On Thu, May 06, 2021 at 10:06:32PM -0400, Kenny Ho wrote:

Sorry for the late reply (I have been working on other stuff.)

On Fri, Feb 5, 2021 at 8:49 AM Daniel Vetter [off-list ref] wrote:

quoted

So I agree that on one side CU mask can be used for low-level quality
of service guarantees (like the CLOS cache stuff on intel cpus as an
example), and that's going to be rather hw specific no matter what.

But my understanding of AMD's plans here is that CU mask is the only
thing you'll have to partition gpu usage in a multi-tenant environment
- whether that's cloud or also whether that's containing apps to make
sure the compositor can still draw the desktop (except for fullscreen
ofc) doesn't really matter I think.

This is not correct.  Even in the original cgroup proposal, it
supports both mask and count as a way to define unit(s) of sub-device.
For AMD, we already have SRIOV that supports GPU partitioning in a
time-sliced-of-a-whole-GPU fashion.

Hm I missed that. I feel like time-sliced-of-a-whole gpu is the easier gpu
cgroups controler to get started, since it's much closer to other cgroups
that control bandwidth of some kind. Whether it's i/o bandwidth or compute
bandwidht is kinda a wash.

CU mask feels a lot more like an isolation/guaranteed forward progress
kind of thing, and I suspect that's always going to be a lot more gpu hw
specific than anything we can reasonably put into a general cgroups
controller.

Also for the time slice cgroups thing, can you pls give me pointers to
these old patches that had it, and how it's done? I very obviously missed
that part.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch