Tag

PID

1 views collected around this technical thread.

Refining Core Development Skills
Refining Core Development Skills
Jul 11, 2023 · Fundamentals

Why the Linux Kernel Replaced PID Bitmap with a Radix Tree and Its Performance Impact

This article explains the Linux kernel's transition from bitmap‑based PID allocation to a radix‑tree (IDR) implementation, describes the underlying data structures and code changes, and presents benchmark results showing roughly a 50% performance improvement for common utilities.

BitmapKernelLinux
0 likes · 18 min read
Why the Linux Kernel Replaced PID Bitmap with a Radix Tree and Its Performance Impact
IT Services Circle
IT Services Circle
Mar 12, 2022 · Fundamentals

Understanding the Misleading ENOMEM Error in Linux Process Creation

This article analyzes why Linux reports "fork: cannot allocate memory" when the real issue is an excessive number of threads or PID allocation failures, explains the kernel's do_fork and alloc_pid implementations, and offers guidance for diagnosing and fixing such misleading ENOMEM errors.

ENOMEMKernelLinux
0 likes · 11 min read
Understanding the Misleading ENOMEM Error in Linux Process Creation
Refining Core Development Skills
Refining Core Development Skills
Mar 7, 2022 · Fundamentals

Understanding Linux fork, alloc_pid and the Misleading ENOMEM Error

The article explains why Linux reports "fork: cannot allocate memory" when the real issue is PID allocation failure caused by excessive threads, analyzes the kernel's do_fork and alloc_pid implementations, and shows that newer kernels still return ENOMEM for non‑memory errors.

ENOMEMKernelLinux
0 likes · 13 min read
Understanding Linux fork, alloc_pid and the Misleading ENOMEM Error
Ctrip Technology
Ctrip Technology
Nov 5, 2020 · Operations

Applying PID Control Algorithm for Advertising Cost Control in Real-Time Bidding Systems

This article explains how the classic PID feedback control algorithm can be adapted to regulate advertising bidding costs, describing its theory, component effects, practical implementation in a real‑time ad‑exchange, simulation experiments, and the resulting improvements in budget adherence and cost stability.

AlgorithmPIDReal-Time Bidding
0 likes · 13 min read
Applying PID Control Algorithm for Advertising Cost Control in Real-Time Bidding Systems