This article explains how Linux system calls work, compares their overhead to regular function calls, and details the three implementation methods—software interrupts, fast syscall instructions, and the virtual dynamic shared object (vDSO)—including their performance trade‑offs and practical usage.
This article explains how Linux implements system calls via software interrupts, fast syscall/sysenter instructions, and the virtual dynamic shared object (vDSO), comparing their performance to regular function calls and showing concrete code examples and step‑by‑step execution details.
Linux system calls provide the interface between user programs and the kernel, and this article explains the three implementation methods—software interrupts, fast syscall instructions (SYSENTER/SYSCALL), and the virtual dynamic shared object (vDSO)—detailing their operation, performance impact, and relevant assembly code examples.
