dbench scalability testing
anton at linuxcare.com.au
Fri Mar 9 00:01:53 GMT 2001
> I work for the OSDL and we are attempting to script some dbench
> run-throughs to help us test the scalability of some of the samba/Linux
> kernel code.
> The problem is, using a single kernel image (2.2.18) on the same hardware
> without any other system activity I can't get reliable results.
At this point, testing on 2.4 would be better. Most of us are working there
and not on 2.2.
> I have taken precautions to exclude caching issues from the list of
> possible problems, but for some reason I still can't get the results to be
> I have posted the results at the following location, if anyone can offer
> some help, I would appreciate it. Right now, booting and running the
> benchmark gives different results than running the benchmark after 8 or so
> hours of uptime.
I have been able to get reliable results with recent 2.4 kernels. For
benchmarking purposes, increasing the async and sync flush points helps:
30 64 64 256 5000 30000 60 0 0
90 64 64 256 5000 30000 95 0 0
Netbench is such a bogus benchmark but we are stuck with it and we can
optimise for it nicely :)
> If you want more info on the OSDL, please see www.osdlab.org - we have 4 &
> 8 and (soon to be available) 16 processor boxes for use by the open source
Excellent, I've been doing samba/linux performance work but at this point
I only have a quad cpu machine. Can your network cards do zero copy? I
have a few samba patches including making samba use sendfile which could
help when you get around to doing netbench runs.
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