Re: 2.6.4-mm2

[Mary Edie Meredith <maryedie@osdl.org>]

The 2.6.5-rc2-mm5 kernel has vastly improved the 
performance issue with dbt3-pgsql throughput numbers
(bigger is better):

Runid...Metric.PLM..Kernel........diff%
290357  141.84 2788 2.6.5-rc2.....  base 
290576   91.18 2814 2.6.5-rc2-mm2 -35.72
290856   60.02 2842 2.6.5-rc2-mm4 -57.68
290953  134.10 2849 2.6.5-rc2-mm5  -5.46 <-------

Thanks to Nick and Ingo. 

On Tue, 2004-03-23 at 16:07, Mary Edie Meredith wrote:
> On Tue, 2004-03-23 at 11:32, Andrew Morton wrote:
> > Mary Edie Meredith <maryedie@osdl.org> wrote:
> > >
> > > > 36% regression due to the CPU scheduler changes?  ow.
> > >  > 
> > >  > And that machine is a PIII, so presumably the setting of CONFIG_SCHED_SMT
> > >  > makes no difference.
> > >  > 
> > >  > >From a quick look at the material you have there it appears that this
> > >  > workload also is very I/O bound.  It's a little surprising that the CPU
> > >  > scheduler could make so much difference.
> > >  I'm not sure why you think this is IO bound. For 
> > >  the throughput phase of the test (from which the 
> > >  metric above is taken) there is very little physical 
> > >  IO except at the start when the updates occur.  They
> > >  finish in a few minutes, after which there is very
> > >  little.
> > > 
> > >  http://khack.osdl.org/stp/290304/results/plot/thuput.vmstat_io.png
> > >  http://khack.osdl.org/stp/290304/results/plot/thuput.vmstat.txt
> > 
> > There seems to be a large amount of idle time in the profiles and in the
> > vmstat trace.
> Yes.  There is considerably more idle time in the bad run:
> Good one:
> http://khack.osdl.org/stp/290298/results/plot/thuput.sar_cpu_all.png
> Bad one:
> http://khack.osdl.org/stp/290304/results/plot/thuput.sar_cpu_all.png
> 
> I am concerned with the drop in CPU utilization relative to
> the other run.     
-- 
Mary Edie Meredith 
maryedie@osdl.org
503-626-2455 x42
Open Source Development Labs