Subject: Re: MP Perfomance
To: None <>
From: Havard Eidnes <>
List: tech-smp
Date: 03/19/2004 10:24:18
> after building successfully an MP Kernel, I wonder why the
> performance does not increase equally.

You need to put load both processors.  Single-threaded programs
will only utilize one processor.

> Services like FTP runs slower compared to an UP Kernel on the same
> machine.

Not by much, I hope?

> Also compiling is not really faster. All I can detect is, that the
> avg load is the half since it shares on 2 processors.

You can use "-j 2" (or a slightly higher number) as make argument or
as an argument to, and make will try to start two
concurrent compiles, utilizing both processors.

> How can I detect, that 2 processors are running well? =

You can see which process runs on which CPU with "top".

> Where is the advantage of running multi?

For CPU-bound jobs, you have twice the capacity available.  For
kernel- and I/O-dominated jobs, the advantage is less, since NetBSD
still only allows one CPU to be active running kernel code.


- H=E5vard