Hi Dave, this patch removes the lock you saw with will-it-scale/page_fault2 entirely, is there a chance you could give it a spin? It's based on v3.17-rc4-mmots-2014-09-12-17-13-4 and that memcg THP fix. That kernel also includes the recent root-memcg revert, so you'd have to run it in a memcg; which is as easy as: mkdir /sys/fs/cgroup/memory/foo echo $$ >/sys/fs/cgroup/memory/foo/tasks perf record -g -a ./runtest.py page_fault2 Thanks! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>