On Fri, 2 Jul 2021 09:58:06 -0400 Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx> wrote: > > > My Vulkan knowledge is limited so I'm not sure whether this is the right > > > approach or not. In particular is it correct that an application can > > > create a high priority queue which could affect other (normal priority) > > > applications? > > > > That's what msm does (with no extra CAPS check AFAICT), and the > > freedreno driver can already create high priority queues if > > PIPE_CONTEXT_HIGH_PRIORITY is passed. Not saying that's okay to allow > > userspace to tweak the priority, but if that's a problem, other drivers > > are in trouble too ;-). > > Speaking of, how will PIPE_CONTEXT_HIGH_PRIORITY be implemented with the > new ioctl()? I envisioned something much simpler (for the old ioctl), > just adding a "high priority?" flag to the submit and internally > creating the two queues of normal/high priority for drm_sched to work > out. Is this juggling now moved to userspace? That's what freedreno does. I guess we could create 2 default queues (one normal and one high prio) and extend the old submit ioctl() to do what you suggest if you see a good reason to not switch to the new ioctl() directly. I mean, we'll have to keep support for both anyway, but switching to the new ioctl()) shouldn't be that hard (I can prepare a MR transitioning the gallium driver to BATCH_SUBMIT if you want).
