On Thu, 15 Dec 2011, Avi Kivity wrote:

On 12/14/2011 07:58 PM, Eric B Munson wrote:

quoted

quoted

I don't think you should see a guest softlockup if the host is
overloaded.  Nor should you see it due to a long live migration pause,
or STOP/CONT.  You should see a guest softlockup if it is spinning due
to a guest bug, and not for any other reason.

I think we need a mix of the ioctl (for STOP/CONT and voluntary pauses,
like live migration or qemu stop/cont) and preempt notifiers (together
with a check for TASK_RUNNING/TASK_UNINTERRUPTIBLE, for scheduling or
swap delays)

Do you want the preemption notifier work in before you will consider merging
this set, or can that be a follow on?

Yes please.

-- 
error compiling committee.c: too many arguments to function

I am working on V7 to incorporate the __this_cpu_and suggestion, would you
consider that for inclusion and we can continue discussing the need for the
preemption notification work?  I think that having a guest complain when the
host is so loaded that the guest watchdog threads can't make any progress is
desirable behavior, it may be the only notification that an admin gets that a
particular host is over loaded.

Eric