From owner-freebsd-current@FreeBSD.ORG Sun Nov 30 08:09:18 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3CB5D16A4CE for ; Sun, 30 Nov 2003 08:09:18 -0800 (PST) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 27AB843F85 for ; Sun, 30 Nov 2003 08:09:17 -0800 (PST) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (localhost [127.0.0.1]) by fledge.watson.org (8.12.9p2/8.12.9) with ESMTP id hAUG6cMg066639; Sun, 30 Nov 2003 11:06:38 -0500 (EST) (envelope-from robert@fledge.watson.org) Received: from localhost (robert@localhost)hAUG6cDL066636; Sun, 30 Nov 2003 11:06:38 -0500 (EST) (envelope-from robert@fledge.watson.org) Date: Sun, 30 Nov 2003 11:06:38 -0500 (EST) From: Robert Watson X-Sender: robert@fledge.watson.org To: Colin Percival In-Reply-To: <5.0.2.1.1.20031130140203.031e8d08@popserver.sfu.ca> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-current@freebsd.org Subject: Re: user:sys time ratio X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Nov 2003 16:09:18 -0000 On Sun, 30 Nov 2003, Colin Percival wrote: > I've got a system running 5.2-BETA from 27/11/03, with the > malloc_abort, malloc_junk, DEBUG=-g, DDB, INVARIANT*, and WITNESS* > debugging options changed (as was done in 5.1-RELEASE). > When running `make buildworld`, I see large amounts of sys time; eg, > 27 minutes user & 14 minutes sys for building 5.2, or 14 minutes user & > 10 minutes sys for building 4.9. I expected the ratio of user:sys to be > much larger than this, and mailing list traffic indicates that a 4:1 > ratio is typical. (FWIW, prior to changing the debugging options, the > user:sys time ratio was around 1:1.) > Can anyone suggest why the kernel seems to be behaving so sluggishly? > > The system hardware is P4 2.8Ghz, 865G, 2GB DDR, IDE drives; there is > very little disk activity, so I'm sure that isn't the issue; and > disabling HTT results in about a 2% improvement in both user and sys > times. It sounds like you have multiple logical cores -- have you tried building a kernel without SMP support to see what happens? Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert@fledge.watson.org Senior Research Scientist, McAfee Research