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

From: Waiman Long
Date: Thu Jul 11 2024 - 15:30:10 EST



On 7/11/24 15:21, Tejun Heo wrote:
Hello,

On Thu, Jul 11, 2024 at 03:13:12PM -0400, Waiman Long wrote:
That will means cgroup subsystems that are seldomly used like rdma, misc or
even hugetlb will always be shown in all the cgroup.stat output. I actually
Hmm... yeah, that does increase the amount of output, but I don't know. The
trade-off is between consistency and brevity and I think I'd go for
consistency here.

prefer just showing those that are enabled. As for dying memory cgroups,
they will only be shown in its online ancestors. We currently don't know how
So, one peculiarity with memory is that when you enable io, it gets
implicitly enabled together and we likely wanna show that.

If memory is implicitly enabled, it is treated as enabled as the corresponding cgroup->subsys[] entry should be set. I currently don't filter out those in the cgrp_dfl_implicit_ss_mask. So perf_event, which is implicitly enabled, is shown in all the cgroup.stat.

If you still want to display all even if some of them are not enabled, I can certainly do that.

Cheers,
Longman