Commit ab306cae authored Mar 30, 2012 by Chris Metcalf

arch/tile: use atomic exchange in arch_write_unlock()

This idiom is used elsewhere when we do an unlock by writing a zero,
but I missed it here. Using an atomic operation avoids waiting
on the write buffer for the unlocking write to be sent to the home cache.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

parent b14f2190

arch/tile/include/asm/spinlock_64.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -137,7 +137,7 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
		static inline void arch_write_unlock(arch_rwlock_t *rw)
		{
		__insn_mf();
		rw->lock = 0;
		__insn_exch4(&rw->lock, 0); /* Avoid waiting in the write buffer. */
		}

		static inline int arch_read_trylock(arch_rwlock_t *rw)