDZn mo2U8zBEjNExo9Bfm/u8YK2XOajIDPBbTzwblyvny/q2O/Ns4eFcU9ctYWg+BvZTxXxQ 4BQQDihSMkbr6f+DY31NKdXMMac3XLQQ7O5oOxyFbKHjfCqU+5aLHJDQMIaQ4nVsgjyQ awRjzp57HaD0/hZ56iHukLLMdysVUvUCrlPVxQQBSt+7eh2HKG/ejW5LWfT2WrGpDaWH QNMxbKmPrDZzF4s9CE4h9PvmjtaVeQ1hx5Fo7zHQPqv3hIaXv6INnP/EoHbwBBU7jwc0 EYNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=WjdgfNID1F56pN/ToVuugx7UPq8+diudyxoBfhqPDek=; b=LERTEBW49RlCk7OGSroXHRcZj8UfXddHParMQFCejMflBe4M7cBBEh96jFlEdVL5+H zFvbIrt+JO/OzRRjjKWhBDYJGl4+cdrw7+I2fAiAFP7aFiApvktLp/cb5eOtG+GhGSl8 VQHTM3Cd/fvm1TJeM4NUS4xXsDPluUVL4aWhj3Wa1p6NbFBr7Dqxise4k0HVy+Fh0SvI HsPoN3ZCpID3XE1qcnufMMw5PwXZievMCM3eEalP/PCFvoq45yRqgUB3fi9TT3SUQUwn yMvRjftdD//Qqism94VlAmjsDcZTaFQdKYZYz7Q1S7+nszjIzBniNWmG0myWVzn08cna QxGQ== X-Gm-Message-State: AOAM530zpYnava5FDLuLXrZxN27MsTVZx+g8AAizf25EmRjWhbaQAss/ I1Le2+68C4VplfxwfUlhImEYVl/3qlunwQ== X-Google-Smtp-Source: ABdhPJxOl9/7WzKIWOyEWXlwozmClPTfR7YGpoRlSDC00W0KLvRODwhCKeBhnaXXhi6/XbkebyxQZA== X-Received: by 2002:a05:6512:b81:: with SMTP id b1mr23370847lfv.301.1632733904548; Mon, 27 Sep 2021 02:11:44 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id d16sm1526937lfg.138.2021.09.27.02.11.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Sep 2021 02:11:43 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 4D17910306C; Mon, 27 Sep 2021 12:11:43 +0300 (+03) Date: Mon, 27 Sep 2021 12:11:43 +0300 From: "Kirill A. Shutemov" To: Nadav Amit Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Xu , Nadav Amit , Andrea Arcangeli , Minchan Kim , Colin Cross , Suren Baghdasarya , Mike Rapoport Subject: Re: [RFC PATCH 2/8] mm/madvise: remove unnecessary check on madvise_dontneed_free() Message-ID: <20210927091143.tn6ediykqycu6rtu@box.shutemov.name> References: <20210926161259.238054-1-namit@vmware.com> <20210926161259.238054-3-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210926161259.238054-3-namit@vmware.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 26, 2021 at 09:12:53AM -0700, Nadav Amit wrote: > From: Nadav Amit > > madvise_dontneed_free() is called only from madvise_vma() and the > behavior is always either MADV_FREE or MADV_DONTNEED. There is no need > to check again in madvise_dontneed_free() if the behavior is any > different. So what. The check is free. Compiler should be clever enough to eliminate the additional check. If there's a new MADV_DONTNEED flavour, the change would have to be effectively reverted. NAK. -- Kirill A. Shutemov