System.CGroup.V1.CPU

Types and operations for the CPU cgroup controller.

Operations on the CPU controller

getProcessCPUQuota :: IO CPUQuota

Get the current process' CPU quota

getCPUQuota :: Controller CPU -> IO CPUQuota

Read "cpu.cfs_quota_us" and "cpu.cfs_period_us" files into a CPUQuota.

For example:

| cpu.cfs_quota_us | cpu.cfs_period_us | CPUQuota         |
| ---------------- | ----------------- | ---------------- |
|           100000 |            100000 | CPUQuota (1 % 1) |
|           200000 |            100000 | CPUQuota (2 % 1) |
|            50000 |            100000 | CPUQuota (1 % 2) |
|               -1 |            100000 | NoQuota          |

data CPUQuota

A CPU quota is the ratio of CPU time our process can use relative to the scheduler period

For example:

| ratio            | description |
| ---------------- | ----------- |
|  100000 / 100000 |         (1) |
|  200000 / 100000 |         (2) |
|   50000 / 100000 |         (3) |
|     max / 100000 |         (4) |

1. : we can use up to a single CPU core
2. : we can use up to two CPU cores
3. : the scheduler will give us a single CPU core for up to 50% of the time
4. : we can use all available CPU resources (there is no quota)

Constructors

CPUQuota (Ratio Int)

NoQuota

Instances

Show CPUQuota

Defined in System.CGroup.Types

Methods

showsPrec :: Int -> CPUQuota -> ShowS

show :: CPUQuota -> String

showList :: [CPUQuota] -> ShowS

Eq CPUQuota

Defined in System.CGroup.Types

Methods

(==) :: CPUQuota -> CPUQuota -> Bool

(/=) :: CPUQuota -> CPUQuota -> Bool

Ord CPUQuota

Defined in System.CGroup.Types

Methods

compare :: CPUQuota -> CPUQuota -> Ordering

(<) :: CPUQuota -> CPUQuota -> Bool

(<=) :: CPUQuota -> CPUQuota -> Bool

(>) :: CPUQuota -> CPUQuota -> Bool

(>=) :: CPUQuota -> CPUQuota -> Bool

max :: CPUQuota -> CPUQuota -> CPUQuota

min :: CPUQuota -> CPUQuota -> CPUQuota

The CPU cgroup controller

data CPU

The "cpu" cgroup controller

resolveCPUController :: IO (Controller CPU)

Resolve the CPU cgroup controller for the current process

Throws an Exception if the CPU controller is not able to be found, or when running outside of a cgroup