> Howdy guys.
> 
> I noticed huge problems with system response time on 4.99.1.
> I upgraded my DOM0 kernel to 4.99.1 still running 3.99.21 on DOMU.
> Now, every time I ran something using my CPU, like compiling new kernel, 
> the DOMU become very irresponsive. Things started take long time from
> ping times rising to 100-200 ms between DOMU and DOM0 to time it took to 
> boot my DOMU.
> Things came back to normal when I didn't use my DOMO CPU.

it's normal with xen3 default scheduler setting.

> When I run 4.99.1 on both XEN0 and XENU the XENU was irresponsive
> no metter if CPU usage on the XEN0 was 0 or 100%.

i couldn't reproduce it.

> One other guy on #NetBSD on freenode noticed the same problem.
> In his case he was running 3.99.x on DOM0 and 4.9.1 on DOMU.

same as which of the above?

YAMAMOTO Takashi