diff options
author | Ingo Molnar <mingo@kernel.org> | 2015-08-25 09:59:19 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-08-25 09:59:19 +0200 |
commit | 8d58b66ed2b000f27658c88a4ed70e8042e86a58 (patch) | |
tree | 5bae2c74f932b5d863f72cb698a6f71260340b26 /arch/tile/include/asm/spinlock_32.h | |
parent | 13fe86f465b72fc9328d4f5ebc33223c011852ae (diff) | |
parent | c13dcf9f2d6f5f06ef1bf79ec456df614c5e058b (diff) |
Merge tag 'v4.2-rc8' into x86/mm, before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 c0a77b38d39a..b14b1ba5bf9c 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); |