tile: modify arch_spin_unlock_wait() semantics
authorChris Metcalf <cmetcalf@ezchip.com>
Tue, 28 Apr 2015 17:02:26 +0000 (13:02 -0400)
committerChris Metcalf <cmetcalf@ezchip.com>
Wed, 29 Apr 2015 02:43:13 +0000 (22:43 -0400)
commit14c3dec2a875d898262be79c0f85e5f2b70a71b0
tree19bd68642900f5e232d0eaaa7283690b68af8135
parentb787f68c36d49bb1d9236f403813641efa74a031
tile: modify arch_spin_unlock_wait() semantics

Rather than trying to wait until all possible lockers have
unlocked the lock, we now only wait until the current locker
(if any) has released the lock.

The old code was correct, but the new code works more like the x86
code and thus hopefully is more appropriate under contention.
See commit 78bff1c8684f ("x86/ticketlock: Fix spin_unlock_wait()
livelock") for x86.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
arch/tile/lib/spinlock_32.c
arch/tile/lib/spinlock_64.c