Re: [PATCH] scheduler hints

Gerrit Huizenga
2002-06-06T01:20:41Z

In message <1023325903.912.390.camel@sinai>, > : Robert Love writes:
> On Wed, 2002-06-05 at 18:05, Gerrit Huizenga wrote:
>
> > Actually, process-to-process affinity, which was later generalized
> > as a process gang affinity.
>
> Oh OK, gang affinity - a bit different and not what we do now :)
>
> Interesting to look into, although not terribly useful I suspect weighed
> against its implementation...
>
> Robert Love

Our scheduler *was* a long set of conditionals. However, from the
stock BSD scheduler through the contorted thing that it became, we
saw something like 30-50% increases in some workloads. I think
the motivator was actually not Oracle originally but something like
SAP. Specific numbers are hard to extract now since we did so many
SMP & NUMA changes over the years, but I think I remember a slide
showing over 30% increase in SAP for this one additional feature.
I don't know that I ever saw specific Oracle or Oracle Apps numbers
for this although it was viewed as a "large" benefit, especially
in NUMA machines, but even on SMP machines.

gerrit