From owner-freebsd-stable Sat Jan 8 18: 6:22 2000 Delivered-To: freebsd-stable@freebsd.org Received: from dorifer.heim3.tu-clausthal.de (dorifer.heim3.tu-clausthal.de [139.174.243.252]) by hub.freebsd.org (Postfix) with ESMTP id 9BAC214E44; Sat, 8 Jan 2000 18:06:17 -0800 (PST) (envelope-from olli@dorifer.heim3.tu-clausthal.de) Received: (from olli@localhost) by dorifer.heim3.tu-clausthal.de (8.9.3/8.9.3) id DAA75669; Sun, 9 Jan 2000 03:06:15 +0100 (CET) (envelope-from olli) Date: Sun, 9 Jan 2000 03:06:15 +0100 (CET) Message-Id: <200001090206.DAA75669@dorifer.heim3.tu-clausthal.de> From: Oliver Fromme To: freebsd-stable@FreeBSD.ORG, freebsd-current@FreeBSD.ORG Reply-To: freebsd-stable@FreeBSD.ORG, freebsd-current@FreeBSD.ORG Subject: Re: load spike strangeness X-Newsgroups: list.freebsd-stable In-Reply-To: <85820f$qbq$1@atlantis.rz.tu-clausthal.de> User-Agent: tin/1.4.1-19991201 ("Polish") (UNIX) (FreeBSD/3.4-19991219-STABLE (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG FreeBSD wrote in list.freebsd-stable: > Overclocking is *NEVER* recommended Neither is posting anonymously (without a realname). (Sorry -- Back to the topic.) I have to admit that I've seen the same symptoms, and I have no idea what's causing it. It happenes very irregularly (and rarely), but it clearly _does_ happen sometimes. It doesn't seem to be related to any particular hardware or FreeBSD ver- sion, I have seen it on both 3.x and 4.0-current boxes. On some machines it never happened at all (including some busy servers), at least not while I was logged in and watched it (it's possible that it happened without me noticing at all). It _seems_ to happen preferably when a long-time CPU hog has run (and terminated) recently, such as setiathome. The load goes up to 1.0 and stays there for some time (could be a few minutes, or an hour maybe even a few hours), then drops back to 0.0 for no apparent reason. During that period of load 1.0, there is no activity. CPU is 100% idle. There is no process that consumes any significant amounts of CPU time. The box feels fast and responds quickly to interactive work. vmstat looks perfectly normal (like an idle machine). I have come to the conclusion that it must be a subtle bug somewhere in the kernel's calculation of the load averages. I tried to track it down in the kernel sources, but without success. Since it didn't seem to have any ill effects, but just being a cosmetic problem, I didn't bother to investigate further. I have to admit that I wasn't even motivated to submit a PR. Yeah, shame on me. Oh by the way, I think it happened once even on an OpenBSD/ Alpha box (not sure though, it was a long time ago). Maybe it's a long-standing BSD bug, or just strange coincidence. Please excuse me for forwarding this to -current as well, but I think it's important enough, and -current is affected, too. Regards Oliver -- Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany (Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de) "In jedem Stück Kohle wartet ein Diamant auf seine Geburt" (Terry Pratchett) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message