Re: [RFC PATCH v2] cgroup: Track time in cgroup v2 freezer

[Michal Koutný]

On Thu, Jul 17, 2025 at 07:05:14AM -1000, Tejun Heo <tj@xxxxxxxxxx> wrote:
> I wonder what hierarchical summing would look like for this.

So do I.
Thus I meant to expose this only in a *.local file not the hierarchical
one.

But I realize it should [1] match cpu.stat[.local]:thottled_usec
since they're similar quantities in principle.
- cpu.stat:thottled_usec
  - sums the time the cgroup's quota was in effect
  - not hierarchical (:-/)
- cpu.stat.local:thottled_usec
  - not hierarchical
  - sums the time cgroup's or ancestor's quota was in effect
    -> IIUC this is what's the motivation of the original patch

HTH,
Michal

[1] I'd find it more logical if
cpu.stat:thottled_usec were cpu.stat.local:thottling_usec and
cpu.stat.local:thottled_usec were cpu.stat.local:throttled_usec.
Only to illustrate my understanding of hierarchy in cpu.stat, it doesn't
matter since it's what it is now.

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