From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- arch/tile/lib/spinlock_32.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'arch/tile/lib/spinlock_32.c') diff --git a/arch/tile/lib/spinlock_32.c b/arch/tile/lib/spinlock_32.c index b34f79aad..88c2a5336 100644 --- a/arch/tile/lib/spinlock_32.c +++ b/arch/tile/lib/spinlock_32.c @@ -65,8 +65,17 @@ EXPORT_SYMBOL(arch_spin_trylock); void arch_spin_unlock_wait(arch_spinlock_t *lock) { u32 iterations = 0; - while (arch_spin_is_locked(lock)) + int curr = READ_ONCE(lock->current_ticket); + int next = READ_ONCE(lock->next_ticket); + + /* Return immediately if unlocked. */ + if (next == curr) + return; + + /* Wait until the current locker has released the lock. */ + do { delay_backoff(iterations++); + } while (READ_ONCE(lock->current_ticket) == curr); } EXPORT_SYMBOL(arch_spin_unlock_wait); -- cgit v1.2.3-54-g00ecf