diff options
| author | Waiman Long <Waiman.Long@hpe.com> | 2015-12-10 15:17:46 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-29 10:02:41 +0100 |
| commit | eaff0e7003cca6c2748b67ead2d4b1a8ad858fc7 (patch) | |
| tree | 8b081a7e1cf7e9dadad408861193269ad03749e0 /kernel/locking/qspinlock_paravirt.h | |
| parent | 920c720aa5aa3900a7f1689228fdfc2580a91e7e (diff) | |
| download | lwn-eaff0e7003cca6c2748b67ead2d4b1a8ad858fc7.tar.gz lwn-eaff0e7003cca6c2748b67ead2d4b1a8ad858fc7.zip | |
locking/pvqspinlock: Move lock stealing count tracking code into pv_queued_spin_steal_lock()
This patch moves the lock stealing count tracking code into
pv_queued_spin_steal_lock() instead of via a jacket function simplifying
the code.
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1449778666-13593-3-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/qspinlock_paravirt.h')
| -rw-r--r-- | kernel/locking/qspinlock_paravirt.h | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 87bb235c3448..78f04a232d3a 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -55,6 +55,11 @@ struct pv_node { }; /* + * Include queued spinlock statistics code + */ +#include "qspinlock_stat.h" + +/* * By replacing the regular queued_spin_trylock() with the function below, * it will be called once when a lock waiter enter the PV slowpath before * being queued. By allowing one lock stealing attempt here when the pending @@ -65,9 +70,11 @@ struct pv_node { static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; + int ret = !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && + (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0); - return !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && - (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0); + qstat_inc(qstat_pv_lock_stealing, ret); + return ret; } /* @@ -138,11 +145,6 @@ static __always_inline int trylock_clear_pending(struct qspinlock *lock) #endif /* _Q_PENDING_BITS == 8 */ /* - * Include queued spinlock statistics code - */ -#include "qspinlock_stat.h" - -/* * Lock and MCS node addresses hash table for fast lookup * * Hashing is done on a per-cacheline basis to minimize the need to access |