Re: [PATCH v2 00/11] new cgroup controller for gpu/drm subsystem

Tejun Heo
2020-04-13T21:53:30Z

Hello,

On Mon, Apr 13, 2020 at 05:40:32PM -0400, Kenny Ho wrote:
> By lack of consense, do you mean Intel's assertion that a standard is
> not a standard until Intel implements it? (That was in the context of
> OpenCL language standard with the concept of SubDevice.) I thought
> the discussion so far has established that the concept of a compute
> unit, while named differently (AMD's CUs, ARM's SCs, Intel's EUs,
> Nvidia's SMs, Qualcomm's SPs), is cross vendor. While an AMD CU is
> not the same as an Intel EU or Nvidia SM, the same can be said for CPU
> cores. If cpuset is acceptable for a diversity of CPU core designs
> and arrangements, I don't understand why an interface derived from GPU
> SubDevice is considered premature.

CPUs are a lot more uniform across vendors than GPUs and have way higher user
observability and awareness. And, even then, it's something which has limited
usefulness because the configuration is inherently more complex involving
topology details and the end result is not work-conserving.

cpuset is there partly due to historical reasons and its features can often be
trivially replicated with some scripting around taskset. If that's all you're
trying to add, I don't see why it needs to be in cgroup at all. Just implement
a tool similar to taskset and build sufficient tooling around it. Given how
hardware specific it can become, that is likely the better direction anyway.

Thanks.

--
tejun