Re: perf: store and retrieve trace event names in the perf.data file

Arjan van de Ven
2009-08-09T23:01:28Z

Frederic Weisbecker wrote:
> On Sun, Aug 09, 2009 at 02:49:23PM -0700, Arjan van de Ven wrote:
>> In order to be able to use trace events, a key aspect is the "type" field;
>> this is the id of the event that you recorded, as stored in the /sys/kernel/debug/events/*/*/id file.
>> What is currently missing is a way to map the id number (which is not abi stable)
>> to the event that was recorded.
>
>
>
> We already have that.
> See tools/perf/util/parse-events.c: char *tracepoint_id_to_name(u64 id)

sadly... we don't.

You do it *on the same boot and machine* as you created the perf.data file.
You don't have it when you reboot into a new kernel, or move the perf.data file
to a new machine........

Which is to be honest a very common usecase.