From owner-freebsd-hackers@FreeBSD.ORG Mon Mar 1 08:11:55 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C074816A4CE for ; Mon, 1 Mar 2004 08:11:55 -0800 (PST) Received: from smtp3b.sentex.ca (smtp3b.sentex.ca [205.211.164.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7F0CD43D41 for ; Mon, 1 Mar 2004 08:11:55 -0800 (PST) (envelope-from mike@sentex.net) Received: from avscan1.sentex.ca (avscan1.sentex.ca [199.212.134.11]) by smtp3b.sentex.ca (8.12.10/8.12.10) with ESMTP id i21GB73Z036604; Mon, 1 Mar 2004 11:11:12 -0500 (EST) (envelope-from mike@sentex.net) Received: from lava.sentex.ca (pyroxene.sentex.ca [199.212.134.18]) by avscan1.sentex.ca (8.12.10/8.12.10) with ESMTP id i21GBexa035564; Mon, 1 Mar 2004 11:11:40 -0500 (EST) (envelope-from mike@sentex.net) Received: from simian.sentex.net ([192.168.43.27]) by lava.sentex.ca (8.12.9p2/8.12.9) with ESMTP id i21GBdZa028950; Mon, 1 Mar 2004 11:11:40 -0500 (EST) (envelope-from mike@sentex.net) Message-Id: <6.0.3.0.0.20040301105700.072c4f00@209.112.4.2> X-Sender: mdtpop@209.112.4.2 (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.3.0 Date: Mon, 01 Mar 2004 11:12:07 -0500 To: Don Bowman From: Mike Tancsa In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Virus-Scanned: by amavisd-new cc: freebsd-hackers@freebsd.org Subject: RE: em0, polling performance, P4 2.8ghz FSB 800mhz X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Mar 2004 16:11:55 -0000 At 09:38 PM 29/02/2004, Don Bowman wrote: >From: Mike Tancsa [mailto:mike@sentex.net] > > At 08:44 PM 29/02/2004, Don Bowman wrote: > > >From: Mike Tancsa [mailto:mike@sentex.net] > > > > > > > > On Sat, 28 Feb 2004 23:17:44 -0500, in > > sentex.lists.freebsd.hackers > > > > > >If you want to spend more time in kernel, perhaps change > > > > > > > > > >I might have HZ @ 2500 as well. >I picked 2500 as the best for my system. Its higher than >allowed by rfc1323 and PAWS [kern/61404], but not by so much >that i anticipate a problem. Do you run the box with the supplied patch ? On the firewall device I was thinking of experimenting with, I do have long TCP sessions that it sounds like HZ=2500 would break. >For my target packets per second >rate, it means that i can use a reasonable number of dma >descriptors. I found that bridging performance in particular >needs the higher hz to avoid dropping packets, to improve >its performance. In terms of fiddling with the em tunables, what are the drawbacks of moving from 256 to 512 on EM_MAX_TXD EM_MAX_RXD >more buffers == better ability to handle latency >bursts, but worse for cache occupancy. Buffers as is net.inet.ip.intr_queue_maxlen ? Thanks, ---Mike