On Tue, 24 Nov 2020 at 11:26, Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Tue 24-11-20 10:58:36, Aaron Tomlin wrote: > > Each memory-controlled cgroup is assigned a unique ID and the total > > number of memory cgroups is limited to MEM_CGROUP_ID_MAX. > > > > This patch provides the ability to determine the number of > > memory cgroups from the root memory cgroup, only. > > A value of 1 (i.e. self count) is returned if there are no children. > > For example, the number of memory cgroups can be established by > > reading the /sys/fs/cgroup/memory/memory.total_cnt file. > Hi Michal, > Could you add some explanation why is this information useful for > userspace? Who is going to use it and why a simple scripting on top of > cgroupfs is insufficient. Thank you for your feedback. Indeed, one can use a command/script to manually calculate this. Having said that, one that creates a significant number of memory-controlled cgroups may prefer a quick, simple and reliable method to generate the aforementioned data, for management purposes only. As such, I thought this patch might be particularly useful. Kind regards, -- Aaron Tomlin