Restartable Sequences: A Linux Kernel Feature for Lock-Free Thread-Safe Programming
By
grappler
Fresh out the oven, still warm. Top of the tray.
Summary
This article explores restartable sequences (rseq), a Linux kernel feature introduced in version 4.18 (circa 2018) that enables creation of thread-safe data structures without traditional locks or atomic operations, scaling efficiently to many-core microprocessors. The author notes that rseq currently requires handwritten assembly code on Linux, but predicts a future where all operating systems support rseq(), all system programming languages are redesigned to express restartable sequences, and all software is rewritten to use them.
Key quotes
· 4 pulledThe best kept secret at the frontier of system programming right now is the Linux 4.18+ (c. 2018) concept of restartable sequences or rseq for short.
They allow you to create thread-safe data structures without locks or atomics which scale to microprocessors with many cores.
It's currently only possible to use rseq on Linux using handwritten assembly code.
I believe in the future, all operating systems will be updated to support rseq(), all system programming languages will be redesigned to be able to express restartable sequences
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