On Wed, 20 Sep 2017, Andrea Parri wrote:
Instead, how about just removing the release from
atomic_long_sub_return_release()
such that the osq load is not hoisted over the atomic compound (along with
Peter's
comment):
This solution will actually enforce a stronger (full) ordering w.r.t. the
solution described by Prateek and Peter. Also, it will "trade" two lwsync
for two sync (powerpc), one dmb.ld for one dmb (arm64).
What are the reasons you would prefer this?
It was mainly to maintain consistency about dealing with sem->count, but sure
I won't argue with the above.
