On Mon, 4 Mar 2024 20:35:16 -0500 Steven Rostedt <rost...@goodmis.org> wrote:
> > BUILD_BUG_ON(TRACING_MARK_MAX_SIZE + sizeof(meta data stuff...) > > > TRACE_SEQ_SIZE); > > That's not the meta size I'm worried about. The sizeof(meta data) is the > raw event binary data, which is not related to the size of the event output. > > # cd /sys/kernel/tracing > # echo hello > trace_marker > # cat trace > [..] > <...>-999 [001] ..... 2296.140373: tracing_mark_write: hello > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > This is the meta data that is added to trace_seq That said, the meta data is most likely not going to be more than 128 bytes (it shouldn't be more than 80). I could do as you suggest and create a separate TRACE_MARKER_SIZE and just make sure that it's less than TRACE_SEQ_BUFFER_SIZE (as that's the size of the content) by 128 bytes. /* Added meta data should not be more than 128 bytes */ BUILD_BUG_ON((TRACE_MARKER_MAX_SIZE + 128) > TRACE_SEQ_BUFFER_SIZE); -- Steve
