Re: voluntary-preempt I0: sluggish feel

Ingo Molnar
2004-07-22T18:12:43Z

* Ingo Molnar <mingo@elte.hu> wrote:

> > Oh, sorry for the noise. It was the NVIDIA driver. The open one works
> > much better with the I0 patch.
>
> i can reproduce this and i dont have the NVIDIA driver. When logging
> in over the network then shell output is chunky with a setting of 2
> (softirq redirection), shell output is smooth with a value of 1.

found the reason: ksoftirqd runs at priority 19 by default and this
causes batching and some softirq starvation. Does the sluggishness go
away if you do 'renice -10 2' [where '2' is the PID of ksoftirqd]?

Ingo