June 20, 2026
Fast rings, furious arguments
Epoll vs. Io_uring in Linux
Linux’s old favorite gets roasted as the "faster" new kid sparks security panic
TLDR: The project switched from Linux’s older traffic-handling system to io_uring, a newer approach that can boost speed by reducing extra work. Commenters loved the performance gains but instantly split into camps over security risks, missing optimizations, and whether the benchmarks proved anything at all.
What should have been a nerdy story about speeding up a student-built server turned into a full-on comment-section cage match. The article itself is simple enough: a teacher and students built a tiny reverse proxy, realized it was getting smoked by giants like nginx and HAProxy, upgraded from the older Linux method called epoll to the newer io_uring, and saw a big speed jump. In plain English: they swapped an older way of handling lots of internet traffic for a newer one designed to cut down on extra trips between an app and the operating system.
But the crowd was not content to just clap for better numbers. One camp basically yelled, “Yep, io_uring is faster, end of story,” with one commenter claiming about 20% more requests per second. Then came the twist: that same speed boost got hit with a giant asterisk, because critics said io_uring is disabled in many places for security reasons, making the shiny new winner feel a bit like a sports car with questionable brakes. Suddenly the vibe shifted from “look at this cool upgrade” to “is this thing too dangerous to trust?”
And then the armchair coaches arrived. One commenter waved the Boost Asio flag for C++ fans, another said the whole benchmark war misses the bigger picture, and one repo snoop basically went, “Cute results, but did you even do CPU pinning?” Even the optimization gremlins showed up with Concurrency Kit and mimalloc recommendations like they were dropping secret cheat codes. The biggest meme of the thread? Every performance victory comes with five people explaining why it doesn’t count.
Key Points
- •The article uses the development of the TinyGate reverse proxy to frame a comparison between epoll and io_uring on Linux.
- •A second TinyGate implementation based on epoll significantly improved performance over the original worker-based version.
- •The article says epoll is readiness-based and typically requires additional read()/write() syscalls after notification, increasing user-kernel context-switch overhead.
- •The article says io_uring is completion-based, uses shared-memory ring buffers, and can batch submissions and completions through io_uring_enter().
- •The article states io_uring is available on Linux kernel 5.1+ and argues that on newer systems it is often preferable to epoll for asynchronous I/O.