Commit d8f46c54 authored by Zheng Zengkai's avatar Zheng Zengkai Committed by openeuler-sync-bot
Browse files

Revert "locking/rwsem: Better collate rwsem_read_trylock()" 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7F5L7


CVE: NA

--------------------------------

Revert this patch due to fio performance degradation.
This reverts commit 70e33bec.

Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
(cherry picked from commit 6d20e85f)
parent 19196dd3

kernel/locking/rwsem.c

+7 −8
Original line number Diff line number Diff line
@@ -273,16 +273,9 @@ static inline void rwsem_set_nonspinnable(struct rw_semaphore *sem) 
static inline bool rwsem_read_trylock(struct rw_semaphore *sem)

{

	long cnt = atomic_long_add_return_acquire(RWSEM_READER_BIAS, &sem->count);



	if (WARN_ON_ONCE(cnt < 0))

		rwsem_set_nonspinnable(sem);



	if (!(cnt & RWSEM_READ_FAILED_MASK)) {

		rwsem_set_reader_owned(sem);

		return true;

	}



	return false;

	return !(cnt & RWSEM_READ_FAILED_MASK);

}



/*
@@ -1347,6 +1340,8 @@ static inline void __down_read(struct rw_semaphore *sem) 
	if (!rwsem_read_trylock(sem)) {

		rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE);

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	} else {

		rwsem_set_reader_owned(sem);

	}

}
@@ -1356,6 +1351,8 @@ static inline int __down_read_interruptible(struct rw_semaphore *sem) 
		if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))

			return -EINTR;

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	} else {

		rwsem_set_reader_owned(sem);

	}

	return 0;

}
@@ -1366,6 +1363,8 @@ static inline int __down_read_killable(struct rw_semaphore *sem) 
		if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE)))

			return -EINTR;

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	} else {

		rwsem_set_reader_owned(sem);

	}

	return 0;

}