When and Why the Go Scheduler Allocates New M and P Processors
Understanding the Go runtime's scheduling model is crucial for optimizing application performance. One key aspect of this model is the allocation of M (machines) and P (processors).
When Are M and P Created?
M processors are created when:
- A new goroutine is started ( unless there is a spare idle M)
- An existing M blocks on an A system call (creates a new operating system thread known as an M)
P processors are created when all the local runqueues are full one goroutine is running its neighbor goroutines ready to run are put in a global queue and it contains a single p.
Blocking Tasks and P Reuse
In the provided test code, the goroutines perform blocking database operations. Blocking tasks remove M processors from P processors.
In this case, creating new M processors is necessary to handle the blocked goroutines. The initial 8 (number of virtual cores) M processors will not be sufficient for the second batch. New M processors will be allocated as needed.
Additional Resources
- https://www.programmersought.com/article/79557885527/
- https://blog.golang.org/go-goroutine-os-thread-and-cpu-management
The above is the detailed content of When and Why Does the Go Scheduler Allocate New M and P Processors?. For more information, please follow other related articles on the PHP Chinese website!

This article explains Go's package import mechanisms: named imports (e.g., import "fmt") and blank imports (e.g., import _ "fmt"). Named imports make package contents accessible, while blank imports only execute t

This article explains Beego's NewFlash() function for inter-page data transfer in web applications. It focuses on using NewFlash() to display temporary messages (success, error, warning) between controllers, leveraging the session mechanism. Limita

This article details efficient conversion of MySQL query results into Go struct slices. It emphasizes using database/sql's Scan method for optimal performance, avoiding manual parsing. Best practices for struct field mapping using db tags and robus

This article demonstrates creating mocks and stubs in Go for unit testing. It emphasizes using interfaces, provides examples of mock implementations, and discusses best practices like keeping mocks focused and using assertion libraries. The articl

This article explores Go's custom type constraints for generics. It details how interfaces define minimum type requirements for generic functions, improving type safety and code reusability. The article also discusses limitations and best practices

This article details efficient file writing in Go, comparing os.WriteFile (suitable for small files) with os.OpenFile and buffered writes (optimal for large files). It emphasizes robust error handling, using defer, and checking for specific errors.

The article discusses writing unit tests in Go, covering best practices, mocking techniques, and tools for efficient test management.

This article explores using tracing tools to analyze Go application execution flow. It discusses manual and automatic instrumentation techniques, comparing tools like Jaeger, Zipkin, and OpenTelemetry, and highlighting effective data visualization


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Dreamweaver CS6
Visual web development tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
