Will perfetto provide log interface for Native and Kernel Layer?

[JustinHu1983]

Currently, ProtoLog.java provides perfetto log interface (such as, d(), v(), i(), w(), e()). is there any plan to provide the same perfetto log interface for Native and Kernel Layer?

[LalitMaganti]

a) there are no plans to bring Protolog to other places.
b) the recommendation in the kernel is to use ftrace (https://perfetto.dev/docs/getting-started/ftrace) to log events and in native code to use atrace https://perfetto.dev/docs/getting-started/atrace

[JustinHu1983]

Thanks for your reply.
What's the reason no plans to bring Protolog to other places? seems perfetto better performance and less log size, why not be used to other places?

[LalitMaganti]

For the system/apps: out focus is on integrating the Perfetto SDK into the system directly instead of going through protolog. That should be even better performance and much richer feature set as well. We don't see the point in confusing things by having protolog as a stop gap solution when the native Perfetto API will exist.

For the kernel, ftrace is the default standard solution for tracing and upstream will not accept yet another tracing system and we don't want to maintain something downstream. So we think it's best to work with what we have there.

[LalitMaganti]

In the next release of Android, you should already start to see a new PerfettoTrace system API which is our focus for development moving forward. We expect this will slowly become the defacto way people talk to Perfetto from Java. This will of course also have a native counterpart. At some point, these APIs will then be exposed to the SDK and NDK.

[JustinHu1983]

So, there will be more changes on perfetto in next Android version? Completely different, or evolving on the current version features？

[LalitMaganti]

So, there will be more changes on perfetto in next Android version?

Depends what you mean on "Perfetto": the core Perfetto services and SDK have always supported a much richer feature set. They just were not hooked easily to the rest of platform code. What we are doing now is building that bridge, bringing all the new features over to the Android world.

Will it be richer than atrace: yes it's totally different in how it works.

[JustinHu1983]

uopdate on following question: What I checked is for recording log, not for trace. then, what about your suggestion?
Currently, ProtoLog.java provides perfetto log interface (such as, d(), v(), i(), w(), e()). is there any plan to provide the same perfetto log interface for Native and Kernel Layer?

[LalitMaganti]

I think I've already said everything I can above. If protolog works for you use It. Use atrace if possible otherwise. At the moment, there's nothing more I can offer.

[JustinHu1983]

OK, thanks