Re: Interactivity issue in 2.6.25-rc3

[Ingo Molnar <mingo@elte.hu>]

* Ray Lee <ray-lk@madrabbit.org> wrote:

> But it's good to keep in mind that the scheduler can't do anything 
> about slowdowns due to tasks being swapped out or waiting on reads 
> from the disk. I mention this as shortly after CFS got into mainline, 
> something changed in the VM that seems to make my system spend a lot 
> more time in IO wait, causing the system to be much less responsive 
> than it used to be.
> 
> Unfortunately it seems to be dependent upon the history of what tasks 
> I've run and their memory usage, so it's been hard to come up with a 
> reproducible test case (well that and a complete lack of time). All I 
> can say is that I've seen what you've reported as well, though it had 
> nothing to do with using any 3d applications, just a browser, editor, 
> gcc, etc.

what does latencytop say about those delays, what causes them? It should 
be able to capture all sorts of latency sources in the system.

	Ingo