Re: 2.5.36-mm1 dbench 512 profiles

[Martin J. Bligh]

> AFAICT, with one bottleneck out of the way, a new one merely arises to
> take its place. Ugly. OTOH the qualitative difference is striking. The
> interactive responsiveness of the machine, even when entirely unloaded,
> is drastically improved, along with such nice things as init scripts
> and kernel compiles also markedly faster. I suspect this is just the
> wrong benchmark to show throughput benefits with.
> 
> Also notable is that the system time was significantly reduced though
> I didn't log it. Essentially a long period of 100% system time is
> entered after a certain point in the benchmark, during which there are
> few (around 60 or 70) context switches in a second, and the duration
> of this period was shortened.
> 
> The results here contradict my prior conclusions wrt. HZ 100 vs. 1000.

Hmmm ... I think you need the NUMA aware scheduler ;-) 
On the plus side, that does look like RCU pretty much obliterated the dcache
problems ....

M.