The +{macro-name}()+ utility macro was developed to make user space

tracing super simple, albeit with notable disadvantages compared to

custom, full-fledged tracepoint providers:

  * All generated events have the same provider/event names.

  * There's no static type checking.

  * The only event field with user data you actually get, named `msg`,

    is a string potentially containing the values you passed to the

    macro using your own format. This also means that you cannot use

    filtering using a custom expression at run time because there are no

    isolated fields.

  * Since +{macro-name}()+ uses C standard library's man:vasprintf(3)

    function in the background to format the strings at run time, its

    expected performance is lower than using custom tracepoint providers

    with typed fields, which do not require a conversion to a string.

  * Generally, a string containing the textual representation of the

    user data fields is not as compact as binary fields in the

    resulting trace.

Thus, +{macro-name}()+ is useful for quick prototyping and debugging, but

should not be considered for any permanent/serious application

instrumentation.

See man:lttng-ust(3) to learn more about custom tracepoint providers.