From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759949AbXGTKQT (ORCPT ); Fri, 20 Jul 2007 06:16:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753209AbXGTKQK (ORCPT ); Fri, 20 Jul 2007 06:16:10 -0400 Received: from wr-out-0506.google.com ([64.233.184.234]:31018 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752447AbXGTKQI (ORCPT ); Fri, 20 Jul 2007 06:16:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=h8IiHhYaPFZBhMPDEV/I5lGeGbP9XsLs0ZqKXOyWfyScRpaUp2xFsuyzDnywgxKf+e+yvIw5wdgwBGnQHiIvCgMPpBxFF9hB6DELm3uVvSP0H/9Q7eIVrd8RRbehSj31cLMWEFwzYWcmeRw0nfkAvyYooT+HvOe7x8mB9E+VjaI= Message-ID: Date: Fri, 20 Jul 2007 10:16:05 +0000 From: "Dave Young" To: "rae l" Subject: Re: [PATCH] fs/fuse/dev.c: use zero_user_page instead Cc: "Miklos Szeredi" , fuse-devel@lists.sourceforge.net, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org In-Reply-To: <91b13c310707200312j17ec110bm20c100e5861b1758@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <11849242706-git-send-email-crquan@gmail.com> <91b13c310707200312j17ec110bm20c100e5861b1758@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >On 7/20/07, rae l wrote: > On 7/20/07, Dave Young wrote: > > > - if (page && zeroing && count < PAGE_SIZE) { > > > - void *mapaddr = kmap_atomic(page, KM_USER1); > > > - memset(mapaddr, 0, PAGE_SIZE); > > > - kunmap_atomic(mapaddr, KM_USER1); > > > - } > > > + if (page && zeroing && count < PAGE_SIZE) > > > + zero_user_page(page, 0, PAGE_SIZE, KM_USER1); > > Why clear all page? IMHO,only count bytes need to be cleared. > The original one is memset(mapaddr, 0, PAGE_SIZE), namely clear the whole page. Yes, I have same suspicion with original code. > > -- > Denis Cheng > Linux Application Developer > > "One of my most productive days was throwing away 1000 lines of code." > - Ken Thompson. >