A set of Linux kernel patches posted back in October for rewriting the kernel’s memory-mapped concurrency ID code for some nice performance wins looks like it will land for Linux 6.19. This is the code that prominent Intel engineer Thomas Gleixner found to yield up to an 18% improvement for the PostgreSQL database. My testing of this “mm/cid” code has also shown some nice performance wins too.

Intel Fellow Thomas Gleixner overhauled the CID management code after finding the existing complex code introduced significant overhead into the kernel scheduler’s hot code paths. This new code is simpler and lower-overhead.