[PATCH 01/11] locking, rwsem: get rid of __down_write_nested

Michal Hocko
2016-02-29T12:58:15Z

From: Michal Hocko <mhocko@suse.com>

This is no longer used anywhere and all callers (__down_write) use
0 as a subclass. Ditch __down_write_nested to make the code easier
to follow.

This shouldn't introduce any functional change.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
arch/s390/include/asm/rwsem.h | 7 +------
arch/sh/include/asm/rwsem.h | 5 -----
arch/sparc/include/asm/rwsem.h | 7 +------
arch/x86/include/asm/rwsem.h | 7 +------
include/asm-generic/rwsem.h | 7 +------
include/linux/rwsem-spinlock.h | 1 -
kernel/locking/rwsem-spinlock.c | 7 +------
7 files changed, 5 insertions(+), 36 deletions(-)

diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index 4b43ee7e6776..8e52e72f3efc 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -90,7 +90,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+static inline void __down_write(struct rw_semaphore *sem)
{
signed long old, new, tmp;

@@ -108,11 +108,6 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
rwsem_down_write_failed(sem);
}

-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
diff --git a/arch/sh/include/asm/rwsem.h b/arch/sh/include/asm/rwsem.h
index edab57265293..a5104bebd1eb 100644
--- a/arch/sh/include/asm/rwsem.h
+++ b/arch/sh/include/asm/rwsem.h
@@ -114,11 +114,6 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
rwsem_downgrade_wake(sem);
}

-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
-{
- __down_write(sem);
-}
-
/*
* implement exchange and add functionality
*/
diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h
index 069bf4d663a1..e5a0d575bc7f 100644
--- a/arch/sparc/include/asm/rwsem.h
+++ b/arch/sparc/include/asm/rwsem.h
@@ -45,7 +45,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+static inline void __down_write(struct rw_semaphore *sem)
{
long tmp;

@@ -55,11 +55,6 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
rwsem_down_write_failed(sem);
}

-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
long tmp;
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index ceec86eb68e9..4a8292a0d6e1 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -99,7 +99,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+static inline void __down_write(struct rw_semaphore *sem)
{
long tmp;
asm volatile("# beginning down_write\n\t"
@@ -116,11 +116,6 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
: "memory", "cc");
}

-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index d6d5dc98d7da..b8d8a6cf4ca8 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -53,7 +53,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+static inline void __down_write(struct rw_semaphore *sem)
{
long tmp;

@@ -63,11 +63,6 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
rwsem_down_write_failed(sem);
}

-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
long tmp;
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
index 561e8615528d..a733a5467e6c 100644
--- a/include/linux/rwsem-spinlock.h
+++ b/include/linux/rwsem-spinlock.h
@@ -34,7 +34,6 @@ struct rw_semaphore {
extern void __down_read(struct rw_semaphore *sem);
extern int __down_read_trylock(struct rw_semaphore *sem);
extern void __down_write(struct rw_semaphore *sem);
-extern void __down_write_nested(struct rw_semaphore *sem, int subclass);
extern int __down_write_trylock(struct rw_semaphore *sem);
extern void __up_read(struct rw_semaphore *sem);
extern void __up_write(struct rw_semaphore *sem);
diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c
index 3a5048572065..bab26104a5d0 100644
--- a/kernel/locking/rwsem-spinlock.c
+++ b/kernel/locking/rwsem-spinlock.c
@@ -191,7 +191,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
/*
* get a write lock on the semaphore
*/
-void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
+void __sched __down_write(struct rw_semaphore *sem)
{
struct rwsem_waiter waiter;
struct task_struct *tsk;
@@ -227,11 +227,6 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
}

-void __sched __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
--
2.7.0