Taking for example this hierarchy from systemd-cgls:
└─user.slice
├─user-1000.slice
│ ├─user@1000.service
│ │ └─init.scope
│ │ ├─3262 /lib/systemd/systemd --user
│ │ └─3263 (sd-pam)
│ └─session-3.scope
│ ├─3260 sshd: user1 [priv]
│ ├─3362 sshd: user1@pts/1
│ ├─3363 -bash
│ └─3378 ssh-agent -s
└─user-0.slice
├─session-1.scope
│ ├─3151 sshd: root@pts/0
│ ├─3252 -bash
│ ├─3625 systemd-cgls
If I set a limit for user.slice, for example 5M of memory, the Memory line clearly report it:
systemctl status user.slice
● user.slice
Loaded: loaded (/etc/systemd/system/user.slice; static; vendor preset: enabled)
Active: active since Mon 2016-08-22 11:32:13 CEST; 52min ago
Tasks: 12
Memory: 3.1M (limit: 5.0M)
CPU: 1.275s
CGroup: /user.slice
...
The user-1000 slice have the limit applied, if I stress the system with this user I can see it. But the status don't report the limit in this child slice:
systemctl status user-1000.slice
● user-1000.slice - User Slice of user1
Loaded: loaded (/run/systemd/transient/user-1000.slice; transient; vendor preset: enabled)
Transient: yes
Active: active since Mon 2016-08-22 11:32:42 CEST; 1h 8min ago
Tasks: 6 (limit: 12288)
Memory: 856.0K
CPU: 521ms
Following the proc way I can see that the user-1000 process belong to the user slice:
# cat /proc/3260/cgroup
10:memory:/user.slice/user-1000.slice
...
And checking directly inside the /sys/:
root@server1:/sys/fs/cgroup/memory/user.slice# cat memory.limit_in_bytes
5242880
root@server1:/sys/fs/cgroup/memory/user.slice# cd user-1000.slice/
root@server1:/sys/fs/cgroup/memory/user.slice/user-1000.slice# cat memory.limit_in_bytes
9223372036854771712
How is possible to know if a child process/slice have a limit defined in a parent cgroup?
