Pressure stall informations (PSI) and starvation notifier

A few readings to getting started with PSI:

• https://docs.kernel.org/accounting/psi.html
• https://facebookmicrosites.github.io/psi/docs/overview
• https://unixism.net/2019/08/linux-pressure-stall-information-psi-by-example/

🚀 Install

go get github.com/samber/go-psi

This library is v1 and follows SemVer strictly. No breaking changes will be made to exported APIs before v2.0.0.

Requires Linux kernel >= 4.20.

💡 Usage

GoDoc: https://pkg.go.dev/github.com/samber/go-psi

Retrieve current PSI state

import "github.com/samber/go-psi"

// Get PSI for a single resource: psi.Memory or psi.CPU or psi.IO.
stats, err := psi.PSIStatsForResource(psi.Memory)

// Get all PSI stats.
all, err := psi.AllPSIStats()

Get PSI change notifications

import "github.com/samber/go-psi"

onChange, done, err := psi.Notify(psi.Memory)

for {
    last, _ := <-onChange
    fmt.Printf("\nMemory:\n%s\n", last)
}

// when you're done, just stop the notifier
done <- struct{}{}

Get PSI starvation alerts

import "github.com/samber/go-psi"

// Alert starts when CPU 10s average go further 90% and stops when CPU goes below 70%.
onAlert, done, err := psi.NotifyStarvation(psi.CPU, psi.Avg10, 70, 90)

for {
    alert, _ := <-onAlert
    fmt.Printf("\nALERT %t\nCPU: %f%%\n", alert.Starved, alert.Current)
}

// when you're done, just stop the notifier
done <- struct{}{}

🤝 Contributing

• Ping me on Twitter @samuelberthe (DMs, mentions, whatever :))
• Fork the project
• Fix open issues or request new features

Don't hesitate ;)

# Install some dev dependencies
make tools

# Run tests
make test
# or
make watch-test

👤 Contributors

💫 Show your support

Give a ⭐️ if this project helped you!

📝 License

Copyright © 2023 Samuel Berthe.

This project is MIT licensed.