Add metadata to events in progress, new `dynamo` event
Summary:
X-link: https://github.com/pytorch/pytorch/pull/138477
This diff does a few things:
## Add metadata to events in progress
Adds the ability to add extra metadata to Chromium Events via `add_event_data`.
Metadata can only be added to chromium events that have started, but not ended (so, in progress events)
- When you add the data, the metadata is appended to the metadata when you call log_event_end().
- The metadata appears in chromium events in tlparse. It also gets logged to scuba.
## New `dynamo` chromium event
We add a new `dynamo` chromium event to the top of the stack, where we collect various metadata found in dynamo_compile. So the new order of events goes:
```
__start__
-> dynamo (dynamo compile metrics)
-> entire_frame_compile (compile.inner)
-> backend_compile (i.e. aotdispatch)
-> create_aot_dispatch_function
-> inductor_compile
-> ...
```
BackwardCompilationMetrics doesn't have any dynamo specific information (as it's mostly inductor timings). So we don't include that here.
*FAQ: Why can't we use `entire_frame_compile` as the event?*
This is mostly due to backward compatibility with `dynamo_compile`. `dynamo_compile` collects CompilationMetrics outside of `compile.compile_inner`, and uses `dynamo_timed` to grab timings from phases of the compiler, including `entire_frame_compile`. So we don't have a CompilationMetric object until after an `entire_frame_compile` event ends! Separately, `dynamo` as a name for all of dynamo compile is more descriptive than `entire_frame_compile`, imo.
## Log metadata as separate columns
(Meta only): Separately, this also changes the `metadata` column in PT2 Compile Events. Instead of logging a single metadata column in JSON, it separates the JSON into separate columns. This is much better for data analysis. Now that this table is more mature, I think logging keys to separate columns is a better system.
ghstack-source-id: 249373269
Reviewed By: aorenste
Differential Revision: D64696287
fbshipit-source-id: 441f57e2d1c0210e81c06eb86d4482e95bed4971
