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Cgroups : Create Control Groups
2017/08/30 |
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Create Control Groups.
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| [1] | Confirm current valid subsystems on the System. |
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[root@dlp ~]# lssubsys cpuset cpu,cpuacct memory devices freezer net_cls,net_prio blkio perf_event hugetlb pids |
| [2] | For example, Create a Control Group under the CPU subsystem. |
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# show current settings for cpu subsystem [root@dlp ~]# cgget -g cpu /
/:
cpu.rt_period_us: 1000000
cpu.rt_runtime_us: 950000
cpu.stat: nr_periods 0
nr_throttled 0
throttled_time 0
cpu.cfs_period_us: 100000
cpu.cfs_quota_us: -1
cpu.shares: 1024
# create a Control group named [cpu_quota-70] [root@dlp ~]# cgcreate -g cpu:/cpu_quota-70
# confirm [root@dlp ~]# cgget -g cpu /cpu_quota-70
/cpu_quota-70:
cpu.rt_period_us: 1000000
cpu.rt_runtime_us: 0
cpu.stat: nr_periods 0
nr_throttled 0
throttled_time 0
cpu.cfs_period_us: 100000
cpu.cfs_quota_us: -1
cpu.shares: 1024
# change [cpu.cfs_quota_us]'s parameter to [70000μs] # possible to access CPU for [70000μs] time per [100000μs] which is the [cpu.cfs_period_us]'s parameter [root@dlp ~]# cgset -r cpu.cfs_quota_us=70000 cpu_quota-70 [root@dlp ~]# cgget -g cpu /cpu_quota-70
/cpu_quota-70:
cpu.rt_period_us: 1000000
cpu.rt_runtime_us: 0
cpu.stat: nr_periods 0
nr_throttled 0
throttled_time 0
cpu.cfs_period_us: 100000
cpu.cfs_quota_us: 70000
cpu.shares: 1024
# setting is created under the specified subsystem like follows [root@dlp ~]# ll /sys/fs/cgroup/cpu/cpu_quota-70 total 0 -rw-rw-r--. 1 root root 0 Aug 31 19:51 cgroup.clone_children --w--w----. 1 root root 0 Aug 31 19:51 cgroup.event_control -rw-rw-r--. 1 root root 0 Aug 31 19:51 cgroup.procs -r--r--r--. 1 root root 0 Aug 31 19:51 cpuacct.stat -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpuacct.usage -r--r--r--. 1 root root 0 Aug 31 19:51 cpuacct.usage_percpu -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpu.cfs_period_us -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpu.cfs_quota_us -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpu.rt_period_us -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpu.rt_runtime_us -rw-rw-r--. 1 root root 0 Aug 31 19:51 cpu.shares -r--r--r--. 1 root root 0 Aug 31 19:51 cpu.stat -rw-rw-r--. 1 root root 0 Aug 31 19:51 notify_on_release -rw-rw-r--. 1 root root 0 Aug 31 19:51 tasks |
| [3] | For adding specific process in the Control Group above, set like follows. |
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# run a job which places stress on CPU for a test [root@dlp ~]# yes > /dev/null & [1] 1116 # show processes on [top] command [root@dlp ~]# top -b -n 1 -p 1116 top - 13:33:47 up 2 min, 1 user, load average: 0.30, 0.08, 0.03 Tasks: 1 total, 1 running, 0 sleeping, 0 stopped, 0 zombie %Cpu(s): 7.4 us, 1.2 sy, 0.0 ni, 91.3 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem : 4046872 total, 3811756 free, 111808 used, 123308 buff/cache KiB Swap: 3145724 total, 3145724 free, 0 used. 3736592 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1116 root 20 0 107896 608 512 R 100.0 0.0 0:16.90 yes # show CPU usage per CPU cores (average of CPU#0 is now 100% by the test job above) [root@dlp ~]# mpstat -P ALL 1 1 | grep ^Average Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 49.75 0.00 0.50 0.00 0.00 0.00 0.00 0.00 0.00 49.75 Average: 0 100.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average: 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 # add the test proccess to [cpu_quota-70] group [root@dlp ~]# cgclassify -g cpu:cpu_quota-70 1116
# specified process is added in [tasks] of Control Group like follows [root@dlp ~]# cat /sys/fs/cgroup/cpu/cpu_quota-70/tasks 1116 # just turned to 70% of CPU average by Control Group like follows [root@dlp ~]# mpstat -P ALL 1 1 | grep ^Average Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 34.67 0.00 0.50 0.00 0.00 0.00 0.00 0.00 0.00 64.82 Average: 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: 1 70.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 30.00 |
| [4] | If you'd like to remove a Control Group, set like follows. |
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[root@dlp ~]#
cgdelete cpu:cpu_quota-70
# confirm setting [root@dlp ~]# lscgroup -g cpu:/cpu_quota-70 |
| [5] | The Control Groups that is added by [cgcreate] command is cleared when System restarts, so if you'd like to set it persistence, configure it in setting file like follows. |
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[root@dlp ~]#
vi /etc/cgconfig.d/cpu_quota-70.conf # create new setting file
group cpu_quota-70 {
cpu {
cpu.cfs_quota_us="70000";
}
}
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