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[PATCH-tip 0/2] locking/rwsem: Rwsem rearchitecture part 2 follow-up patches

This series contain 2 follow-up patches to alleviate the performance
regression found in the page_fault1 test of the will-it-scale benchmark.
This does not recover all the lost performance, but reclaim a sizeable
portion of it.

The regression was found on an Intel system. I have run the test on
an AMD system. The regression wasn't seen there.  There are only minor
variations in performance. Perhaps the page fault path is quite different
between Intel and AMD systems.

Waiman Long (2):
  locking/rwsem: Clarify usage of owner's nonspinaable bit
  locking/rwsem: Adaptive disabling of reader optimistic spinning

 include/linux/rwsem.h             |   2 +-
 kernel/locking/lock_events_list.h |   9 +-
 kernel/locking/rwsem.c            | 178 +++++++++++++++++++++---------
 3 files changed, 131 insertions(+), 58 deletions(-)