There has been more discussion along the lines of per-numa-node and per-
process tables to reduce false-sharing on the futex hash table, but the
effect is similar. One thing I feel is lacking a use-case that exemplifies
the contention on the hash-table and any cache-ping-pong it may cause on
multi-socket and/or multi-node systems. I'm working on a futex test suite
now and I hope some of the perf and stress tests will help here.