Subject: Re: Thread benchmarks
To: Thor Lancelot Simon <tls@rek.tjls.com>
From: Andrew Doran <ad@netbsd.org>
List: tech-kern
Date: 09/28/2007 20:39:49
On Fri, Sep 28, 2007 at 02:27:34PM -0400, Thor Lancelot Simon wrote:

> On Fri, Sep 28, 2007 at 06:50:16PM +0100, Andrew Doran wrote:
> > 
> > And NetBSD-current compared to other systems:
> > 
> >         http://www.netbsd.org/~ad/sysbench/netbsd-and-others.png
> 
> Something interesting's happening in the Linux line on the graph right
> at the right edge of the plotted region (20 threads).  Could you perhaps
> run NetBSD-current against Linux again with the maximum number of threads
> ramping up to 40, to see what the two curves look like as we head in
> that direction?

I have also tried 10-100 and 100-1000 client connections. I don't have the
numbers at hand, but Linux peaks around 550 tps somewhere around 100 client
connections. The numbers I was getting from Linux were quite erratic and I
had to throw out a few sets of results where the downward spikes were so bad
that the results were basically useless.

> Either we degrade a lot more gracefully than Linux under load, or there's
> an artifact in the Linux graph.  The current plot makes it impossible to
> tell which, though.

In the long run Linux will beat NetBSD. That said it the behaviour I saw on
this test cannot be called graceful!

Thanks,
Andrew