Re: Niced cron jobs

[Jeff Licquia <jeff@luci.org>]

On Sun, Jun 27, 1999 at 09:06:49PM -0400, Andrew Pimlott wrote:
> 
> Agreed.  Because nobody else had, I ran a few numbers on an otherwise
> unloaded system.  I compiled a kernel while running the slocate cron job
> (creates an index of the filesystem) at the default priority, and at
> niceness 10.  The compile finished about 8% sooner with the nice slocate.
> Interactive performance was fine in both cases.  If most cron jobs are
> disk-intensive like slocate's, it's not at all clear that nice buys much for
> joe user.
> 
> This is of course not a conclusive test.  It was run on a fast machine and
> the CPU was never maxed out.  But does anyone have more convincing evidence
> or arguments?

I own a low-end Pentium laptop with slink on it, a P90 with 16MB of
RAM.  Because I am a masochist, I ran KDE as my default desktop for a
while.  If that doesn't qualify as a heavily-loaded machine, I don't
know what does. :-)

I also have anacron on it.  Almost every time I would power it up, the 
system would start thrashing like crazy several minutes, and
interactive performance would drop through the floor.

As a test, I niced the run-parts entries in cron at 10.  After this,
it would still thrash a bit, but interactive performance was
definitely improved.

I don't have any hard numbers to justify this, so I don't know if it
qualifies as "more convincing".