Cloudflare launches SOCKMAP, a new TCP splicing mechanism
Cloudflare unveiled SOCKMAP, a kernel‑level TCP splicing feature that cuts latency and streamlines connection handling for high‑performance networking stacks. The code is open for testing and review.
Cloudflare has opened SOCKMAP, a kernel‑level TCP splicing mechanism that moves data directly between sockets without crossing user space. Built on top of the existing TCP stack, SOCKMAP leverages eBPF hooks to route packets inside the kernel, cutting the number of memory copies per connection [Cloudflare Blog].
The code is published in Cloudflare’s open‑source repository and can be compiled on recent Linux kernels. Early testing shows latency reductions of several microseconds per round‑trip and lower CPU usage for high‑throughput services. The feature is currently available for evaluation via a kernel module and a set of example programs [Cloudflare Blog].
Why it matters: By eliminating user‑space copies, SOCKMAP frees CPU cycles for application logic, which is critical for low‑latency services such as real‑time gaming, financial trading, and edge‑cached content delivery. The approach also simplifies the networking stack for developers who can now splice TCP streams with a single system call, reducing code complexity and potential bugs.
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