search for: arch_spin_relax

...rch_rwlock_t *lock); > +#else /* SPLPAR */ > +#define __spin_yield(x) barrier() > +#define __rw_yield(x) barrier() > +#define SHARED_PROCESSOR 0 > +#endif > + > +#ifdef CONFIG_QUEUED_SPINLOCKS > +#include <asm/qspinlock.h> > +#else > + > +#define arch_spin_relax(lock) __spin_yield(lock) > + > static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) > { > return lock.slock == 0; > @@ -114,18 +131,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) > * held. Conveniently, we have a word in the paca that...

...rch_rwlock_t *lock); > +#else /* SPLPAR */ > +#define __spin_yield(x) barrier() > +#define __rw_yield(x) barrier() > +#define SHARED_PROCESSOR 0 > +#endif > + > +#ifdef CONFIG_QUEUED_SPINLOCKS > +#include <asm/qspinlock.h> > +#else > + > +#define arch_spin_relax(lock) __spin_yield(lock) > + > static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) > { > return lock.slock == 0; > @@ -114,18 +131,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) > * held. Conveniently, we have a word in the paca that...

...yield(arch_spinlock_t *lock); +extern void __rw_yield(arch_rwlock_t *lock); +#else /* SPLPAR */ +#define __spin_yield(x) barrier() +#define __rw_yield(x) barrier() +#define SHARED_PROCESSOR 0 +#endif + +#ifdef CONFIG_QUEUED_SPINLOCKS +#include <asm/qspinlock.h> +#else + +#define arch_spin_relax(lock) __spin_yield(lock) + static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) { return lock.slock == 0; @@ -114,18 +131,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) * held. Conveniently, we have a word in the paca that holds this * value. */ - -...

...p) + : "r"(&rw->lock) + : "cr0", "xer", "memory"); +} + +static inline void arch_write_unlock(arch_rwlock_t *rw) +{ + __asm__ __volatile__("# write_unlock\n\t" + PPC_RELEASE_BARRIER: : :"memory"); + rw->lock = 0; +} + +#define arch_spin_relax(lock) spin_yield(lock) +#define arch_read_relax(lock) rw_yield(lock) +#define arch_write_relax(lock) rw_yield(lock) + +/* See include/linux/spinlock.h */ +#define smp_mb__after_spinlock() smp_mb() + +#endif /* __KERNEL__ */ +#endif /* __ASM_SIMPLE_SPINLOCK_H */ diff --git a/arch/powerpc/include/a...

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

v2 is updated to account for feedback from Will, Peter, and Waiman (thank you), and trims off a couple of RFC and unrelated patches. Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued

Updated with everybody's feedback (thanks all), and more performance results. What I've found is I might have been measuring the worst load point for the paravirt case, and by looking at a range of loads it's clear that queued spinlocks are overall better even on PV, doubly so when you look at the generally much improved worst case latencies. I have defaulted it to N even though

This series adds an option to use queued spinlocks for powerpc, and makes it the default for the Book3S-64 subarch. This effort starts with the generic code so it's very simple but still very performant. There are optimisations that can be made to slowpaths, but I think it's better to attack those incrementally if/when we find things, and try to add the improvements to generic code as

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt