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

[Tiffany Yang <ynaffit@google.com>]

Hello!

> ...
> Glad that worked out, but I'm curious what are the involved time scales.
> Let's say you get things off by some tens of msecs, or maybe even  
> hundreds,
> does that matter for your purpose?


Our wotchdog timers are on the order of a few seconds. Tens of msecs
would be acceptable, but I think variances of hundreds of msecs would be
large enough to cause issues. I mainly wanted to include the rough
numbers in case anybody was curious about the actual magnitude of the
offsets (if they wanted this accounting for a different use case, for
example).


> While it's not my call, I'm not necessarily against. However, as you noted
> in another reply, the challenge is that there are multiple states and it's
> not clear what combinations would be useful for whom. When/if we encounter
> more real world use cases tha twould require these numbers, they may shed
> light on what the right combination / interface is. IOW, I'm not sure this
> is a case where adding something preemptively is a good idea.

Ack. The per-cgroup accounting gets us most of the way there, so I'll be
sending out that updated version shortly! I agree that another relevant
use case would be immensely helpful for figuring out a way to describe
the broader problem we are trying to solve and what shape a solution
should take.

Thank you for your feedback and for helping me to arrive at (what I hope
is) a reasonable approach.

-- 
Tiffany Y. Yang