PressureStallInformation QML Type

Provides Linux PSI (Pressure Stall Information) monitoring for a cgroup resource. More...

• List of all members, including inherited members

Properties

• mode : enumeration
• stallTime : int
• timeWindow : int
• type : enumeration

Signals

• triggered()

Detailed Description

This type cannot be instantiated directly. Instances are accessed via the CGroupStatus::cpuPSI, CGroupStatus::memoryPSI, and CGroupStatus::ioPSI properties.

Linux PSI monitoring (available since kernel 4.20 with cgroup v2) detects resource pressure by tracking the time tasks spend stalled waiting for a resource. Set mode to Some or Full and configure timeWindow and stallTime to define the trigger threshold. The triggered signal fires whenever the accumulated stall time within timeWindow exceeds stallTime.

See also CGroupStatus.

Property Documentation

mode : enumeration

Controls whether PSI monitoring is enabled and which stall condition is observed.

See also timeWindow, stallTime, and triggered.

stallTime : int

The stall time threshold in milliseconds. When the accumulated stall time within timeWindow exceeds this value, the triggered signal is emitted.

See also timeWindow and triggered.

timeWindow : int

The observation time window in milliseconds over which stall time is accumulated. When the accumulated stall time within this window exceeds stallTime, the triggered signal is emitted.

See also stallTime and triggered.

type : enumeration

The type of resource this PressureStallInformation instance monitors.

This is a read-only property that is set when the instance is created. It can be used to distinguish between the different PSI types when accessing them via CGroupStatus.

Signal Documentation

triggered()

Emitted when the accumulated stall time within timeWindow exceeds stallTime. Monitoring must be active, i.e. mode must be set to either Some or Full.

See also mode, timeWindow, and stallTime.