System Call Latency

System call latency is the time delay experienced when a user-level application requests a service from the operating system kernel. These requests, such as reading from a network socket or accessing a file, are necessary but time-consuming.

In high-performance trading applications, frequent system calls can create significant overhead, slowing down the execution of the main trading loop. Developers often use techniques like user-space networking to bypass the kernel entirely, allowing the application to interact directly with the network interface card.

This reduces latency by eliminating the need for context switching and kernel-level processing, which is a common practice in building ultra-low-latency trading platforms.