From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 22 Jan 2001 18:39:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 22 Jan 2001 18:39:18 -0500 Received: from zeus.kernel.org ([209.10.41.242]:17126 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Mon, 22 Jan 2001 18:37:39 -0500 Date: Mon, 22 Jan 2001 15:36:38 -0800 From: "H . J . Lu" To: Trond Myklebust Cc: Linux Kernel , NFS maillist , Michael Kriss Subject: Re: [NFS] [CFT] Improved RPC congestion handling for 2.4.0 (and 2.2.18) Message-ID: <20010122153638.B32449@valinux.com> In-Reply-To: <14904.54852.334762.889784@charged.uio.no> <20010122143740.A31589@valinux.com> <14956.48013.908491.509166@charged.uio.no> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <14956.48013.908491.509166@charged.uio.no>; from trond.myklebust@fys.uio.no on Tue, Jan 23, 2001 at 12:00:29AM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 23, 2001 at 12:00:29AM +0100, Trond Myklebust wrote: > >>>>> " " == H J Lu writes: > > > I got a report which indicates it may not be a good idea, > > especially for UDP. Suppose you have a lousy LAN or NFS UDP > > server for whatever reason, some NFS/UDP packets may get lost > > very easily while a ping request may get through. In that case, > > the rpc ping may slow down the NFS client over UDP > > significantly. > > Hi HJ, > > Could you clarify this? Don't forget that we only send the ping after > a major timeout (usually after 3 or more resends). > > IOW: If the ping gets through, then it'll have cost us 1 RPC request, > which is hardly a major contribution when talking about timescales of > the order of 5 seconds which is what that major timeout will have cost > (Don't forget that RPC timeout values increase geometrically). > Michael Kriss is having this problem. I think this problem may be very specific to his network setup. I couldn't duplicate his problem. My guess is for his case, every ping sent is a loss of a potential working retry packet. He is using Solaris NFS sever with Linux client. I had an impression that packets from Solaris NFS server was dropped quite often. I don't know what happened. -- H.J. Lu (hjl@valinux.com) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/