Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261722AbVCGJXv (ORCPT ); Mon, 7 Mar 2005 04:23:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261721AbVCGJWp (ORCPT ); Mon, 7 Mar 2005 04:22:45 -0500 Received: from ns1.lanforge.com ([66.165.47.210]:50083 "EHLO www.lanforge.com") by vger.kernel.org with ESMTP id S261709AbVCGJWe (ORCPT ); Mon, 7 Mar 2005 04:22:34 -0500 Message-ID: <422C1D57.9040708@candelatech.com> Date: Mon, 07 Mar 2005 01:22:31 -0800 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.7.3) Gecko/20041020 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Nick Piggin CC: Christian Schmid , linux-kernel@vger.kernel.org Subject: Re: BUG: Slowdown on 3000 socket-machines tracked down References: <4229E805.3050105@rapidforum.com> <422BAAC6.6040705@candelatech.com> <422BB548.1020906@rapidforum.com> <422BC303.9060907@candelatech.com> <422BE33D.5080904@yahoo.com.au> In-Reply-To: <422BE33D.5080904@yahoo.com.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1684 Lines: 55 Nick Piggin wrote: > Ben Greear wrote: > >> Christian Schmid wrote: >> >>> Ben Greear wrote: > > >>>> How many bytes are you sending with each call to write()/sendto() >>>> whatever? >>> >>> >>> >>> I am using sendfile-call every 100 ms per socket with the poll-api. >>> So basically around 40 kb per round. >> >> >> >> My application is single-threaded, uses non-blocking IO, and >> sends/rcvs from/to memory. >> It will be a good test of the TCP stack, but will not use the sendfile >> logic, >> nor will it touch the HD. >> > > I think you would have better luck in reproducing this problem if you > did the full sendfile thing. > > I think it is becoming disk bound due to page reclaim problems, which > is causing the slowdown. > > In that case, writing the network only test would help to confirm the > problem is not a networking one - so not useless by any means. It's not trivial to write something like this :) I'll be using something I already have. If I can't reproduce the problem, then perhaps it is due to sendfile and someone can write a customized test. The main reason I offered is because people are ignoring the bug report for the most part and asking for a test case. I may be able to offer an independent verification of the problem which might convince someone to write up a dedicated test case... Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com - 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/