Path: utzoo!mnetor!uunet!husc6!mailrus!nrl-cmf!ames!elroy!cit-vax!mangler
From: mangler@cit-vax.Caltech.Edu (Don Speck)
Newsgroups: comp.unix.wizards
Subject: Re: Compressing unix disks
Message-ID: <6139@cit-vax.Caltech.Edu>
Date: 15 Apr 88 08:08:30 GMT
References: <1071@ndmath.UUCP> <2452@umd5.umd.edu> <305@marconi.SW.MCC.COM> <7582@ncoast.UUCP>
Organization: California Institute of Technology
Lines: 16
Summary: CPU usage of BSD & SysV filesystems

In article <7582@ncoast.UUCP>, allbery@ncoast.UUCP (Brandon Allbery) writes:
> you seem to need CPU to use the Berkeley FFS, and System V is popular on the
> little *nix boxes.

I've heard over and over that the Berkeley Fast Filesystem is considered a
CPU hog.  So I tried a trivial experiment, a program that does 512 writes
of 8K bytes each (enough to exceed the buffer cache) and the times were:

3B20S SysV.2,  1K fs blocksize	    32.6 real  0.0 user  11.4 sys
vax-750 4.3BSD 8K fs blocksize	     8.5 real  0.0 user   8.2 sys

BSD beat SysV in system time, even though SysV was running
on a CPU twice as fast and optimized for SysV!	So why does
everybody claim that the BSD filesystem is a CPU hog?

Don Speck   speck@vlsi.caltech.edu  {amdahl,ames!elroy}!cit-vax!speck