perf_event_free_task

函数名称：Free a context as created by inheritance by perf_event_init_task() below,* used by fork() in case of fail.* Even though the task has never lived, the context and events have been* exposed through the child_list, so we must take care tearing it all down.

函数原型：void perf_event_free_task(struct task_struct *task)

返回类型：void

参数：

类型	参数	名称
struct task_struct *	task

11972

ctx等于perf_event_ctxp[ctxn]

11973

如果非ctx则继续下一循环

11976

mutex_lock( & Protect the list of events. Locking either mutex or lock* is sufficient to ensure the list doesn't change; to change* the list you need to lock both the mutex and the spinlock.)

11977

关闭本地中断，获取所要保护的运行队列（runqueue）的自旋锁（spinlock），为查找可运行进程做准备。( & Protect the states of the events in the list,* nr_active, and the list:)

11984

RCU_INIT_POINTER() - initialize an RCU protected pointer*@p: The pointer to be initialized.*@v: The value to initialized the pointer to.* Initialize an RCU-protected pointer in special cases where readers(perf_event_ctxp[ctxn], NULL)

11985

WRITE_ONCE(task, TASK_TOMBSTONE)

11986

put_task_struct(task)

11987

raw_spin_unlock_irq( & Protect the states of the events in the list,* nr_active, and the list:)

11989

list_for_each_entry_safe - iterate over list of given type safe against removal of list entry*@pos: the type * to use as a loop cursor.*@n: another type * to use as temporary storage*@head: the head for your list.(event, tmp, & event_list, event_entry)

11990

perf_free_event(event, ctx)

11992

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.

12008

wait_var_event( & refcount, _read - get a refcount's value*@r: the refcount* Return: the refcount's value == 1)

12009

**调用者**
名称	描述
perf_event_init_task	进程性能调优

源代码转换工具开放的插件接口	X
支持：c/c++/esqlc/java Oracle/Informix/Mysql 插件可实现：逻辑报告代码生成和批量转换代码