Re: [RFC PATCH v3 1/2] cgroup: cgroup.freeze.stat.local time accounting

[Tiffany Yang <ynaffit@google.com>]

Tejun Heo <tj@kernel.org> writes:

> Hello,

> Generally looks good to me. Some comments on cosmetics / interface.

> On Mon, Aug 04, 2025 at 08:29:41PM -0700, Tiffany Yang wrote:
> ...
>> +  cgroup.freeze.stat.local

> This was mentioned before and maybe I missed the following discussions but
> given that cgroup.freeze is a part of core cgroup, cgroup.stat.local is
> probably the right place. It's not great that cgroup.stat wouldn't be a
> superset of cgroup.stat.local but we can add the hierarchical counter  
> later
> if necessary.

Got it. I had ended up opting for the "freeze"-specific name because
there was already a cgroup_local_stat_show that seemed to imply that
cgroup.stat.local was reserved for controllers with a struct
cgroup_subsys. I will update v4 with something similar for core!


>> +	A read-only flat-keyed file which exists in non-root cgroups.
>> +	The following entry is defined:
>> +
>> +	  freeze_time_total

> How about just frozen_usec? "_usec" is what we used in cpu.stat for time
> stats.

Ack.


>> +		Cumulative time that this cgroup has spent between freezing and
>> +		thawing, regardless of whether by self or ancestor groups.
>> +		NB: (not) reaching "frozen" state is not accounted here.
>> +
>> +		Using the following ASCII representation of a cgroup's freezer
>> +		state, ::

> It's a bit odd to include credit in a doc file. Maybe move it to the
> description or add Co-developed-by: tag?


Will do! Thanks for looking over this :).

-- 
Tiffany Y. Yang