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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 3CE55C2BB84 for ; Mon, 7 Sep 2020 07:30:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0FD120757 for ; Mon, 7 Sep 2020 07:30:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727103AbgIGHar (ORCPT ); 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.