Dear community, [Goal] I am trying to understand more about tracing. In one of my experiments, I decided to try to write my own trace.dat file (with some dummy entries). To do that, I am following the documentation for a "version-7 .dat" provided in https://github.com/rostedt/trace-cmd/blob/master/Documentation/trace-cmd/trace-cmd.dat.v7.5.txt , and trying to looking at the code of libtraceevent, trace-cmd and kernelshark. I use kernelshark to be sure I am writing a good trace. [Context] I managed to write a complete header (I double-checked checking in strategical points in trace-cmd, kernelshark and libtraceevent code). In this header, I have three sections: - Section 0, with options 16 (header_infos), option 8 (in which I stated to have a single CPU), and option 3. The latter states that I have a cpu whose data starts at offset 4096 of the trace. - Section 16: in which I transfers the information of `header_page` and `header_event` files. - Section 3: the flyrecord section, whose header is followed by a padding to be one-page aligned. After the padding, there should be the CPU datas. Yet another check of the header's correctness are outputs of commands `trace-cmd dump --flyrecord -i mytrace.dat` and `trace-cmd dump --summary -i ../mytrace_v7.dat`. [Problem] The problems occur there. I don't manage to get the format of flyrecords. I understood that timestamps need to follow the structure of ringbuffers (those expressed in `header_event` file), so 5 bits for the type_len, 27 for the time_delta, and an u32 array[]. But, kernelshark entries contains also: timestamp, CPUs, PID, EVENT, TASK, LATENCY and "INFO". Through flybuffer schema, I can only provide TIMESTAMP divided by CPUs, but where do I take other fields? In addition to this, I didn't understand how I can provide multiple entries. Thanks for you possible help, Matteo
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