Re: 2.6.0test9 + 2 * P IV Xeon 2.4GHz with HT + SATA + RAID1 = scheduler problems

[Nick Piggin <piggin@cyberone.com.au>]

Catalin BOIE wrote:

>Hi!
>
>I want to tell you that 2.6.0-test gets better and better. It works very
>very well on several systems. Thank you very much, guys.
>
>I have an server (like in the subject). The problem is that the scheduler
>seems to behave weird. Sometimes a program just do nothing. There is no
>disk activity, interrupts are a little over 1000, no disk requests,
>context switches are ~40. The system is idle but it has work to do!
>Can I provide more info?
>
>I tried to put elevator=deadline and things seems worse.
>
>If I'm not mistaken, the processes are in D state. Bt I'm not sure, I must
>check again and right now I can't.
>

Hi,
Please capture a Ctrl + Scroll Lock dump when you get processes stuck in
D state.

>
>Also I suspect that scheduler doesn't pay special attention to virtual
>(HT) processors. Is this true?
>

This is correct. Are you seeing any problems with HT? I think Linus
was hoping the NUMA / SMP scheduler could be generalised a bit more
so that HT would just fall into place. This might not happen before
2.7, so the shared runqueue approach might be the next best thing
(I like it).