Have a way to filter by process / command for perf.data-converted profiles

[nolanmar511]

The profile.proto data format does not have a specific way to note which process a sample came from. However, perf.data files tend to include samples from multiple processes.

When using pprof on perf.data files, it should be possible to determine which process a sample is from, and this should be displayed to the user.

[aalexand]

The profile.proto data format does not have a specific way to note which process a sample came from.

The easiest would be using tags. The perf_data_converter currently has a way to add process ID tags as part of conversion, I believe. We should make it so it also knows how to add command name tags, and then configure the converter run to add those tags. This will allow using tag filtering to filter by a specific process.

[aalexand]

@lannadorai Maybe you are the right owner for this after all. I think what we want here is make the perf data file conversion produce the process name / command label so that pprof can be used to filter by that tag.

[aalexand]

https://github.com/google/perf_data_converter/blob/10d8bde947030abd2d0d9d794960210c4945a4c9/src/perf_data_converter.h#L42 is the label I mean.

[lannadorai]

@aalexand Please assign this issue to the right person.