Re: [PATCH v3 1/2] cgroup: Show # of subsystem CSSes in cgroup.stat

Waiman Long
2024-07-11T17:39:50Z

On 7/11/24 13:18, Tejun Heo wrote:
> Hello,
>
> On Thu, Jul 11, 2024 at 10:05:22AM -0400, Waiman Long wrote:
>> Given the fact that for_each_css() iteration is filtering out csses that are
>> absent, the dying counts follow the same logic of skipping it if there is no
>> dying css. That also makes it easier to identify cgroups with dying
>> descendant csses as we don't need filter out entries with a 0 dying count.
>> It also makes the output less verbose and let user focus more on what are
>> significant.
>>
>> I do understand that it makes it inconsistent with the ways nr_descendants
>> and nr_dying_descendants are being handled as entries with 0 count are also
>> displayed. I can update the patch to display those entries with 0 dying
>> subsys count if other people also think that is the better way forward.
> I think it'd be better to have all the keys. There are some dynamic keys in
> stat files but those are mostly for things which can come and go (e.g. block
> and misc devices), so yeah, I think it'd be better to show all the keys even
> when they're zero.
Currently, I use the for_each_css() macro for iteration. If you mean
displaying all the possible cgroup subsystems even if they are not
enabled for the current cgroup, I will have to manually do the iteration.
>
> Also, I personally would much prefer if the same prefixes are collected
> together - ie. totals first and then dying. It's just a lot easier on the
> eyes that way.
>
> nr_subsys_cpu
> nr_subsys_memory
> nr_subsys_io
> ...
> nr_dying_subsys_cpu
> nr_dying_subsys_memory
> nr_dying_subsys_io
> ...

That is fine. I can group entries with the same prefix together.

Cheers,
Longman