Messages in this thread Patch in this message | | | From | Waiman Long <> | Subject | [PATCH tip/locking/core 3/3] locking/pvqspinlock: Direct lock stealing count tracking in pv_queued_spin_steal_lock | Date | Thu, 10 Dec 2015 15:17:46 -0500 |
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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> --- kernel/locking/qspinlock_paravirt.h | 16 +++++++++------- kernel/locking/qspinlock_stat.h | 13 ------------- 2 files changed, 9 insertions(+), 20 deletions(-)
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 72cec9e..21ede57 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 diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h index 283a615..eb2a2c9 100644 --- a/kernel/locking/qspinlock_stat.h +++ b/kernel/locking/qspinlock_stat.h @@ -282,19 +282,6 @@ static inline void __pv_wait(u8 *ptr, u8 val) #define pv_kick(c) __pv_kick(c) #define pv_wait(p, v) __pv_wait(p, v) -/* - * PV unfair trylock count tracking function - */ -static inline int qstat_spin_steal_lock(struct qspinlock *lock) -{ - int ret = pv_queued_spin_steal_lock(lock); - - qstat_inc(qstat_pv_lock_stealing, ret); - return ret; -} -#undef queued_spin_trylock -#define queued_spin_trylock(l) qstat_spin_steal_lock(l) - #else /* CONFIG_QUEUED_LOCK_STAT */ static inline void qstat_inc(enum qlock_stats stat, bool cond) { } -- 1.7.1
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