From owner-freebsd-hackers Fri Nov 15 06:02:38 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id GAA14662 for hackers-outgoing; Fri, 15 Nov 1996 06:02:38 -0800 (PST) Received: from casparc.ppp.net (casparc.ppp.net [194.64.12.35]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id GAA14633; Fri, 15 Nov 1996 06:02:25 -0800 (PST) Received: from ernie by casparc.ppp.net with uucp (Smail3.1.28.1 #1) id m0vOOqI-000I9vC; Fri, 15 Nov 96 15:02 MET Received: by ernie.kts.org (Smail3.1.29.1 #5) id m0vOMhn-00001bC; Fri, 15 Nov 96 12:45 MET Message-Id: From: hm@kts.org (Hellmuth Michaelis) Subject: Re: userland PPP giving weird load numbers To: msmith@atrad.adelaide.edu.au (Michael Smith) Date: Fri, 15 Nov 1996 12:45:06 +0100 (MET) Cc: hm@kts.org, kelly@fsl.noaa.gov, mark@quickweb.com, hackers@FreeBSD.org, current@FreeBSD.org In-Reply-To: <199611150756.SAA06861@genesis.atrad.adelaide.edu.au> from "Michael Smith" at Nov 15, 96 06:26:01 pm Organization: Kitchen Table Systems Reply-To: hm@kts.org X-Mailer: ELM [version 2.4 PL24] Content-Type: text Sender: owner-hackers@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > > > I see this too all the time, from 2.0.5 all the way to 2.1.5. While > > > /usr/sbin/ppp is running, the load average hangs around 1.0. Sometimes, > > > it'll drop. It's odd ... it's usually when ppp is idle that it hangs > > > around 1.0. > > > > I had this phenomenon too - but NOT with ppp. An isdn userland daemon i am > > working on showed this exact behaviour; when it was running, the system load > > was constantly 1.0 or very nearby. This all is under 2.1.5 (and 2.1 too). > > The process wasn't doing anything (or very little). > > But what _was_ it supposed to be doing? Ok, when this happened, the daemon was in a tight read() loop, where the read() timed out every second in the driver. Basically after implementing select() in the driver and using that with a one second timeout made the problem go away. In the whole application several one second timeouts exists at several drivers in the kernel - i'm quite shure there is a problem with something like several timeouts timing out simultaneously causing something. I just ran out of ideas where to search for and what to search for so i stopped looking for the real problem. But i'm able to reproduce it. hellmuth -- Hellmuth Michaelis hm@kts.org Hamburg, Europe (A)bort, (R)etry, (I)nstall BSD ? -------------------------------------------------------------------------------- kts.org will move and will be not available from November 20th for 10 days --------------------------------------------------------------------------------