Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\locking\rwsem.c Create Date:2022-07-28 09:48:25
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:lock for writing

Proto:static inline void __down_write(struct rw_semaphore *sem)

Type:void

Parameter:

TypeParameterName
struct rw_semaphore *sem
1388  tmp = RWSEM_UNLOCKED_VALUE
1390  If Value for the false possibility is greater at compile time(!atomic_long_try_cmpxchg_acquire( & count, & tmp, On 64-bit architectures, the bit definitions of the count are:* Bit 0 - writer locked bit* Bit 1 - waiters present bit* Bit 2 - lock handoff bit* Bits 3-7 - reserved* Bits 8-62 - 55-bit reader count* Bit 63 - read fail bit* On 32-bit architectures, the )) Then Wait until we successfully acquire the write lock
1393  Else All writes to owner are protected by WRITE_ONCE() to make sure that* store tearing can't happen as optimistic spinners may read and use* the owner value concurrently without lock