| Message ID | 1402080497.14433.8.camel@buesod1.americas.hpqcorp.net (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, 2014-06-06 at 11:48 -0700, Davidlohr Bueso wrote: > On Fri, 2014-06-06 at 11:12 -0700, Davidlohr Bueso wrote: > > On Fri, 2014-06-06 at 10:13 -0700, Jason Low wrote: > > > On Fri, 2014-06-06 at 08:55 -0700, Davidlohr Bueso wrote: > > > > Just like with mutexes (CONFIG_MUTEX_SPIN_ON_OWNER), > > > > encapsulate the dependencies for rwsem optimistic spinning. > > > > No logical changes here as it continues to depend on both > > > > SMP and the XADD algorithm variant. > > > > > > > > Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> > > > > --- > > > > include/linux/rwsem.h | 4 ++-- > > > > kernel/Kconfig.locks | 4 ++++ > > > > kernel/locking/rwsem.c | 2 +- > > > > 3 files changed, 7 insertions(+), 3 deletions(-) > > > > > > Do we also want to add an #ifdef CONFIG_RWSEM_SPIN_ON_OWNER in > > > __init_rwsem() and in the optimistic spinning functions for rwsem-xadd? > > > > > > > Not really, as we conditionally build rwsem-xadd.o based on > > CONFIG_RWSEM_XCHGADD_ALGORITHM: > > > > obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o > > obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o > > > > So leaving just SMP is ok there. > > Of course that's bogus when we add more dependencies (ie 2/2), so yeah, > we need to add the whole CONFIG_RWSEM_SPIN_ON_OWNER option. > > Thanks. > diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c > index dacc321..f6b5b96 100644 > --- a/kernel/locking/rwsem-xadd.c > +++ b/kernel/locking/rwsem-xadd.c > @@ -82,7 +82,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, > sem->count = RWSEM_UNLOCKED_VALUE; > raw_spin_lock_init(&sem->wait_lock); > INIT_LIST_HEAD(&sem->wait_list); > -#ifdef CONFIG_SMP > +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER > sem->owner = NULL; > sem->osq = NULL; > #endif And should we also change that in the optimistic spinning functions so that it defaults to: static bool rwsem_optimistic_spin(struct rw_semaphore *sem) { return false; } in the !CONFIG_RWSEM_SPIN_ON_OWNER case. Thanks. > diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c > index 42f806d..e2d3bc7 100644 > --- a/kernel/locking/rwsem.c > +++ b/kernel/locking/rwsem.c > @@ -12,7 +12,7 @@ > > #include <linux/atomic.h> > > -#if defined(CONFIG_SMP) && defined(CONFIG_RWSEM_XCHGADD_ALGORITHM) > +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER > static inline void rwsem_set_owner(struct rw_semaphore *sem) > { > sem->owner = current; -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 8d79708..accdef7 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -27,7 +27,7 @@ struct rw_semaphore { long count; raw_spinlock_t wait_lock; struct list_head wait_list; -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* * Write owner. Used as a speculative check to see * if the owner is running on the cpu. @@ -64,7 +64,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) # define __RWSEM_DEP_MAP_INIT(lockname) #endif -#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER #define __RWSEM_INITIALIZER(name) \ { RWSEM_UNLOCKED_VALUE, \ __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 35536d9..e4c3162 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -224,6 +224,10 @@ config MUTEX_SPIN_ON_OWNER def_bool y depends on SMP && !DEBUG_MUTEXES +config RWSEM_SPIN_ON_OWNER + def_bool y + depends on SMP && RWSEM_XCHGADD_ALGORITHM + config ARCH_USE_QUEUE_RWLOCK bool diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index dacc321..f6b5b96 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -82,7 +82,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, sem->count = RWSEM_UNLOCKED_VALUE; raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER sem->owner = NULL; sem->osq = NULL; #endif diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 42f806d..e2d3bc7 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -12,7 +12,7 @@ #include <linux/atomic.h> -#if defined(CONFIG_SMP) && defined(CONFIG_RWSEM_XCHGADD_ALGORITHM) +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER static inline void rwsem_set_owner(struct rw_semaphore *sem) { sem->owner = current;