From: Rik van Riel <riel@redhat.com>
Here is an incremental fix to the add-sem_is_read-write_locked patch in
-mm.
The reason for this change is that a lock that's held for reading can be
negative when there is a writer waiting, as David pointed out to me a while
ago.
The corresponding change to swaptoken-tuning.patch is in the
next mail.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
include/asm-alpha/rwsem.h | 9 ++-------
include/asm-i386/rwsem.h | 9 ++-------
include/asm-ia64/rwsem.h | 9 ++-------
include/asm-ppc/rwsem.h | 9 ++-------
include/asm-ppc64/rwsem.h | 7 +------
include/asm-s390/rwsem.h | 9 ++-------
include/asm-sh/rwsem.h | 9 ++-------
include/asm-sparc64/rwsem.h | 9 ++-------
include/asm-x86_64/rwsem.h | 9 ++-------
9 files changed, 17 insertions(+), 62 deletions(-)
diff -puN include/asm-alpha/rwsem.h~add-sem_is_read-write_locked-fix include/asm-alpha/rwsem.h
--- devel/include/asm-alpha/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-alpha/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -262,14 +262,9 @@ static inline long rwsem_atomic_update(l
#endif
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-i386/rwsem.h~add-sem_is_read-write_locked-fix include/asm-i386/rwsem.h
--- devel/include/asm-i386/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-i386/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -284,14 +284,9 @@ LOCK_PREFIX "xadd %0,(%2)"
return tmp+delta;
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-ia64/rwsem.h~add-sem_is_read-write_locked-fix include/asm-ia64/rwsem.h
--- devel/include/asm-ia64/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-ia64/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -186,14 +186,9 @@ __downgrade_write (struct rw_semaphore *
#define rwsem_atomic_add(delta, sem) atomic64_add(delta, (atomic64_t *)(&(sem)->count))
#define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* _ASM_IA64_RWSEM_H */
diff -puN include/asm-ppc64/rwsem.h~add-sem_is_read-write_locked-fix include/asm-ppc64/rwsem.h
--- devel/include/asm-ppc64/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-ppc64/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -165,12 +165,7 @@ static inline int rwsem_atomic_update(in
static inline int sem_is_read_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-ppc/rwsem.h~add-sem_is_read-write_locked-fix include/asm-ppc/rwsem.h
--- devel/include/asm-ppc/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-ppc/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -168,14 +168,9 @@ static inline int rwsem_atomic_update(in
return atomic_add_return(delta, (atomic_t *)(&sem->count));
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-s390/rwsem.h~add-sem_is_read-write_locked-fix include/asm-s390/rwsem.h
--- devel/include/asm-s390/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-s390/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -351,14 +351,9 @@ static inline long rwsem_atomic_update(l
return new;
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-sh/rwsem.h~add-sem_is_read-write_locked-fix include/asm-sh/rwsem.h
--- devel/include/asm-sh/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-sh/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -166,14 +166,9 @@ static inline int rwsem_atomic_update(in
return atomic_add_return(delta, (atomic_t *)(&sem->count));
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-sparc64/rwsem.h~add-sem_is_read-write_locked-fix include/asm-sparc64/rwsem.h
--- devel/include/asm-sparc64/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-sparc64/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -56,14 +56,9 @@ static inline void rwsem_atomic_add(int
atomic_add(delta, (atomic_t *)(&sem->count));
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
diff -puN include/asm-x86_64/rwsem.h~add-sem_is_read-write_locked-fix include/asm-x86_64/rwsem.h
--- devel/include/asm-x86_64/rwsem.h~add-sem_is_read-write_locked-fix 2005-09-04 12:55:36.000000000 -0700
+++ devel-akpm/include/asm-x86_64/rwsem.h 2005-09-04 12:55:36.000000000 -0700
@@ -274,14 +274,9 @@ LOCK_PREFIX "xaddl %0,(%2)"
return tmp+delta;
}
-static inline int sem_is_read_locked(struct rw_semaphore *sem)
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
{
- return (sem->count > 0);
-}
-
-static inline int sem_is_write_locked(struct rw_semaphore *sem)
-{
- return (sem->count < 0);
+ return (sem->count != 0);
}
#endif /* __KERNEL__ */
_