> check vzctl sources. it calls other OVZ-specific syscalls by 
> their numbers, like sys_setluid, sys_setublimit etc.
> 
> For creating fairsched node you'll need to call 
> fairsched_mknod first, then move the process to this node 
> using fairsched_mvpr

OK, I wrote a small (perl) script to test those syscalls, and everything
work as expected, for example:

..
fairsched_mknod (0, 500, 400);
fairsched_vcpus (400, 1);
set_cpulimit (400, 25);
fairsched_mvpr ($$, 400);
fork_and_do_something(); # runs with 25% cpu
wait
fairsched_rmnod (400);
..

work perfectly.

But when I call fairsched_rmnod(400) from another process while there is
still a process running inside 400 the system freezes. I get a kernel
panic somewhere inside move_task_off_dead_cpu.

any idea how to fix that?

- Dietmar