Subject: more praise for UBC (and UVM)!
To: NetBSD-current Discussion List <current-users@NetBSD.ORG>
From: Greg A. Woods <>
List: current-users
Date: 04/16/2001 16:27:05
I'd like to take this opportunity to again praise the unified buffer
cache (and UVM) again (and to correct my previous post on this subject
which should of course also have referred to UBC).

It's been many years now since I've used a computer which made such
effective use of RAM as NetBSD-current now does.  Even SunOS-4.1 had its
limitations when compared against even AT&T System V Release 3.2, never
mind Release 4.0 (which of course compares more favourably with SunOS-5,
aka Solaris).

A perfect example of the improvment is in how well UBC assists multiple
runs of distrib/sets/checkflist.  Even on a relatively busy machine, but
one with lots of RAM, a second run of checkflist (even tens of seconds
later) literally flies by at incredible speed with almost no additional
disk I/O necessary!  I haven't been able to do that kind of thing on any
of my own computers since I was running SysVr3.2 on my 3B2!

Using the stock 1.5T (2001/03/24) kernel I don't even have any serious
complaints about interactive sluggishness (though the only large
applications I run on that machine are Emacs and Mozilla as X11 clients,
and both are sometimes sluggish and cause paging at even the best of
times!).  I've had no real problems editing while kernels build, for
example.  I must say that I am accustomed to using slower systems, but

							Greg A. Woods

+1 416 218-0098      VE3TCP      <>     <>
Planix, Inc. <>;   Secrets of the Weird <>