perfetto UI can see streaming data directly from linux target?

[deco-dev]

Hello.

Environment
Host: Windows amd64(Chrome)
Target: Linux arm64(Ubuntu)
Interface: USB host - device or USB RNDIS.

I want to see profiling data to realtime on perfetto UI. But perfetto UI only supports ADB device.
But my target board is operating Linux arm64(Ununtu). So I can not use adbd.
I tried to this.
In host PC I runs trace_processor_shell -D. and enter perfetto UI.
In target board I runs traced, traced_probes and perfetto -txt -c config.json -o -.
But the trace data just is printed in STDOUT.

Please help me.

[LalitMaganti]

There is no "easy & out of the box" support for streaming data over the network/USB from non-Android devices with Perfetto. If you are willing to get your hands dirty, you might want to checkout traced_relay [1] which is designed for forwarding tracing data across VMs but hypothetically should also be able to forward tracing data over the network across machines. However, note that this is completely untested and we cannot provide support for this. You are on your own to figure out this stuff if you go this route.

Also just want to clarify that when collecting traces on Android, the data on the UI is not displayed "relatime" like you seem to suggest. it's just streamed to the host where it's stored in a file/in memory and then when tracing is completed the file is parsed as a whole and then opened.

In host PC I runs trace_processor_shell -D. and enter perfetto UI.

No idea why running trace_processor_shell here is mentioned, it's not relevant at all really.

But the trace data just is printed in STDOUT.

Which makes sense because you have specified -o - which means "write the trace to the command line".

[1]

perfetto/src/traced_relay/relay_service_main.cc

Line 31 in 2cb2b19

Relays trace data to a remote tracing service. Cannot run alongside the "traced"

[deco-dev]

Then is it difficult to see profiling in realtime of Android devices using perfetto UI in host PC?

[LalitMaganti]

There's no real time profiling visualization available on android.

[LalitMaganti]

It's one of those features which sounds very cool but in practice it's not a huge deal. It's also immensely complex to actually implement because trace information is written out of order and is heterogeneous. Making all the visualization work correctly is so hard that it's basically not worth it.

[deco-dev]

OK. I understood.

[deco-dev]

Other profiling Tools (like ARM Development Sudio or Qualcomm Profiler) support live profiling(realtime).
So I tried to it using perfetto ui.

[LalitMaganti]

Sure but Perfetto supports many more event types and heterogeneous data which those tools do not bother dealing with. If those tools work better for you, then you should feel free to use them :)

[deco-dev]

I have one more question.
perfetto supports hw_perf_event like cache-misses, cpu-cycles? I tested it, it did not work well.

My goal is hw perf event(pmu) and trace data(like ftrace, proc/, sys stat) show visualization at same time on realtime.

[deco-dev]

Right. I am on linux. I used traced and traced_probes to background mode and I used perfetto.

[LalitMaganti]

You also require traced_perf to be running for perf sampling. It's a separate Daemon if you are building from sources or you can just get it all in one if you run tracebox.

[deco-dev]

ok got it. If I get trace data to use tracebox, then I can see the data on perfetto UI?

[LalitMaganti]

It should work from everything I know :)

[deco-dev]

It worked well! Thank you!