eBPF SoftIRQ
eBPF SoftIRQ
Plugin: ebpf.plugin Module: softirq
Overview
Monitor latency for each SoftIRQ available.
Attach kprobe to internal kernel functions.
This collector is only supported on the following platforms:
- Linux
This collector supports collecting metrics from multiple instances of this integration, including remote instances.
The plugin needs setuid because it loads data inside kernel. Netada sets necessary permission during installation time.
Default Behavior
Auto-Detection
The plugin checks kernel compilation flags (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT), files inside debugfs, and presence of BTF files to decide which eBPF program will be attached.
Limits
The default configuration for this integration does not impose any limits on data collection.
Performance Impact
This thread will add overhead every time that an internal kernel function monitored by this thread is called.
Setup
Prerequisites
Compile kernel
Check if your kernel was compiled with necessary options (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT) in /proc/config.gz or inside /boot/config file. Some cited names can be different accoring preferences of Linux distributions.
When you do not have options set, it is necessary to get the kernel source code from https://kernel.org or a kernel package from your distribution, this last is preferred. The kernel compilation has a well definedd pattern, but distributions can deliver their configuration files
with different names.
Now follow steps:
- Copy the configuration file to /usr/src/linux/.config.
- Select the necessary options: make oldconfig
- Compile your kernel image: make bzImage
- Compile your modules: make modules
- Copy your new kernel image for boot loader directory
- Install the new modules: make modules_install
- Generate an initial ramdisk image (
initrd) if it is necessary. - Update your boot loader
Debug Filesystem
This thread needs to attach a tracepoint to monitor when a process schedule an exit event. To allow this specific feaure, it is necessary to mount debugfs (mount -t debugfs none /sys/kernel/debug/).`
Configuration
File
The configuration file name for this integration is ebpf.d/softirq.conf.
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 ebpf.d/softirq.conf
Options
All options are defined inside section [global].
| Name | Description | Default | Required |
|---|---|---|---|
| update every | Data collection frequency. | 5 | no |
| ebpf load mode | Define whether plugin will monitor the call (entry) for the functions or it will also monitor the return (return). |
entry | no |
| lifetime | Set default lifetime for thread when enabled by cloud. | 300 | no |
Examples
There are no configuration examples.
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 eBPF SoftIRQ instance
These metrics show latest timestamp for each softIRQ available on host.
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|---|---|---|
| system.softirq_latency | soft IRQs | milliseconds |
Alerts
There are no alerts configured by default for this integration.