Hi, We are currently working on the CTF2 specification [1] at EfficiOS, and there is a user metric we would need to help us with a design decision with respect to enumerations. This is where we would need community input.
The usage metrics in question are with respect to LTTng-UST enumeration types (TRACEPOINT_ENUM) [2] used by tracepoint events within instrumented applications. A tracepoint enumeration can be used by many events. What we are looking for is to get an idea of the common use, and extreme cases as well. Ideally, what we would need is: - For each enumeration within your application instrumentation (TRACEPOINT_ENUM), how many events refer to each enumeration ? (average, mode, and maximum) - For each TRACEPOINT_ENUM, how many labels do they possess ? (sum number of ctf_enum_value/ctf_enum_range/ctf_enum_auto entries) (average, mode, and maximum) - For each TRACEPOINT_ENUM, for each label, what is the string length ? (average, mode, and maximum) Based on this information, we can estimate the data overhead generated by repeating enumeration labels in the LTTng-UST metadata. We need to decide whether we allow references to a single enumeration description when it is used by many events, or if we require repeatedly serializing the entire enumeration description for each event field using the enumeration. Thanks, Mathieu [1] https://lists.lttng.org/pipermail/lttng-dev/2020-November/029777.html [2] https://lttng.org/man/3/lttng-ust/v2.12/#doc-tracepoint-enum -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
