[Patch] ARM define atomic_exchange_acq/atomic_exchange_rel to __atomic_exchange_n

[Dinar Temirbulatov]

Abhishek,

>As I said currently __arch_compare_and_exchange_val_32_acq is defined to __sync_val_compare_and_swap ((mem), (oldval), (newval)), which probably uses two dmb.
>Can't __atomic_compare_exchange_n be used and appropriate memodel be specified for acquire and release variants?
Yes, Looks like that makes sense.
                   thanks, Dinar.