SystemStatus QML Type

Provides information on the status of the system as a whole. More...

• List of all members, including inherited members

Properties

• cpuCores : int
• cpuLoad : real
• cpuPSI : PressureStallInformation
• ioPSI : PressureStallInformation
• memoryMax : int
• memoryPSI : PressureStallInformation
• memoryUsed : int
• roleNames : list<string>

Methods

• void update()

Detailed Description

SystemStatus monitors the running system, providing CPU and memory statistics as well as pressure stall information (PSI). It is the system-wide counterpart to CGroupStatus, which monitors a single Linux control group.

Memory and CPU monitoring

The memoryMax property reports the total amount of physical RAM installed on the system and is constant. The current memory usage and CPU load are available via memoryUsed and cpuLoad, which are updated on every call to update(). Unlike CGroupStatus, there is no system-level equivalent of memory.high, so a memoryHigh property is not exposed.

You can use this type as a MonitorModel data source to record system load over time:

import QtQuick
import QtApplicationManager

MonitorModel {
    SystemStatus {}
}

Alternatively, drive updates yourself with a Timer:

import QtQuick
import QtApplicationManager

SystemStatus { id: systemStatus }

Timer {
    interval: 1000
    running: true
    repeat: true
    onTriggered: systemStatus.update()
}

Pressure stall monitoring

The cpuPSI, memoryPSI, and ioPSI properties each expose a PressureStallInformation object for event-driven pressure monitoring, backed by the kernel's system-wide interfaces at /proc/pressure/cpu, /proc/pressure/memory, and /proc/pressure/io. Configure the desired mode, timeWindow, and stallTime, then connect to the triggered signal to react when the threshold is exceeded:

import QtQuick
import QtApplicationManager

SystemStatus {
    id: systemStatus

    Component.onCompleted: {
        cpuPSI.timeWindow = 2000  // 2 second observation window
        cpuPSI.stallTime = 200    // fire if stalled for 200ms within that window
        cpuPSI.mode = PressureStallInformation.Some
    }
}

Connections {
    target: systemStatus.cpuPSI
    function onTriggered() { console.log("System-wide CPU pressure detected") }
}

See also CGroupStatus, CpuStatus, MemoryStatus, MonitorModel, and PressureStallInformation.

Property Documentation

cpuCores : int [read-only]

The number of physical CPU cores installed on the system.

cpuLoad : real [read-only]

The overall system CPU utilization between the two most recent calls to update(), as a value ranging from 0 (inclusive, completely idle) to 1 (inclusive, all CPU cores fully busy).

See also update() and cpuCores.

cpuPSI : PressureStallInformation [read-only]

Provides access to system-wide CPU pressure stall monitoring, backed by /proc/pressure/cpu. Monitors situations where tasks anywhere on the system are delayed waiting for CPU time.

Only functional on Linux when the kernel has PSI support enabled.

See also PressureStallInformation, memoryPSI, and ioPSI.

ioPSI : PressureStallInformation [read-only]

Provides access to system-wide I/O pressure stall monitoring, backed by /proc/pressure/io. Monitors situations where tasks anywhere on the system are delayed waiting for I/O.

Only functional on Linux when the kernel has PSI support enabled.

See also PressureStallInformation, cpuPSI, and memoryPSI.

memoryMax : int [read-only]

The total amount of physical memory (RAM) installed on the system, in bytes. This is the system-wide analog of CGroupStatus::memoryMax.

memoryPSI : PressureStallInformation [read-only]

Provides access to system-wide memory pressure stall monitoring, backed by /proc/pressure/memory. Monitors situations where tasks anywhere on the system are delayed waiting for memory.

Only functional on Linux when the kernel has PSI support enabled.

See also PressureStallInformation, cpuPSI, and ioPSI.

memoryUsed : int [read-only]

The amount of physical memory currently in use system-wide, in bytes. Refreshed on every call to update().

See also update() and memoryMax.

roleNames : list<string> [read-only]

Names of the roles provided by SystemStatus when used as a MonitorModel data source.

See also MonitorModel.

Method Documentation

void update()

Updates the memoryUsed and cpuLoad properties.

See also memoryUsed and cpuLoad.