JZTXT

Linux tracepoint使用和理解

发布时间 2023-12-15 11:51:13作者: 梦过无声

参考:如何使用 TRACE_EVENT() 宏来创建跟踪点

1.如何查看tracepoint

/sys/kernel/debug/tracing/events/

通过perf list tracepoint查看

2. tracepoint理解

因此tracepoint方式如下:

#undef TRACE_SYSTEM
#define TRACE_SYSTEM xhr_test

#if !defined(_TRACE_TE_TEST_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_TE_TEST_H

#include <linux/tracepoint.h>

TRACE_EVENT(te_test,  // 定义函数trace_te_test
    TP_PROTO(int num), // 函数接收参数 int 类型
    TP_ARGS(num),
    TP_STRUCT__entry(
        __field(int, output)  // 字段名
        __field(int, count)   // 字段名
    ),
    TP_fast_assign(
        __entry->count++;
        __entry->output = num; // output 等于传入的参数 num
    ),
    TP_printk("count=%d output=%d",
        __entry->count, __entry->output)
);

#endif /* _TRACE_TE_TEST_H */
    
/* This part must be outside protection */
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH . //定义路径,找不到你就写绝对路径
#define TRACE_INCLUDE_FILE trace_event //定义文件 trace_event.h

#include <trace/define_trace.h>

因此,只要调用 trace_te_test(int num)即可

3.快速查找tracepoint

grep -rn TRACE_EVENT(name, ...)