In this last part of The Implementation of epoll series, I will be explaining how epoll transfers events from kernel space to user space and how different triggering modes were implemented. This fifth article is written way much later than the forth one, and I do apologize for the delay.

In the last two posts, I talked about how epoll works as a whole and how epoll receives new event notification from the monitored file descriptors. In this post, I will be talking about how epoll stores those event notifications and how does the user application retrieves them later. The

The ep_insert() Function ep_insert() is one of the most important functions within the epoll implementation. Understanding what it does is crucial of understanding how epoll receives new events from the monitored files. The definition of ep_insert() is at fs/eventpoll.c, line 1267. Here are some snippets

In this series of blog posts, I will be taking notes about the internals and implementation details of the Linux event poll (epoll) subsystem. Prerequisites Please note that I am assuming the audiences of those articles are familiar with epoll APIs and usages. I will be focusing on the actual