cgroup之cpu关键参数

cpu.cfs_period_us

specifies a period of time in microseconds (µs, represented here as "us") for how regularly a cgroup's access to CPU resources should be reallocated. If tasks in a cgroup should be able to access a single CPU for 0.2 seconds out of every 1 second, set cpu.cfs_quota_us to 200000 and cpu.cfs_period_us to 1000000. The upper limit of the cpu.cfs_quota_us parameter is 1 second and the lower limit is 1000 microseconds.

cpu.cfs_quota_us

specifies the total amount of time in microseconds (µs, represented here as "us") for which all tasks in a cgroup can run during one period (as defined by cpu.cfs_period_us). As soon as tasks in a cgroup use up all the time specified by the quota, they are throttled for the remainder of the time specified by the period and not allowed to run until the next period. If tasks in a cgroup should be able to access a single CPU for 0.2 seconds out of every 1 second, set cpu.cfs_quota_us to 200000 and cpu.cfs_period_us to 1000000. Note that the quota and period parameters operate on a CPU basis. To allow a process to fully utilize two CPUs, for example, set cpu.cfs_quota_us to 200000 and cpu.cfs_period_us to 100000.

Setting the value in cpu.cfs_quota_us to -1 indicates that the cgroup does not adhere to any CPU time restrictions. This is also the default value for every cgroup (except the root cgroup).

 

SETTING PARAMETERS

cpu_and_mem]# cgset -r cpuset.cpus=0-1 group1

The values that you can set with cgset might depend on values set higher in a particular hierarchy. For example, if group1 is limited to use only CPU 0 on a system, you cannot set group1/subgroup1 to use CPUs 0 and 1, or to use only CPU 1.

cgcreate -g cpu,net_cls:/test-subgroup

 The cgcreate command creates two groups named test-subgroup, one in the cpu_and_mem hierarchy and one in the net hierarchy. The test-subgroup group in the cpu_and_mem hierarchy is controlled by the memory subsystem, even though it was not specified in the cgcreate command.

 

The Cgroup Model

Cgroups are similar to processes in that:

• they are hierarchical, and
• child cgroups inherit certain attributes from their parent cgroup.

Multiple separate hierarchies of cgroups are necessary because each hierarchy is attached to one or more subsystems. A subsystem[2] represents a single resource, such as CPU time or memory. Red Hat Enterprise Linux 6 provides ten cgroup subsystems, listed below by name and function.

 

Per-group CPU and memory resource management 

In the /etc/cgconfig.conf file, configure the following subsystems to be mounted and cgroups to be created:

mount {
    cpu     = /cgroup/cpu_and_mem;
    cpuacct = /cgroup/cpu_and_mem;
    memory  = /cgroup/cpu_and_mem;
}

group finance {
        cpu {
                cpu.shares="250";
        }
        cpuacct {
                cpuacct.usage="0";
        }
        memory {
                memory.limit_in_bytes="2G";
                memory.memsw.limit_in_bytes="3G";
        }
}

group sales {
        cpu {
                cpu.shares="250";
        }
        cpuacct {
                cpuacct.usage="0";
        }
        memory {
                memory.limit_in_bytes="4G";
                memory.memsw.limit_in_bytes="6G";
        }
}

group engineering {
        cpu {
                cpu.shares="500";
        }
        cpuacct {
                cpuacct.usage="0";
        }
        memory {
                memory.limit_in_bytes="8G";
                memory.memsw.limit_in_bytes="16G";
        }
}

参考：

https://blog.csdn.net/zdy0_2004/article/details/54343384        --numa 架构

https://www.cnblogs.com/cenalulu/p/4358802.html   --  -numa 架构介绍

Relationships_Between_Subsystems_Hierarchies_Control_Groups_and_Tasks      --redhat 中文

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html-single/resource_management_guide/index#sect-cfs  --rhel6

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/resource_management_guide/index