On Fri, May 13, 2022 at 9:13 AM Tejun Heo <tj@xxxxxxxxxx> wrote: > > Hello, > > On Thu, May 12, 2022 at 08:43:52PM -0700, T.J. Mercier wrote: > > > I'm actually happy I've asked this question, wasn't silly after all. I think the > > > problem here is a naming issue. What you really are monitor is "video memory", > > > which consist of a memory segment allocated to store data used to render images > > > (its not always images of course, GPU an VPU have specialized buffers for their > > > purpose). > > > > > > Whether this should be split between what is used specifically by the GPU > > > drivers, the display drivers, the VPU (CODEC and pre/post-processor) or camera > > > drivers is something that should be discussed. But in the current approach, you > > > really meant Video memory as a superset of the above. Personally, I think > > > generically (to de-Andronized your work), en-globing all video memory is > > > sufficient. What I fail to understand is how you will manage to distinguished > > > DMABuf Heap allocation (which are used outside of Android btw), from Video > > > allocation or other type of usage. I'm sure non-video usage will exist in the > > > future (think of machine learning, compute, other high bandwidth streaming > > > thingy ...) > > > > > Ok thank you for pointing out the naming issue. The naming is a > > consequence of the initial use case, but I guess it's too specific. > > What I want out of this change is that android can track dmabufs that > > come out of heaps, and drm can track gpu memory. But other drivers > > could track different resources under different names. Imagine this > > were called a buffer cgroup controller instead of a GPU cgroup > > controller. Then the use component ("video memory") isn't tied up with > > the name of the controller, but it's up to the name of the bucket the > > resource is tracked under. I think this meets the needs of the two use > > cases I'm aware of now, while leaving the door open to other future > > needs. Really the controller is just enabling abstract named buckets > > for tracking and eventually limiting a type of resource. > > So, there hasn't been whole lot of discussion w/ other GPU folks and what > comes up still seems to indicate that we're still long way away from having > a meaningful gpu controller. > Yes, and I would still be happy to collaborate. > For your use case, would it make sense to just > add dmabuf as a key to the misc controller? > Thanks for your suggestion. This almost works. "dmabuf" as a key could work, but I'd actually like to account for each heap. Since heaps can be dynamically added, I can't accommodate every potential heap name by hardcoding registrations in the misc controller. > I'm not sure it makes sense to > push "gpu controller" forward if there's no conceptual consensus around what > resources are. > > Thanks. > > -- > tejun