Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264002AbUDQSPt (ORCPT ); Sat, 17 Apr 2004 14:15:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264009AbUDQSPt (ORCPT ); Sat, 17 Apr 2004 14:15:49 -0400 Received: from adsl-207-214-87-84.dsl.snfc21.pacbell.net ([207.214.87.84]:30336 "EHLO lade.trondhjem.org") by vger.kernel.org with ESMTP id S264002AbUDQSPr (ORCPT ); Sat, 17 Apr 2004 14:15:47 -0400 Subject: Re: NFS and kernel 2.6.x From: Trond Myklebust To: Matthias Urlichs Cc: linux-kernel@vger.kernel.org In-Reply-To: References: <20040416011401.GD18329@widomaker.com> <1082079061.7141.85.camel@lade.trondhjem.org> <20040415185355.1674115b.akpm@osdl.org> <1082084048.7141.142.camel@lade.trondhjem.org> <20040416045924.GA4870@linuxace.com> <1082093346.7141.159.camel@lade.trondhjem.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1082225747.2580.18.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sat, 17 Apr 2004 11:15:47 -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1275 Lines: 29 On Sat, 2004-04-17 at 09:44, Matthias Urlichs wrote: > Hi, Trond Myklebust wrote: > > > As for blanket statements like the above: I have seen no evidence yet > > that they are any more warranted in 2.6.x than they were in 2.4.x. > > Oh, I saw the problem too: a slow client couldn't do full-size reads from > a fast server because the buffer on the client's network card was just 8k. Right, and this has always been a problem. I had the same issues when doing 8k reads on one of my 75MHz Pentiums some 10 years ago. The thing would more or less lock up and just pump out a constant stream of "time exceeded" ICMP messages. The NFS/RPC layer knows nothing about the existence of network cards or their buffer sizes. Only about sockets and how to read from/write to them. This sort of issue is precisely why I'd prefer to see people use TCP by default. UDP with it's dependency on fragmentation works fine on fast setups with homogeneous lossless networks. It sucks as soon as you break one of those conditions. Cheers, Trond - 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/