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| author | Peter Zijlstra <peterz@infradead.org> | 2015-07-21 12:13:43 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-08-03 10:57:08 +0200 |
| commit | 0b792bf519e68108d577fcec815ab50913787012 (patch) | |
| tree | 6c7a91eb4963eee386068b5f1afbe66fe4dbcfbe | |
| parent | 3a7651e683701dbb4c7d02e20661c923fa4c6901 (diff) | |
| download | lwn-0b792bf519e68108d577fcec815ab50913787012.tar.gz lwn-0b792bf519e68108d577fcec815ab50913787012.zip | |
locking: Clean up pvqspinlock warning
- Rename the on-stack variable to match the datastructure variable,
- place the cmpxchg back under the comment that explains it,
- clean up the WARN() statement to avoid superfluous conditionals
and line-breaks.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/locking/qspinlock_paravirt.h | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index df19ae4debd0..489a87884337 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -287,20 +287,21 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; struct pv_node *node; - u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0); + u8 locked; /* * We must not unlock if SLOW, because in that case we must first * unhash. Otherwise it would be possible to have multiple @lock * entries, which would be BAD. */ - if (likely(lockval == _Q_LOCKED_VAL)) + locked = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0); + if (likely(locked == _Q_LOCKED_VAL)) return; - if (unlikely(lockval != _Q_SLOW_VAL)) { - if (debug_locks_silent) - return; - WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val)); + if (unlikely(locked != _Q_SLOW_VAL)) { + WARN(!debug_locks_silent, + "pvqspinlock: lock 0x%lx has corrupted value 0x%x!\n", + (unsigned long)lock, atomic_read(&lock->val)); return; } |