SoftIRQ statistics

Plugin: proc.plugin Module: /proc/softirqs

Overview

In the Linux kernel, handling of hardware interrupts is split into two halves: the top half and the bottom half. The top half is the routine that responds immediately to an interrupt, while the bottom half is deferred to be processed later.

Softirqs are a mechanism in the Linux kernel used to handle the bottom halves of interrupts, which can be deferred and processed later in a context where it's safe to enable interrupts.

The actual work of handling the interrupt is offloaded to a softirq and executed later when the system decides it's a good time to process them. This helps to keep the system responsive by not blocking the top half for too long, which could lead to missed interrupts.

Monitoring /proc/softirqs is useful for:

• Performance tuning: A high rate of softirqs could indicate a performance issue. For instance, a high rate of network softirqs (NET_RX and NET_TX) could indicate a network performance issue.

• Troubleshooting: If a system is behaving unexpectedly, checking the softirqs could provide clues about what is going on. For example, a sudden increase in block device softirqs (BLOCK) might indicate a problem with a disk.

• Understanding system behavior: Knowing what types of softirqs are happening can help you understand what your system is doing, particularly in terms of how it's interacting with hardware and how it's handling interrupts.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

This integration doesn't support auto-detection.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per SoftIRQ statistics instance

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
system.softirqs	a dimension per softirq	softirqs/s

Per cpu core

Labels:

Label	Description
cpu	TBD

Metrics:

Metric	Dimensions	Unit
cpu.softirqs	a dimension per softirq	softirqs/s

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

No action required.

Configuration

File

There is no configuration file.

Options

There are no configuration options.

Examples

There are no configuration examples.