Linux kernel SLAB allocator statistics

Plugin: slabinfo.plugin Module: slabinfo.plugin

Overview

Collects metrics on kernel SLAB cache utilization to monitor the low-level performance impact of workloads in the kernel.

The plugin parses /proc/slabinfo

This collector is only supported on the following platforms:

• Linux

This collector only supports collecting metrics from a single instance of this integration.

This integration requires read access to /proc/slabinfo, which is accessible only to the root user by default. Netdata uses Linux Capabilities to give the plugin access to this file. CAP_DAC_READ_SEARCH is added automatically during installation. This capability allows bypassing file read permission checks and directory read and execute permission checks. If file capabilities are not usable, then the plugin is instead installed with the SUID bit set in permissions sVko that it runs as root.

Default Behavior

Auto-Detection

Due to the large number of metrics generated by this integration, it is disabled by default and must be manually enabled inside /etc/netdata/netdata.conf

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.

Setup

Prerequisites

Minimum setup

If you installed netdata using a package manager, it is also necessary to install the package netdata-plugin-slabinfo.

Configuration

Options

The main configuration file.

Option	Description	Default	Required
Enable plugin	As described above plugin is disabled by default, this option is used to enable plugin.	no	yes

via File

The configuration file name for this integration is netdata.conf. Configuration for this specific integration is located in the [plugins] section within that file.

The file format is a modified INI syntax. The general structure is:

[section1]
    option1 = some value
    option2 = some other value

[section2]
    option3 = some third value

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config netdata.conf

Examples

There are no configuration examples.

Alerts

There are no alerts configured by default for this integration.

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.

SLAB cache utilization metrics for the whole system.

Per Linux kernel SLAB allocator statistics instance

This scope has no labels.

Metrics:

Metric	Description	Dimensions	Unit
mem.slabmemory	Memory Usage	a dimension per cache	B
mem.slabfilling	Object Filling	a dimension per cache	%
mem.slabwaste	Memory waste	a dimension per cache	B