Hello,

On Mon, Aug 24, 2015 at 01:54:08PM -0700, Paul Turner wrote:

quoted

That alone doesn't require hierarchical resource distribution tho.
Setting nice levels reasonably is likely to alleviate most of the
problem.

Nice is not sufficient here.  There could be arbitrarily many threads
within the hypervisor that are not actually hosting guest CPU threads.
The only way to have this competition occur at a reasonably fixed
ratio is a sub-hierarchy.

I get that having hierarchy of threads would be nicer but am having a
bit of difficulty seeing why adjusting priorities of threads wouldn't
be sufficient.  It's not like threads of the same process competing
with each other is a new problem.  People have been dealing with it
for ages.  Hierarchical management can be a nice plus but we want the
problem and proposed solution to be justifiable.

Thanks.

-- 
tejun