compiler: Alpha respoects load-to-store control dependencies
Section 5.6.1.7 of the Alpha Architecture Manual clearly states that
Alpha respects load-to-store address, data, and control dependencies.
Therefore, READ_ONCE_CTRL() does not need any sort of memory barrier, even
for Alpha. This commit therefore removes the smp_read_barrier_depends().
Sadly, this applies only to load-to-store situations, not to load-to-load
situations, so rcu_dereference()'s smp_read_barrier_depends() must remain.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
1 file changed
