Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\trace\trace.c Create Date:2022-07-28 11:59:45
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:The current tracer is copied to avoid a global locking* all around.

Proto:static void *s_start(struct seq_file *m, loff_t *pos)

Type:void

Parameter:

TypeParameterName
struct seq_file *m
loff_t *pos
3531  iter = private
3532  tr = tr
3533  cpu_file = cpu_file
3534  void * p = NULL
3535  l = 0
3544  mutex_lock( & race_types_lock is used to protect the trace_types list.)
3545  If Value for the false possibility is greater at compile time(current_trace && name != name) Then trace = current_trace
3547  mutex_unlock - release the mutex*@lock: the mutex to be released* Unlock a mutex that has been locked by this task previously.* This function must not be used in interrupt context. Unlocking* of a not locked mutex is not allowed.
3554  If Not it's true when current open file is snapshot Then atomic_inc( & mporary disable recording )
3557  If pos != pos Then
3558  ent = NULL
3559  cpu = 0
3560  idx = -1
3562  If cpu_file == RING_BUFFER_ALL_CPUS Then
3563  for_each_tracing_cpu(cpu)
3564  tracing_iter_reset(iter, cpu)
3565  Else tracing_iter_reset(iter, cpu_file)
3568  leftover = 0
3569  When p && l < pos cycle
3572  Else
3577  If leftover Then p = iter
3579  Else
3580  l = pos - 1
3581  p = s_next(m, p, & l)
3585  trace_event_read_lock()
3586  trace_access_lock(cpu_file)
3587  Return p