search for: queue_spin_lock_slowerpath

...: (*,x,y) +--> (*,0,0) ---> (*,0,1) -' : > * queue : ^--' : > * > + * The pending bit processing is in the trylock_pending() function whereas > + * the uncontended and contended queue processing is in the > + * queue_spin_lock_slowerpath() function. > + * > * This slowpath only contains the faster pending bit and trylock codes. > * The slower queuing code is in the slowerpath function. > */ > @@ -845,7 +844,7 @@ void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val) > > BUILD_BUG_ON(CONFIG_NR_...

...nline void pv_queue_spin_check(struct mcs_spinlock *mcs, + int *count) {} +static inline void pv_halt_check(struct mcs_spinlock *mcs, void *lock) {} +static inline void pv_set_prev(struct mcs_spinlock *mcs, + struct mcs_spinlock *prev) {} +#endif /* CONFIG_PARAVIRT_SPINLOCKS */ + /** * queue_spin_lock_slowerpath - a slower patch for acquiring queue spinlock * @lock: Pointer to queue spinlock structure @@ -260,6 +281,7 @@ static noinline void queue_spin_lock_slowerpath(struct qspinlock *lock, { struct mcs_spinlock *prev, *next; u32 val, old; + int hcnt = 0; /* Queue head loop counter */ /* * w...

On 04/18/2014 05:40 PM, Waiman Long wrote: > On 04/18/2014 03:05 PM, Peter Zijlstra wrote: >> On Fri, Apr 18, 2014 at 01:52:50PM -0400, Waiman Long wrote: >>> I am confused by your notation. >> Nah, I think I was confused :-) Make the 1 _Q_LOCKED_VAL though, as >> that's the proper constant to use. > > Everyone gets confused once in a while:-) I have plenty

On 04/18/2014 05:40 PM, Waiman Long wrote: > On 04/18/2014 03:05 PM, Peter Zijlstra wrote: >> On Fri, Apr 18, 2014 at 01:52:50PM -0400, Waiman Long wrote: >>> I am confused by your notation. >> Nah, I think I was confused :-) Make the 1 _Q_LOCKED_VAL though, as >> that's the proper constant to use. > > Everyone gets confused once in a while:-) I have plenty

v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving performance. - Simplify some of the codes and add more comments. - Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable unfair lock. - Reduce unfair lock slowpath lock stealing frequency depending on its distance from the queue head. - Add performance data for IvyBridge-EX CPU.

v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving performance. - Simplify some of the codes and add more comments. - Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable unfair lock. - Reduce unfair lock slowpath lock stealing frequency depending on its distance from the queue head. - Add performance data for IvyBridge-EX CPU.

N.B. Sorry for the duplicate. This patch series were resent as the original one was rejected by the vger.kernel.org list server due to long header. There is no change in content. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving performance. - Simplify some of the codes and add more comments. - Test for X86_FEATURE_HYPERVISOR CPU feature bit

N.B. Sorry for the duplicate. This patch series were resent as the original one was rejected by the vger.kernel.org list server due to long header. There is no change in content. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving performance. - Simplify some of the codes and add more comments. - Test for X86_FEATURE_HYPERVISOR CPU feature bit

...int unfair_get_lock(struct qspinlock *lock, struct qnode *node, + u32 tail, int count) { return false; } +#endif /* CONFIG_PARAVIRT_UNFAIR_LOCKS */ + /** * get_qlock - Set the lock bit and own the lock * @lock : Pointer to queue spinlock structure @@ -365,11 +503,17 @@ static noinline void queue_spin_lock_slowerpath(struct qspinlock *lock, * if there was a previous node; link it and wait. */ if (old & _Q_TAIL_MASK) { + DEF_LOOP_CNT(cnt); + prev = decode_tail(old); + unfair_set_vars(node, prev, old); ACCESS_ONCE(prev->mcs.next) = (struct mcs_spinlock *)node; - while (!smp_load_acquire(...

v9->v10: - Make some minor changes to qspinlock.c to accommodate review feedback. - Change author to PeterZ for 2 of the patches. - Include Raghavendra KT's test results in patch 18. v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex

v9->v10: - Make some minor changes to qspinlock.c to accommodate review feedback. - Change author to PeterZ for 2 of the patches. - Include Raghavendra KT's test results in patch 18. v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex

v10->v11: - Use a simple test-and-set unfair lock to simplify the code, but performance may suffer a bit for large guest with many CPUs. - Take out Raghavendra KT's test results as the unfair lock changes may render some of his results invalid. - Add PV support without increasing the size of the core queue node structure. - Other minor changes to address some of the

v10->v11: - Use a simple test-and-set unfair lock to simplify the code, but performance may suffer a bit for large guest with many CPUs. - Take out Raghavendra KT's test results as the unfair lock changes may render some of his results invalid. - Add PV support without increasing the size of the core queue node structure. - Other minor changes to address some of the

v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex patches into smaller ones to ease review effort. - Fix a racing condition in the PV qspinlock code. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving

v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex patches into smaller ones to ease review effort. - Fix a racing condition in the PV qspinlock code. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving