On Wed, May 01, 2019 at 10:04:33AM -0400, Brian Welty wrote: > In containerized or virtualized environments, there is desire to have > controls in place for resources that can be consumed by users of a GPU > device. This RFC patch series proposes a framework for integrating > use of existing cgroup controllers into device drivers. > The i915 driver is updated in this series as our primary use case to > leverage this framework and to serve as an example for discussion. > > The patch series enables device drivers to use cgroups to control the > following resources within a GPU (or other accelerator device): > * control allocation of device memory (reuse of memcg) > and with future work, we could extend to: > * track and control share of GPU time (reuse of cpu/cpuacct) > * apply mask of allowed execution engines (reuse of cpusets) Please create a separate controller for your purposes. The memory controller is for traditional RAM. I don't see it having much in common with what you're trying to do, and it's barely reusing any of the memcg code. You can use the page_counter API directly. > Instead of introducing a new cgroup subsystem for GPU devices, a new > framework is proposed to allow devices to register with existing cgroup > controllers, which creates per-device cgroup_subsys_state within the > cgroup. This gives device drivers their own private cgroup controls > (such as memory limits or other parameters) to be applied to device > resources instead of host system resources. > Device drivers (GPU or other) are then able to reuse the existing cgroup > controls, instead of inventing similar ones. > > Per-device controls would be exposed in cgroup filesystem as: > mount/<cgroup_name>/<subsys_name>.devices/<dev_name>/<subsys_files> > such as (for example): > mount/<cgroup_name>/memory.devices/<dev_name>/memory.max > mount/<cgroup_name>/memory.devices/<dev_name>/memory.current > mount/<cgroup_name>/cpu.devices/<dev_name>/cpu.stat > mount/<cgroup_name>/cpu.devices/<dev_name>/cpu.weight Subdirectories for anything other than actual cgroups are a no-go. If you need a hierarchy, use dotted filenames: gpu.memory.max gpu.cycles.max etc. and look at Documentation/admin-guide/cgroup-v2.rst's 'Format' and 'Conventions', as well as how the io controller works, to see how multi-key / multi-device control files are implemented in cgroup2.
