Display dma_fence events in a single row

[gramound]

The "dma_fence" events currently show-up 1 per row (format "%s-%s%llu-%lld", driver_name, timeline_name, context, seqno).
I'm looking at a 25s trace with over 3000 rows under "Misc Global Tracks" named like driver-timelinex-1000, driver-timelinex-1001, driver-timelinex-1002, driver-timelinex-1003, etc. Each row containing only 1 "fence" slice.

It would be nice if all the seqno of the same "driver_name,timeline_name,context" could be presented in the same row (with the seqno in the slice name).

Is this possible to do within the viewer, or does it require the Linux driver to present its events differently?

[LalitMaganti]

Yes it's possible to make the change within trace processor: you just need to change the code at https://cs.android.com/android/platform/superproject/main/+/main:external/perfetto/src/trace_processor/importers/ftrace/drm_tracker.cc;bpv=1

Patches to fix this welcome (contribution guide is available at https://perfetto.dev/docs/contributing/getting-started) but it's likely not something we will get to ourselves soon.

[gramound]

Thanks for the code link. I think I misunderstood the track name format in the issue description. According to GetFenceTimelineByContext, what I assumed to be seqno (number at the end of the track name) were actually contexts. It's probably something specific to the driver I'm investigating to increment contexts for each fence. I'll study this a bit more (might take a while).