"Brandon Metcalf" <bmetcalf@nortel.com> writes:
> We've been tuning the kernel (2.4 SMP flavor) and have improved
> performance quite a bit. I'm now wondering if turning off HT will
> improve performance even more. Based on the vmstat output below, is
> the context switching typical or too high?
Given that your CPU usage is hovering around 2%, it's highly unlikely
that you'll be able to measure any change at all by fiddling with HT.
What you need to be working on is disk I/O --- the "80% wait" number
is what should be getting your attention, not the CS number.
(FWIW, on the sort of hardware you're talking about, I wouldn't worry
about CS rates lower than maybe 10000/sec --- the hardware can sustain
well over 10x that.)
regards, tom lane