An Overview of Kernel Lock Improvements [pdf]

Note: for those interested, MCS locks and qspinlocks are discussed in this fine article: http://lwn.net/Articles/590243/

This is great; I'm still reading through, but, I had no idea that the performance drop was that steep!

Can anyone explain the use of 'round-robin' to describe mulit-node scenarios and 'fill-first' for single node scenarios. I initially assumed they were describing thread schedulers, but that doesn't make clear sense in these tests. Thanks in advance.

This is the key: each locker spins on local memory rather than the lock word at page 63.

It would be interesting to see the same benchmarks for more normal amounts of cores. Most system does not have 240 cores, after all..

great