Hi,
> I landed on the idea of adding some intentional spinlock
> contention to src/test/modules/test_shm_mq, which is a prefab test
> framework for passing data among multiple worker processes. The
> attached quick-hack patch makes it grab and release a spinlock once
> per passed message.
I wonder if this will show the full set of spinlock contention issues - isn't
this only causing contention for one spinlock between two processes? It's not
too hard to imagine delays being more important the more processes contend for
one cacheline. I only skimmed your changes, so I might also just have
misunderstood what you were doing...
Greetings,
Andres Freund