Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:include\linux\percpu-rwsem.h Create Date:2022-07-28 05:42:29
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:percpu_down_read_trylock

Proto:static inline int percpu_down_read_trylock(struct percpu_rw_semaphore *sem)

Type:int

Parameter:

TypeParameterName
struct percpu_rw_semaphore *sem
63  ret = 1
65  Even if we don't have any preemption, we need preempt disable/enable* to be barriers, so that we don't have things like get_user/put_user* that can cause faults and scheduling migrate into our preempt-protected* region.()
69  __this_cpu_inc( * read_count)
70  If Value for the false possibility is greater at compile time(!_sync_is_idle() - Are readers permitted to use their fastpaths?*@rsp: Pointer to rcu_sync structure to use for synchronization* Returns true if readers are permitted to use their fastpaths. Must be) Then ret = __percpu_down_read(sem, true)
72  preempt_enable()
78  If ret Then rwsem_acquire_read( & dep_map, 0, 1, _RET_IP_)
81  Return ret
Caller
NameDescribe
__sb_start_writeThis is an internal function, please use sb_start_{write,pagefault,intwrite}* instead.