[clug] finding source of high wait states

[Ben Nizette]

On Mon, 2009-09-21 at 16:06 +1000, jm wrote:
> I've got a machine which is suffering from high CPU wait states. The 
> load on the machine is sitting around 15 and it's spending about 60-90% 
> of time in the wait state. This is normally assoicated with I/O of some 
> form. I'm guessing disk. Is there someway to track down which program(s) 
> are causing this, which files are being accessed, is there any i/o 
> errors (checked logs including dmesg and don't see any), etc?

latencytop [1].  Note that a lot of the "patch your kernel" stuff on
their site is out of date; if you're running a recent kernel then afaick
it should "just work".  It's also available pre-packaged for a few
distros but I'd recommend rolling our own as it's under fairly active
development and the packages tend to be out of date.

	--Ben.

[1] http://www.latencytop.org/