register_trace_##name宏中node
tracepoint_probe_register在這個函數中在同一個cp上能夠掛多個處理函數，函數
查看函數：trace_block_rq_issue中定義了這個tracepoint以及ｔｒａｃｅｐｏｉｎｔ的鉤子函數code
tracepoint中給你輸入了trace_block_rq_issue(q, rq);其中ｑ是request_queue，ｒｑ是struct request，這兩個東西是ｔｒａｃｅｐｏｉｎｔ提供給你的，全部的函數都可以獲得，這個函數的執行的流程是啥樣子的啊，鉤子函數中必定是要有void函數的，各路ｆｔｒａｃｅ啥的都註冊了本身的函數，包括ｐｅｒｆ也是在函數中註冊了本身的函數，看下ｆｔｒａｃｅ註冊的什麼函數呢，ftrace中確定是註冊了本身的特定的函數orm
kernel/trace/trace_events.c中有許多的鉤子函數blog
ftrace_enable_fopsget
ftrace_event_format_fopsit
__ftrace_event_enable_disable鉤子
使用牛逼的ｓｙｓｔｅｍｔａｐ能夠垂手可得地獲得函數中的鉤子是啥：call->class->reg(call, TRACE_REG_UNREGISTER, file);event
獲得鉤子的地址是：trace_event_regast
而後鉤子函數是啥子咧，發現是是函數 trace_event_raw_event_block_rq_issue
這個函數是咋生成的呢？
都是在頭文件中生成的
./include/trace/events/f2fs.h
DECLARE_EVENT_CLASS在這個宏中會擴展函數trace_event_raw_event_block_rq_issue函數
以f2fs的ｄｅｃｌａｒｅ_event_class函數中
122 DECLARE_EVENT_CLASS(f2fs__inode,
123
124 TP_PROTO(struct inode *inode),
125
126 TP_ARGS(inode),
127
128 TP_STRUCT__entry(
129 __field(dev_t, dev)
130 __field(ino_t, ino)
131 __field(ino_t, pino)
132 __field(umode_t, mode)
133 __field(loff_t, size)
134 __field(unsigned int, nlink)
135 __field(blkcnt_t, blocks)
136 __field(__u8, advise)
137 ),
138
139 TP_fast_assign(
140 __entry->dev = inode->i_sb->s_dev;
141 __entry->ino = inode->i_ino;
142 __entry->pino = F2FS_I(inode)->i_pino;
143 __entry->mode = inode->i_mode;
144 __entry->nlink = inode->i_nlink;
145 __entry->size = inode->i_size;
146 __entry->blocks = inode->i_blocks;
147 __entry->advise = F2FS_I(inode)->i_advise;
148 ),
149
150 TP_printk("dev = (%d,%d), ino = %lu, pino = %lu, i_mode = 0x%hx, "
151 "i_size = %lld, i_nlink = %u, i_blocks = %llu, i_advise = 0x%x",
152 show_dev_ino(__entry),
153 (unsigned long)__entry->pino,
154 __entry->mode,
155 __entry->size,
156 (unsigned int)__entry->nlink,
157 (unsigned long long)__entry->blocks,
158 (unsigned char)__entry->advise)
159 );
函數中：
./include/trace/trace_events.h
664 static notrace void \
665 trace_event_raw_event_##call(void *__data, proto) \
666 { \
667 struct trace_event_file *trace_file = __data; \
668 struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
669 struct trace_event_buffer fbuffer; \
670 struct trace_event_raw_##call *entry; \
671 int __data_size; \
672 \
673 if (trace_trigger_soft_disabled(trace_file)) \
674 return; \
675 \
676 __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
677 \
678 entry = trace_event_buffer_reserve(&fbuffer, trace_file, \
679 sizeof(*entry) + __data_size); \
680 \
681 if (!entry) \
682 return; \
683 \
684 tstruct \
685 \
686 { assign; } \
687 \
688 trace_event_buffer_commit(&fbuffer); \
689 }
按說，ｆｔｒａｃｅ的ｐｒｉｎｔｋ部分
ｐｅｒｆ註冊的函數是perf_trace_##call函數，include/trace/perf.h文件