From owner-freebsd-stable Thu Sep 7 13:55: 7 2000 Delivered-To: freebsd-stable@freebsd.org Received: from gaia.nimnet.asn.au (nimbin.lnk.telstra.net [139.130.45.143]) by hub.freebsd.org (Postfix) with ESMTP id F414C37B423 for ; Thu, 7 Sep 2000 13:55:03 -0700 (PDT) Received: from localhost (smithi@localhost) by gaia.nimnet.asn.au (8.8.8/8.8.8R1.0) with SMTP id GAA22268; Fri, 8 Sep 2000 06:54:53 +1000 (EST) (envelope-from smithi@nimnet.asn.au) Date: Fri, 8 Sep 2000 06:54:52 +1000 (EST) From: Ian Smith To: Vivek Khera Cc: stable@FreeBSD.ORG Subject: Re: Odd Load average problem In-Reply-To: <14775.65131.298732.839601@onceler.kciLink.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 7 Sep 2000, Vivek Khera wrote: > >>>>> "IS" == Ian Smith writes: > > IS> For what it's worth, I've noticed this occasionally over a couple of > IS> years on a 2.2.6 box; same, seems like 1.00 has been added to the load > IS> average, lasts for hours, goes away. Thought it'd be fixed ages ago :) > > There was a big discussion about this on the bsdi-users mailing list a > year or so ago. The gist of the problem was that on x86 architecture, > you don't have enough timers to measure the system without affecting > the system. Something about needing to make the resolution of the > measuring timer be relatively prime to the scheduling timer. Thus, it > is possible for the two logical timers to get in sync and artifically > increase the load. Usually running some CPU intensive job breaks the > synchronization. Guess that makes some sort of sense. Oddly maybe, I most often noticed this after running top just after an /etc/daily /etc/security run, one of the few times of day that the l.a. ever gets past 1 around here .. > This is from memory, so may be slightly inaccurate, and may not apply > to FreeBSD, though I suspect it does considering the issue was with > the hardware capabilities. A mystery it remains. Not one I've been too stressed about, but still. Thanks, Ian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message