Re: [PATCH v7 11/15] sched/core: uclamp: Extend CPU's cgroup controller

From: Tejun Heo
Date: Thu Feb 14 2019 - 10:48:24 EST


On Fri, Feb 08, 2019 at 10:05:50AM +0000, Patrick Bellasi wrote:
> a) are available only for non-root nodes, both on default and legacy
> hierarchies, while system wide clamps are defined by a generic
> interface which does not depends on cgroups
> b) do not enforce any constraints and/or dependencies between the parent
> and its child nodes, thus relying:
> - on permission settings defined by the system management software,
> to define if subgroups can configure their clamp values
> - on the delegation model, to ensure that effective clamps are
> updated to consider both subgroup requests and parent group
> constraints

I'm not sure about this hierarchical behavior.

> c) have higher priority than task-specific clamps, defined via
> sched_setattr(), thus allowing to control and restrict task requests

and I have some other concerns about the interface, but let's discuss
them once the !cgroup portion is settled.