This article explains the fundamentals of Linux interrupt handling, covering the concepts of hardware and software interrupts, the IRQ processing flow, maskable versus non‑maskable interrupts, and the three deferred execution mechanisms—softirq, tasklet, and workqueue—along with code examples and practical considerations.
This article explains the layered architecture of the Linux network subsystem, the TCP/IP model implementation, how hardware and soft interrupts are registered and processed, the role of ksoftirqd and NAPI, and the complete send/receive packet flow from NIC to protocol stack.
This article explains the fundamentals of x86 interrupt handling, covering the distinction between interrupt vectors and descriptors, classification of internal and external interrupts, the role of the 8259A PIC, how interrupt numbers are assigned, and the mechanisms for saving and restoring CPU state during an interrupt.
This article explains Linux's sophisticated scheduling system, CPU context switching, and the architecture of hardware and software interrupts, detailing how the kernel manages CPU resources, interrupt contexts, and bottom‑half mechanisms to optimize performance and stability.
This article presents the complete 1994 assembly source of Lei Jun’s RAMinit TSR program, explains its historical context, describes its hot‑key removal logic, interrupt hooking, environment backup and restoration, and details the low‑level XMS/EMS memory management routines.
This article explains Linux kernel interrupt handling in five stages—from acquiring the interrupt number and serializing concurrent interrupts to using softirqs, tasklets, and workqueues for deferred processing—while highlighting the design choices that keep critical code non‑reentrant and the system responsive.
A developer discovers that clearing the entire ISR register in the RTL8139 driver masks a pending Rx interrupt, causing the first TCP SYN packet to be lost, and resolves the issue by clearing only the TxOK bit.
This guide explains what hardware interrupts are, how SMP IRQ affinity works, and provides step‑by‑step Linux commands to assign specific device IRQs—such as network or disk—to individual CPU cores, improving multi‑core server performance and throughput.
