diff options
| author | Will Deacon <will.deacon@arm.com> | 2018-04-26 12:34:21 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-04-27 09:48:49 +0200 |
| commit | f9c811fac48cfbbfb452b08d1042386947868d07 (patch) | |
| tree | 4e9d9b9c401574c4164802a272d0b6e7a6942b7a /kernel/locking | |
| parent | locking/qspinlock: Kill cmpxchg() loop when claiming lock from head of queue (diff) | |
| download | linux-f9c811fac48cfbbfb452b08d1042386947868d07.tar.xz linux-f9c811fac48cfbbfb452b08d1042386947868d07.zip | |
locking/qspinlock: Use atomic_cond_read_acquire()
Rather than dig into the counter field of the atomic_t inside the
qspinlock structure so that we can call smp_cond_load_acquire(), use
atomic_cond_read_acquire() instead, which operates on the atomic_t
directly.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boqun.feng@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1524738868-31318-8-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/qspinlock.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index b51494a50b1e..56af1fa9874d 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -337,8 +337,8 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) * barriers. */ if (val & _Q_LOCKED_MASK) { - smp_cond_load_acquire(&lock->val.counter, - !(VAL & _Q_LOCKED_MASK)); + atomic_cond_read_acquire(&lock->val, + !(VAL & _Q_LOCKED_MASK)); } /* @@ -441,8 +441,8 @@ queue: * * The PV pv_wait_head_or_lock function, if active, will acquire * the lock and return a non-zero value. So we have to skip the - * smp_cond_load_acquire() call. As the next PV queue head hasn't been - * designated yet, there is no way for the locked value to become + * atomic_cond_read_acquire() call. As the next PV queue head hasn't + * been designated yet, there is no way for the locked value to become * _Q_SLOW_VAL. So both the set_locked() and the * atomic_cmpxchg_relaxed() calls will be safe. * @@ -452,7 +452,7 @@ queue: if ((val = pv_wait_head_or_lock(lock, node))) goto locked; - val = smp_cond_load_acquire(&lock->val.counter, !(VAL & _Q_LOCKED_PENDING_MASK)); + val = atomic_cond_read_acquire(&lock->val, !(VAL & _Q_LOCKED_PENDING_MASK)); locked: /* @@ -469,7 +469,7 @@ locked: /* In the PV case we might already have _Q_LOCKED_VAL set */ if ((val & _Q_TAIL_MASK) == tail) { /* - * The smp_cond_load_acquire() call above has provided the + * The atomic_cond_read_acquire() call above has provided the * necessary acquire semantics required for locking. */ old = atomic_cmpxchg_relaxed(&lock->val, val, _Q_LOCKED_VAL); |