函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\trace\ring_buffer.c Create Date:2022-07-27 12:58:58
Last Modify:2020-03-17 19:30:04 Copyright©Brick
首页 函数Tree
注解内核,赢得工具下载SCCTEnglish

函数名称：rb_allocate_cpu_buffer

函数原型：static struct ring_buffer_per_cpu *rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)

返回类型：struct ring_buffer_per_cpu

参数：

类型参数名称
struct ring_buffer *buffer
longnr_pages
intcpu
1293  cpu_buffer等于根据内存节点分配内存
1295  如果非cpu_buffer则返回:NULL
1298  cpu等于cpu
1299  buffer等于buffer
1300  raw_spin_lock_init( & serialize readers )
1301  lockdep_set_class( & serialize readers , reader_lock_key)
1302  lock = (arch_spinlock_t)
1303  INIT_WORK( & update_pages_work, update_pages_handler)
1304  init_completion( & update_done)
1305  init_irq_work( & work, _wake_up_waiters - wake up tasks waiting for ring buffer input* Schedules a delayed work to wake up any task that is blocked on the* ring buffer waiters queue.)
1306  init_waitqueue_head( & waiters)
1307  init_waitqueue_head( & full_waiters)
1309  bpage等于根据内存节点分配内存
1311  如果非bpage则转到:fail_free_buffer
1314  rb_check_bpage(cpu_buffer, bpage)
1316  reader_page等于bpage
1317  page等于Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,* prefer the current CPU's closest node. Otherwise node must be valid and* online.
1318  如果非page则转到:fail_free_reader
1320  Actual data page 等于page_address(page)
1321  rb_init_page(Actual data page )
1323  初始化链表头
1324  初始化链表头
1326  ret等于rb_allocate_pages(cpu_buffer, nr_pages)
1327  如果ret小于0则转到:fail_free_reader
1330  ad from head 等于list_entry - get the struct for this entry*@ptr: the &struct list_head pointer.*@type: the type of the struct this is embedded in.*@member: the name of the list_head within the struct.(pages, structbuffer_page, list)
1332  write to tail 等于committed pages 等于ad from head
1334  _head_page_activate - sets up head page
1336  返回:cpu_buffer
1338  fail_free_reader :
1339  Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing* this issue out.
1341  fail_free_buffer :
1342  kfree(cpu_buffer)
1343  返回:NULL
调用者
名称描述
__ring_buffer_alloc__ring_buffer_alloc - allocate a new ring_buffer*@size: the size in bytes per cpu that is needed.*@flags: attributes to set for the ring buffer.* Currently the only flag that is available is the RB_FL_OVERWRITE* flag
trace_rb_cpu_prepareWe only allocate new buffers, never free them if the CPU goes down.* If we were to free the buffer, then the user would lose any trace that was in* the buffer.