Date: Sun, 25 Mar 2001 13:03:31 -0600 (CST) From: Ryan Thompson <ryan@sasknow.com> To: j mckitrick <jcm@FreeBSD-uk.eu.org> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: interpreting 'load' statistics Message-ID: <Pine.BSF.4.21.0103251220010.99384-100000@ren.sasknow.com> In-Reply-To: <20010325181304.A31661@dogma.freebsd-uk.eu.org>
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j mckitrick wrote to freebsd-questions@FreeBSD.ORG: > > When you run 'w' or 'uptime', how can you interpret the load > statistics? I always thought under 1 was okay. I read that somewhere > but now I'm not so sure. I have a system that routinely runs between 2.0 and 4.0 with no slowdown most of the time. I've seen systems running at around 0.2 or 0.3 that are barely useable. The "load average" function (see getloadavg(3)) is basically just an indication of the average number of processes in the run queue, for the last 1, 5, and 15 minutes. If the processes are lightweight, don't use much CPU, memory, disk, etc., you can start up quite a few without a hit. Starting, say, one large X application... Your load average won't move much, but your system will sure slow down momentarily! Stupid Programming Exercise (don't do this on your employer's computer): Make a fork bomb. Run the fork bomb AS A NORMAL USER. As root, run uptime. Kill the fork bomb. ryan@stimpy$ uptime 1:01PM up 91 days, 10:17, 3 users, load averages: 572.68, 607.01, 388.05 What can I say... I know how to hose a system :-) NB: Actually, the work I did to get you the above output prompted a weird kind of fork bomb that was hard as hell to kill without rebooting... Maybe I'll document the fix and refine that into a PR :-) > > jm > -- Ryan Thompson <ryan@sasknow.com> Network Administrator, Accounts SaskNow Technologies - http://www.sasknow.com #106-380 3120 8th St E - Saskatoon, SK - S7H 0W2 Tel: 306-664-3600 Fax: 306-664-1161 Saskatoon Toll-Free: 877-727-5669 (877-SASKNOW) North America To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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