From owner-freebsd-current@FreeBSD.ORG Sun Nov 30 06:38:56 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 790D116A4CE for ; Sun, 30 Nov 2003 06:38:56 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 31DF643FA3 for ; Sun, 30 Nov 2003 06:38:55 -0800 (PST) (envelope-from phk@phk.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.10/8.12.10) with ESMTP id hAUEcsgS026323; Sun, 30 Nov 2003 15:38:54 +0100 (CET) (envelope-from phk@phk.freebsd.dk) To: Colin Percival From: "Poul-Henning Kamp" In-Reply-To: Your message of "Sun, 30 Nov 2003 14:34:37 GMT." <5.0.2.1.1.20031130143248.020dc740@popserver.sfu.ca> Date: Sun, 30 Nov 2003 15:38:54 +0100 Message-ID: <26322.1070203134@critter.freebsd.dk> 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 14:38:56 -0000 In message <5.0.2.1.1.20031130143248.020dc740@popserver.sfu.ca>, Colin Percival writes: >At 15:30 30/11/2003 +0100, Poul-Henning Kamp wrote: >>In message <5.0.2.1.1.20031130140203.031e8d08@popserver.sfu.ca>, Colin >>Percival >> writes: >> > 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. > >I've seen UNIX systems have "typical" system/user splits from 1/9 to 9/1 >>it all depends on what you're doing. > > Sure, but buildworld is a fairly well-defined benchmark; I wouldn't >expect to see such a large difference when running exactly the same code on >different systems. The amount of system time depends on a lot of environmental factors. For instance on my amd64/SMP, the vnode pool is mis-sized, so the the namecache does not reflect what is actually already in RAM. The result is a fair bit of system time wasted instantiating vnodes from cached inode diskblocks. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.