Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3029466pxk; Mon, 7 Sep 2020 00:34:20 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyeycMawAuXfpjFH458EgYNeyVSNZqcyPcx/gAZc8fnw5Zh+vCRy5t8iLlWa2txYZuLO4tz X-Received: by 2002:a17:906:c289:: with SMTP id r9mr15854925ejz.402.1599464060370; Mon, 07 Sep 2020 00:34:20 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1599464060; cv=none; d=google.com; s=arc-20160816; b=rzOl5rAYO1zBr+Tg8Z6JGT3WsjhiVj1iDVDSjmrrW0YBxxfggnYpQDDep0MlDx6kl7 G2/EofzoKp4RZQ3RcW1zNCTpu4uJmpdz/S64O82KW5ZwXG3tz+pW/XQK3BrVHnjPD44O x5EtnqqSaAUuQaqlTfZ/PG6LkODuHjO7AUDfNrt9oZ16PP6uv4oRCFo89XW/QM7ScxxX YXvif7V12/8TVhHhyxgEuuiQmVwrU0rK253Gg7+ZIREwlkJvA53jXYua6xTVN2FqrxO+ wqUEmPJbC2gotgJAcLRCvytCdFqoLq2Q19vNEdI09apMiW3wFsrNzl5COpzSNMkBdX1C qEEg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=a99b+NYB+iS6T18MkTOXlrL8QDqOBf/yRmUFtErwEv4=; b=TlMXBFfSdr5rX1tHxRvS9IOyec1AH2USn2VScq/zz5qM+FyIkE00FvsEx7QnKn6wrz BeJ0yS136HmGOHfoKxg3r0mzK+RbBroCmvxKmp54ozBMbcm/B5cN1inJh8z+Vb3Z8JCo gYHZ9kWlRm51TG+s1zN5u2c30eUSHznj14K+77Hyurs/+xdSk3k/ZdPCsPMf7VlxRqSu jiBSjGSizUD0DQvMz7wHyf3f4zG5pJLhJfmYba1fOx/DUbVkO12VOo4e05NXHbz3Yq1Q eskwVuycr9KLOkpBSfdn7pxuoMol5mR+Xmm74cnNb7+cjwSEbRCnjGZrAR86Y+AcsDya IUww== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id w11si2221581ejy.632.2020.09.07.00.33.58; Mon, 07 Sep 2020 00:34:20 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727004AbgIGHar (ORCPT + 99 others); Mon, 7 Sep 2020 03:30:47 -0400 Received: from verein.lst.de ([213.95.11.211]:48007 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726443AbgIGHaq (ORCPT ); Mon, 7 Sep 2020 03:30:46 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id C1B1168BFE; Mon, 7 Sep 2020 09:30:44 +0200 (CEST) Date: Mon, 7 Sep 2020 09:30:44 +0200 From: Christoph Hellwig To: Rasmus Villemoes Cc: Christoph Hellwig , arnd@arndb.de, gregkh@linuxfoundation.org, christophe.leroy@csgroup.eu, linux-kernel@vger.kernel.org Subject: Re: [PATCH] /dev/zero: also implement ->read Message-ID: <20200907073044.GE19875@lst.de> References: <20200903155922.1111551-1-hch@lst.de> <8d430999-b155-dbfa-e7db-f414b48014b1@rasmusvillemoes.dk> <20200907062026.GA19076@lst.de> <4a981ee8-2d57-c7ce-a1ca-43ad237471d2@rasmusvillemoes.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4a981ee8-2d57-c7ce-a1ca-43ad237471d2@rasmusvillemoes.dk> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 07, 2020 at 08:50:53AM +0200, Rasmus Villemoes wrote: > > Actually, while you're micro-optimizing it, AFAIK VFS already handles > count==0, It doesn't.