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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-09-08 01:01:14 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-09-08 01:01:14 -0300 |
commit | e5fd91f1ef340da553f7a79da9540c3db711c937 (patch) | |
tree | b11842027dc6641da63f4bcc524f8678263304a3 /arch/tile/include/asm/spinlock_32.h | |
parent | 2a9b0348e685a63d97486f6749622b61e9e3292f (diff) |
Linux-libre 4.2-gnu
Diffstat (limited to 'arch/tile/include/asm/spinlock_32.h')
-rw-r--r-- | arch/tile/include/asm/spinlock_32.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/tile/include/asm/spinlock_32.h b/arch/tile/include/asm/spinlock_32.h index c0a77b38d..b14b1ba5b 100644 --- a/arch/tile/include/asm/spinlock_32.h +++ b/arch/tile/include/asm/spinlock_32.h @@ -41,8 +41,12 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock) * to claim the lock is held, since it will be momentarily * if not already. There's no need to wait for a "valid" * lock->next_ticket to become available. + * Use READ_ONCE() to ensure that calling this in a loop is OK. */ - return lock->next_ticket != lock->current_ticket; + int curr = READ_ONCE(lock->current_ticket); + int next = READ_ONCE(lock->next_ticket); + + return next != curr; } void arch_spin_lock(arch_spinlock_t *lock); |