Re: [RFC 00/60] Coscheduling for Linux

From: Subhra Mazumdar
Date: Thu Sep 27 2018 - 14:13:26 EST




On 09/24/2018 08:43 AM, Jan H. SchÃnherr wrote:
On 09/19/2018 11:53 PM, Subhra Mazumdar wrote:
Can we have a more generic interface, like specifying a set of task ids
to be co-scheduled with a particular level rather than tying this with
cgroups? KVMs may not always run with cgroups and there might be other
use cases where we might want co-scheduling that doesn't relate to
cgroups.
Currently: no.

At this point the implementation is tightly coupled to the cpu cgroup
controller. This *might* change, if the task group optimizations mentioned
in other parts of this e-mail thread are done, as I think, that it would
decouple the various mechanisms.

That said, what if you were able to disable the "group-based fairness"
aspect of the cpu cgroup controller? Then you would be able to control
just the coscheduling aspects on their own. Would that satisfy the use
case you have in mind?

Regards
Jan
Yes that will suffice the use case. We wish to experiment at some point
with co-scheduling of certain workers threads in DB parallel query and see
if there is any benefit

Thanks,
Subhra