Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:include\linux\percpu-refcount.h Create Date:2022-07-28 05:38:02
Last Modify:2020-03-12 14:18:49 Copyright©Brick
home page Tree
Annotation kernel can get tool activityDownload SCCTChinese

Name:percpu_ref_tryget_live - try to increment a live percpu refcount*@ref: percpu_ref to try-get* Increment a percpu refcount unless it has already been killed

Proto:static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)

Type:bool

Parameter:

TypeParameterName
struct percpu_ref *ref
257  __percpu * percpu_count
258  bool ret = false
260  _read_lock() - mark the beginning of an RCU read-side critical section* When synchronize_rcu() is invoked on one CPU while other CPUs* are within RCU read-side critical sections, then the* synchronize_rcu() is guaranteed to block until after all the other
262  If Internal helper. Don't use outside percpu-refcount proper. The* function doesn't return the pointer and let the caller test it for NULL* because doing so forces the compiler to generate two conditional Then
263  this_cpu_inc( * percpu_count)
264  ret = true
265  Else if Not (* The low bit of the pointer indicates whether the ref is in percpu * mode; if set, then get/put will manipulate the atomic_t. & __PERCPU_REF_DEAD) Then
266  ret = atomic_long_inc_not_zero( & count)
269  _read_unlock() - marks the end of an RCU read-side critical section.* In most situations, rcu_read_unlock() is immune from deadlock.* However, in kernels built with CONFIG_RCU_BOOST, rcu_read_unlock()
271  Return ret
Caller
NameDescribe
cgroup1_root_to_useThe guts of cgroup1 mount - find or create cgroup_root to use
cgroup1_get_tree
blk_queue_enterlk_queue_enter() - try to increase q->q_usage_counter*@q: request queue pointer*@flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PREEMPT
lookup_ioctx