trace_net_dev_xmit 定义在何处？

net/core/dev.c中有：

rc = ops->ndo_start_xmit(skb, dev);
trace_net_dev_xmit(skb, rc);

在 include/trace/events/net.h中有
TRACE_EVENT(net_dev_xmit,。。。


在 include/linux/tracepoint.h中有
#define TRACE_EVENT(name, proto, args, struct, assign, print)    \
    DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
    
#define DECLARE_TRACE(name, proto, args)                \
        __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), 1,    \
                PARAMS(void *__data, proto),        \
                PARAMS(__data, args))
                    
#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args)    \
    static inline void trace_##name(proto)                \
    { }                                \
    static inline int                        \
    register_trace_##name(void (*probe)(data_proto),        \
                  void *data)                \
    {                                \
        return -ENOSYS;                        \
    }                                \
    static inline int                        \
    unregister_trace_##name(void (*probe)(data_proto),        \
                void *data)                \
    {                                \
        return -ENOSYS;                        \
    }                                \
    static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
    {                                \
    }

好家伙，trace_##name 终于现身了。