A professional Linux technology community and learning platform covering the kernel, memory management, process management, file system and I/O, performance tuning, device drivers, virtualization, and cloud computing.
This article explains the background, purpose, and detailed implementation of the Linux kernel cgroup freezer subsystem, including its data structures, command‑line usage, signal‑based freeze workflow, and a practical experiment that demonstrates process suspension and power savings on ARM64.
The article explains how PRTOS implements a virtual clock for each partition by intercepting hardware timer events, outlines five key use cases, compares three x86 timer sources (Intel 8253 PIT, TSC, HPET), and details their driver implementations, per‑CPU resource handling, and SMP constraints.
This article explains how PRTOS implements a separated kernel architecture with paravirtualization, details the hardware‑dependency layer, outlines the constraints of embedded virtualization, and walks through CPU frequency calibration and interrupt‑vector initialization for x86‑based embedded hypervisors.
The article examines how Android’s Scudo memory allocator has been refined over the past three years, detailing its four design goals, the cache and thread‑specific data mechanisms for fast allocation, strategies to balance safe memory release with performance, and the group‑based approach that reduces fragmentation while preserving security.
This article explains how to extend eBPF to make virtio‑net NIC queue metrics observable, walks through the front‑end send/receive flow, defines key queue indices, integrates the probes into the rtrace tool, and demonstrates fault detection with real‑time data.
The article provides a detailed technical overview of Linux's new extensible scheduler class SCHED_EXT, explaining its architecture, eBPF‑based customization interfaces, core data structures, queue management, scheduling points, and a central‑scheduler example, while comparing it with traditional CFS and per‑CPU run‑queues.
This article explains the design and implementation of file readahead in the Linux 3.12 kernel, using sequential, random, and multithreaded read scenarios to show how the kernel initializes readahead windows, triggers synchronous and asynchronous prefetches, and updates the page cache.
The Snapdragon 8 Gen 4 brings Android smartphones into the 3nm era, featuring Qualcomm's Nuvia architecture, a 10628 multi‑core score that outperforms Apple’s A17 Pro, LLVM support for the Oryon core, and upcoming flagship launches from Xiaomi and OnePlus, while highlighting the cost and production challenges of 3nm technology.
This article breaks down USB 2.0's four transfer types—Bulk, Control, Interrupt, and Isochronous—detailing their packet structures, transaction stages, error handling, bandwidth limits, and priority rules with concrete examples and diagrams to help engineers design reliable USB devices.
This article breaks down the USB 2.0 communication protocol by explaining how raw serial bits are organized into fields and packets—covering SYNC, PID, address, endpoint, frame number, data, CRC, as well as token, SOF, data, split‑transaction and handshake packets, with concrete examples and timing details.
