From owner-freebsd-hackers Mon Aug 7 14: 8:18 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by hub.freebsd.org (Postfix) with ESMTP id 1F72137B50F for ; Mon, 7 Aug 2000 14:08:14 -0700 (PDT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (robert@fledge.pr.watson.org [192.0.2.3]) by fledge.watson.org (8.9.3/8.9.3) with SMTP id RAA03430; Mon, 7 Aug 2000 17:08:01 -0400 (EDT) (envelope-from robert@fledge.watson.org) Date: Mon, 7 Aug 2000 17:08:01 -0400 (EDT) From: Robert Watson X-Sender: robert@fledge.watson.org To: Dennis Cc: hackers@freebsd.org Subject: Re: FreeBSD belly up with big config In-Reply-To: <200008051708.NAA00486@etinc.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 5 Aug 2000, Dennis wrote: > With 1800 interfaces in the system Freebsd seems to use about 50Mhz of cpu > when idle in "interrupts" even when there are no interrupts to process. on > a 500Mhz box it uses 10% of the cpu and it seems linear with different > speed processors. > > the 1800 interfaces are 900 DLCIs on a T3 frame with 900 bridge groups > (rather common for a DSL delivered via Frame). This with just one > line...the same problem could occur with say 8 T1 lines with 100+ DLCIs on > each. > > It seems that there is substantial overhead just scanning interfaces for > some routine maintenance...is there any hope of alleviating this deboggle? I'd made some similar observations about the current lack of scalability both in management of (struct ifnet) chains, and mountpoints in the file system. As we move to a more dynamic network environment, a lot of things about ifnet handling need to be improved, including fixing (really fixing) the freeing of struct ifnet (lots of loose mbuf pointers hanging around to the struct ifnet, as well as stuff in filtering rules, et al). The bridging code isn't currently designed to work in this manner, and also has problems with dynamically introduced interfaces (try and use options BRIDGE and the sysctl enabled with a pccard sometime). Robert N M Watson robert@fledge.watson.org http://www.watson.org/~robert/ PGP key fingerprint: AF B5 5F FF A6 4A 79 37 ED 5F 55 E9 58 04 6A B1 TIS Labs at Network Associates, Safeport Network Services To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message