From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262258AbVG2DvU (ORCPT ); Thu, 28 Jul 2005 23:51:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262262AbVG2DvU (ORCPT ); Thu, 28 Jul 2005 23:51:20 -0400 Received: from smtp.osdl.org ([65.172.181.4]:38028 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S262258AbVG2DvT (ORCPT ); Thu, 28 Jul 2005 23:51:19 -0400 Date: Thu, 28 Jul 2005 20:50:16 -0700 From: Andrew Morton To: Andrey Borzenkov Cc: linux-kernel@vger.kernel.org Subject: Re: Syncing single filesystem (slow USB writing) Message-Id: <20050728205016.1bdf7288.akpm@osdl.org> In-Reply-To: <200507290731.32694.arvidjaar@mail.ru> References: <200507290731.32694.arvidjaar@mail.ru> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrey Borzenkov wrote: > > Mandrake always mounted USB sticks with sync option; it was effectively noop > except for a patch that implemented limited dsync semantic. > > Now, when full sync support for FATis in kernel, moutning with sync became > real pain. Writing speed dropped from 3MB/s to 30KB/s in my case (and I am > not alone). Unfortunately I think we're just going to have to live with that. It is right that fatfs behaves as it does, and unfortunate that some distros will operate slowly. For reference: how does mandrake implement this? Just in /etc/fstab? How should we tell other people to fix this? > One idea how to improve situation - continue to mount with dsync (having > basically old case) and do frequent sync of filesystem (this culd be started > as HAL callout or whatever). Unfortunately, I could not find a way to request > a sync (flush) of single mount point or block device. Have I missed > something? It's trivial to do in-kernel but no, I'm afraid there isn't a userspace interface for this.