Hi, Andres! On Fri, Nov 4, 2022 at 10:07 PM Andres Freund <and...@anarazel.de> wrote: > The use of cmpxchg vs lock inc/lock add/xadd is one of the major reasons why > lwlocks are slower than a spinlock (but obviously are better under contention > nonetheless). > > > I have a benchmark program that starts a thread for each physical core and > just increments a counter on an atomic value.
Thank you for this insight! I didn't know xadd is much cheaper than cmpxchg unless there are retries. I also wonder how cmpxchg becomes faster with higher concurrency. ------ Regards, Alexander Korotkov
