Re: Poor NFS server performance in 6.0 with SMP and mpsafenet=1

From: Gavin Atkinson <gavin.atkinson_at_ury.york.ac.uk>
Date: Wed, 02 Nov 2005 15:37:29 +0000
On Wed, 2005-11-02 at 16:23 +0100, Bernd Walter wrote:
> On Wed, Nov 02, 2005 at 02:58:36PM +0000, Gavin Atkinson wrote:
> > I'm seeing incredibly poor performance when serving files from an SMP
> > FreeBSD 6.0RC1 server to a Solaris 10 client.  I've done some
> > experimenting and have discovered that either removing SMP from the
> > kernel, or setting debug.mpsafenet=0 in loader.conf massively improves
> > the speed.  Switching preemption off seems to also help.
> > 
> > No SMP, mpsafenet=1			 59.4
> > No SMP, mpsafenet=0			 49.4
> > No SMP, mpsafenet=1, no PREEMPTION	 53.1
> > No SMP, mpsafenet=0, no PREEMPTION	 51.9
> >    SMP, mpsafenet=1			351.7
> >    SMP, mpsafenet=0			 74.5
> >    SMP, mpsafenet=1, no PREEMPTION	264.9
> >    SMP, mpsafenet=0, no PREEMPTION	 53.7
> 
> Which scheduler?

BSD.  As I say, I'm running 6.0-RC1 with the standard GENERIC kernel,
apart from the options I have listed as being changed above.  Polling is
therefore also not enabled.

When I get home, I'll have a play with both ULE and POLLING to see what
difference they make, however ideally I'd like to not use polling in
production if possible.

Gavin
Received on Wed Nov 02 2005 - 14:37:39 UTC

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