3.2.3. Example Usage

Example 3.2. Limiting CPU access

The following examples assume you have an existing hierarchy of cgroups configured and the cpu subsystem mounted on your system:

To allow one cgroup to use 25% of a single CPU and a different cgroup to use 75% of that same CPU, use the following commands:

echo 250 > /cgroup/cpu/blue/cpu.shares
echo 750 > /cgroup/cpu/red/cpu.shares

~]# echo 250 > /cgroup/cpu/blue/cpu.shares
~]# echo 750 > /cgroup/cpu/red/cpu.shares

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To limit a cgroup to fully utilize a single CPU, use the following commands:

echo 10000 > /cgroup/cpu/red/cpu.cfs_quota_us
echo 10000 > /cgroup/cpu/red/cpu.cfs_period_us

~]# echo 10000 > /cgroup/cpu/red/cpu.cfs_quota_us
~]# echo 10000 > /cgroup/cpu/red/cpu.cfs_period_us

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To limit a cgroup to utilize 10% of a single CPU, use the following commands:

echo 10000 > /cgroup/cpu/red/cpu.cfs_quota_us
echo 100000 > /cgroup/cpu/red/cpu.cfs_period_us

~]# echo 10000 > /cgroup/cpu/red/cpu.cfs_quota_us
~]# echo 100000 > /cgroup/cpu/red/cpu.cfs_period_us

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On a multi-core system, to allow a cgroup to fully utilize two CPU cores, use the following commands:

echo 200000 > /cgroup/cpu/red/cpu.cfs_quota_us
echo 100000 > /cgroup/cpu/red/cpu.cfs_period_us

~]# echo 200000 > /cgroup/cpu/red/cpu.cfs_quota_us
~]# echo 100000 > /cgroup/cpu/red/cpu.cfs_period_us

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