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