[tip: locking/core] locking/rwsem: Fold __down_{read,write}*()

tip-bot2 for Peter Zijlstra
2020-12-09T18:40:04Z

The following commit has been merged into the locking/core branch of tip:

Commit-ID: c995e638ccbbc65a76d1713c4fdcf927e7e2cb83
Gitweb: https://git.kernel.org/tip/c995e638ccbbc65a76d1713c4fdcf927e7e2cb83
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Tue, 08 Dec 2020 10:27:41 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 09 Dec 2020 17:08:47 +01:00

locking/rwsem: Fold __down_{read,write}*()

There's a lot needless duplication in __down_{read,write}*(), cure
that with a helper.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
---
kernel/locking/rwsem.c | 45 ++++++++++++++++++++---------------------
1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 7915456..67ae366 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -1354,32 +1354,29 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
/*
* lock for reading
*/
-static inline void __down_read(struct rw_semaphore *sem)
+static inline int __down_read_common(struct rw_semaphore *sem, int state)
{
if (!rwsem_read_trylock(sem)) {
- rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE);
+ if (IS_ERR(rwsem_down_read_slowpath(sem, state)))
+ return -EINTR;
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
}
+ return 0;
+}
+
+static inline void __down_read(struct rw_semaphore *sem)
+{
+ __down_read_common(sem, TASK_UNINTERRUPTIBLE);
}

static inline int __down_read_interruptible(struct rw_semaphore *sem)
{
- if (!rwsem_read_trylock(sem)) {
- if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))
- return -EINTR;
- DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
- }
- return 0;
+ return __down_read_common(sem, TASK_INTERRUPTIBLE);
}

static inline int __down_read_killable(struct rw_semaphore *sem)
{
- if (!rwsem_read_trylock(sem)) {
- if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE)))
- return -EINTR;
- DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
- }
- return 0;
+ return __down_read_common(sem, TASK_KILLABLE);
}

static inline int __down_read_trylock(struct rw_semaphore *sem)
@@ -1405,22 +1402,26 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
/*
* lock for writing
*/
-static inline void __down_write(struct rw_semaphore *sem)
-{
- if (unlikely(!rwsem_write_trylock(sem)))
- rwsem_down_write_slowpath(sem, TASK_UNINTERRUPTIBLE);
-}
-
-static inline int __down_write_killable(struct rw_semaphore *sem)
+static inline int __down_write_common(struct rw_semaphore *sem, int state)
{
if (unlikely(!rwsem_write_trylock(sem))) {
- if (IS_ERR(rwsem_down_write_slowpath(sem, TASK_KILLABLE)))
+ if (IS_ERR(rwsem_down_write_slowpath(sem, state)))
return -EINTR;
}

return 0;
}

+static inline void __down_write(struct rw_semaphore *sem)
+{
+ __down_write_common(sem, TASK_UNINTERRUPTIBLE);
+}
+
+static inline int __down_write_killable(struct rw_semaphore *sem)
+{
+ return __down_write_common(sem, TASK_KILLABLE);
+}
+
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem);