search for: config_virt_unfair_lock

...UEST diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index e4a4f5d..448de8b 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -5,6 +5,10 @@ #if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) +#ifdef CONFIG_VIRT_UNFAIR_LOCKS +extern struct static_key virt_unfairlocks_enabled; +#endif + #define queue_spin_unlock queue_spin_unlock /** * queue_spin_unlock - release a queue spinlock @@ -26,4 +30,79 @@ static inline void queue_spin_unlock(struct qspinlock *lock) #include <asm-generic/qspinlock.h> +union arch...

...ended lock-unlock operation by about 1-2% > mainly due to the use of a static key. However, uncontended lock-unlock > operation are really just a tiny percentage of a real workload. So > there should no noticeable change in application performance. No, entirely unacceptable. > +#ifdef CONFIG_VIRT_UNFAIR_LOCKS > +/** > + * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly > + * @lock : Pointer to queue spinlock structure > + * Return: 1 if lock acquired, 0 if failed > + */ > +static __always_inline int queue_spin_trylock_unfair(struct qspinlock *lock) > +{ >...

...ended lock-unlock operation by about 1-2% > mainly due to the use of a static key. However, uncontended lock-unlock > operation are really just a tiny percentage of a real workload. So > there should no noticeable change in application performance. No, entirely unacceptable. > +#ifdef CONFIG_VIRT_UNFAIR_LOCKS > +/** > + * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly > + * @lock : Pointer to queue spinlock structure > + * Return: 1 if lock acquired, 0 if failed > + */ > +static __always_inline int queue_spin_trylock_unfair(struct qspinlock *lock) > +{ >...

...ion by about 1-2% >> mainly due to the use of a static key. However, uncontended lock-unlock >> operation are really just a tiny percentage of a real workload. So >> there should no noticeable change in application performance. > No, entirely unacceptable. > >> +#ifdef CONFIG_VIRT_UNFAIR_LOCKS >> +/** >> + * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly >> + * @lock : Pointer to queue spinlock structure >> + * Return: 1 if lock acquired, 0 if failed >> + */ >> +static __always_inline int queue_spin_trylock_unfair(struct qspinl...

...t;>mainly due to the use of a static key. However, uncontended lock-unlock > >>operation are really just a tiny percentage of a real workload. So > >>there should no noticeable change in application performance. > >No, entirely unacceptable. > > > >>+#ifdef CONFIG_VIRT_UNFAIR_LOCKS > >>+/** > >>+ * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly > >>+ * @lock : Pointer to queue spinlock structure > >>+ * Return: 1 if lock acquired, 0 if failed > >>+ */ > >>+static __always_inline int queue_spin_tryl...

...t;>mainly due to the use of a static key. However, uncontended lock-unlock > >>operation are really just a tiny percentage of a real workload. So > >>there should no noticeable change in application performance. > >No, entirely unacceptable. > > > >>+#ifdef CONFIG_VIRT_UNFAIR_LOCKS > >>+/** > >>+ * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly > >>+ * @lock : Pointer to queue spinlock structure > >>+ * Return: 1 if lock acquired, 0 if failed > >>+ */ > >>+static __always_inline int queue_spin_tryl...

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

...the use of a static key. However, uncontended lock-unlock >>>> operation are really just a tiny percentage of a real workload. So >>>> there should no noticeable change in application performance. >>> No, entirely unacceptable. >>> >>>> +#ifdef CONFIG_VIRT_UNFAIR_LOCKS >>>> +/** >>>> + * queue_spin_trylock_unfair - try to acquire the queue spinlock unfairly >>>> + * @lock : Pointer to queue spinlock structure >>>> + * Return: 1 if lock acquired, 0 if failed >>>> + */ >>>> +static __always_in...