Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267543AbUIFNgS (ORCPT ); Mon, 6 Sep 2004 09:36:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268011AbUIFNgR (ORCPT ); Mon, 6 Sep 2004 09:36:17 -0400 Received: from mail.fh-wedel.de ([213.39.232.194]:4496 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S267543AbUIFNgQ (ORCPT ); Mon, 6 Sep 2004 09:36:16 -0400 Date: Mon, 6 Sep 2004 15:35:23 +0200 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Gunnar Ritter Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] copyfile: generic_sendpage Message-ID: <20040906133523.GC25429@wohnheim.fh-wedel.de> References: <20040904165733.GC8579@wohnheim.fh-wedel.de> <20040904153902.6ac075ea.akpm@osdl.org> <413C5BF2.nail2RA1138AG@pluto.uni-freiburg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <413C5BF2.nail2RA1138AG@pluto.uni-freiburg.de> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1382 Lines: 29 On Mon, 6 September 2004 14:45:38 +0200, Gunnar Ritter wrote: > > It is an even more serious problem in my experience. I have been > using sendfile() in my cp command at > for quite some time, and I quickly decided to send files separated in > some decently sized blocks. Otherwise if a whole file is sent at once > and the source file is e.g. on an uncached floppy disk, cp will become > uninterruptible for about a minute, which is a serious usability flaw. > The user might discover that he is copying the wrong file, or he might > simply change his mind and like to abort the copy or whatever. A > performance gain of only 10 % is neglegible in comparison to this > problem. Thus I think if copyfile() would not be interruptible by SIGINT > and friends, its practical value would be quite limited. Using a loop of 4k sendfile commands should be easy enough to do. Problem is that copyfile(2) should do some decent cleanup after receiving a signal. Hans Reiser got it right that all filesystem operations should be atomic. J?rn -- Premature optimization is the root of all evil. -- Donald Knuth - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/