Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\locking\rwsem.c Create Date:2022-07-28 09:48:23
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:downgrade a write lock into a read lock* - caller incremented waiting part of count and discovered it still negative* - just wake up any readers at the front of the queue

Proto:static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)

Type:struct rw_semaphore

Parameter:

TypeParameterName
struct rw_semaphore *sem
1327  raw_spin_lock_irqsave( & wait_lock, flags)
1329  If Not list_empty - tests whether a list is empty*@head: the list to test. Then handle the lock release when processes blocked on it that can now run* - if we come here from up_xxxx(), then the RWSEM_FLAG_WAITERS bit must* have been set
1332  raw_spin_unlock_irqrestore( & wait_lock, flags)
1333  wake_up_q( & wake_q)
1335  Return sem
Caller
NameDescribe
__downgrade_writedowngrade write lock to read lock