From owner-freebsd-hackers Sat Mar 8 5: 8:27 2003 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 1596037B401 for ; Sat, 8 Mar 2003 05:08:26 -0800 (PST) Received: from grassmarket.ucs.ed.ac.uk (grassmarket.ucs.ed.ac.uk [129.215.166.64]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4558A43F75 for ; Sat, 8 Mar 2003 05:08:24 -0800 (PST) (envelope-from bruce@cran.org.uk) Received: from fourtytwo.brucec.backnet (12266209.resnet.ed.ac.uk [10.6.0.100] (may be forged)) by grassmarket.ucs.ed.ac.uk (8.11.6/8.11.6) with ESMTP id h28D8AT00833; Sat, 8 Mar 2003 13:08:21 GMT Received: from fourtytwo.brucec.backnet (localhost.fourtytwo.brucec.backnet [127.0.0.1]) by fourtytwo.brucec.backnet (8.12.8/8.12.6) with ESMTP id h28D8AVY005274; Sat, 8 Mar 2003 13:08:10 GMT (envelope-from bruce@fourtytwo.brucec.backnet) Received: (from bruce@localhost) by fourtytwo.brucec.backnet (8.12.8/8.12.8/Submit) id h28D8Alr005273; Sat, 8 Mar 2003 13:08:10 GMT Date: Sat, 8 Mar 2003 13:08:10 +0000 From: Bruce Cran To: Terry Lambert Cc: hackers@freebsd.org Subject: Re: High CPU usage when forwarding packets Message-ID: <20030308130810.GA5234@fourtytwo.brucec.backnet> References: <20030307131038.GA919@fourtytwo.brucec.backnet> <3E68EBCF.E19242C1@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3E68EBCF.E19242C1@mindspring.com> User-Agent: Mutt/1.5.3i Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, Mar 07, 2003 at 10:58:23AM -0800, Terry Lambert wrote: > Bruce Cran wrote: > > Also, I'm getting > > several thousand 'lnc0: Missed packet -- no receive buffer' messages. > > Could this be the problem, or is the system just not powerful enough do > > nat? The sis0 card is 100MBit PCI, while the lcn0 is 10MBit ISA. > > The "no receive buffers available" message happens when the > system runs out of mbufs. > > There are a lot of reasons this could happen, but the proximal > cause is you didn't tune the number NMBCLUSTERS, et. al. high > enough. You should try rebuilding your kernel with a larger > number. > > If the problem still happens, you need to do a "netstat -a > x", > and then look for large numbers in the "Recv-Q" and "Send-Q" > columns, and then figure out what's causing them. > Thanks, I added kern.ipc.nmbclusters=8192 to /boot/loader.conf and the messages have stopped. I have also learnt that the high CPU usage is simply because I'm trying to push 600KB/sec over an ISA bus, and lots of copying is going on. I'd like to get a PCI card and stop using the onboard lnc, but unfortunately the single PCI slot is already taken up by other other NIC. Bruce Cran To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message