tree 81cb77f31a841e87cecb9329f26e6524cc44f3a2
parent 083986e8248d978b6c961d3da6beb0c921c68220
author Heiko Carstens <heiko.carstens@de.ibm.com> 1379933996 +0200
committer Heiko Carstens <heiko.carstens@de.ibm.com> 1380365184 +0200

lockref: use arch_mutex_cpu_relax() in CMPXCHG_LOOP()

Make use of arch_mutex_cpu_relax() so architectures can override the
default cpu_relax() semantics.
This is especially useful for s390, where cpu_relax() means that we
yield() the current (virtual) cpu and therefore is very expensive,
and would contradict the whole purpose of the lockless cmpxchg loop.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>