From owner-freebsd-hackers Thu Jun 24 12:37:49 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from dingo.cdrom.com (dingo.cdrom.com [204.216.28.145]) by hub.freebsd.org (Postfix) with ESMTP id C11AF1543D for ; Thu, 24 Jun 1999 12:37:47 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost.cdrom.com [127.0.0.1]) by dingo.cdrom.com (8.9.3/8.8.8) with ESMTP id MAA01020; Thu, 24 Jun 1999 12:34:06 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Message-Id: <199906241934.MAA01020@dingo.cdrom.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Dan Moschuk Cc: hackers@freebsd.org Subject: Re: Beating system usage down In-reply-to: Your message of "Thu, 24 Jun 1999 12:18:16 EDT." <19990624121816.A17448@trinsec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 24 Jun 1999 12:34:06 -0700 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Just for those that have been following the benchmarking thread, this is exactly the same symptom set that FreeBSD demonstrates when loaded by WebBench. The gotcha here is, again, the giant kernel lock. > Greetings, > > A machine that I hold very close under my wing has been very contently > chugging along for the last few months with practically no idle processor. > However, I noticed that the CPUs are spinning a lot of cycles in the > system area. > > CPU states: 5.5% user, 0.0% nice, 88.9% system, 4.0% interrupt, 1.6% idle > > First, some background. > > The machine is a Dual P2-450 with 1GB of RAM. It runs apache, and currently > handles 90 hits a second, with each of those hits spawning various CGIs > (one per hit) that completes in under a second. > > My first theory was that the kernel was uselessly spinning in various record > locks via fcntl(). However, as a test I removed all file locking from the > various CGIs and noticed no change in the system usage. My second theory > was the overhead with the SMP code. So, I removed it from the kernel and > ran a single CPU box for a few minutes. The system usage went down to > around 60%, but the system was noticeably slower. > > Any ideas? > > > Regards, > > Dan > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > -- \\ The mind's the standard \\ Mike Smith \\ of the man. \\ msmith@freebsd.org \\ -- Joseph Merrick \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message