On 2016-04-05 17:36:49 +0300, Alexander Korotkov wrote:
> Could the reason be that we're increasing concurrency for LWLock state
> atomic variable by placing queue spinlock there?
Don't think so, it's the same cache-line either way.
> But I wonder why this could happen during "pgbench -S", because it doesn't
> seem to have high traffic of exclusive LWLocks.
Yea, that confuses me too. I suspect there's some mis-aligned
datastructures somewhere. It's hard to investigate such things without
access to hardware.
(FWIW, I'm working on getting pinunpin committed)
Greetings,
Andres Freund