| # Overhauled performance tracing in Chrome |
| |
| We are upgrading Chrome's support for performance tracing by replacing Chrome's implementation of |
| TRACE_EVENT macros from //base/trace_event with [Perfetto](https://perfetto.dev). Perfetto |
| introduces [trace events with typed |
| arguments](https://perfetto.dev/docs/instrumentation/track-events) to support privacy-filtered trace |
| recording and a more compact, efficient, and stable trace encoding. |
| |
| The Perfetto library itself lives in |
| [AOSP](https://android.googlesource.com/platform/external/perfetto/) and is rolled in |
| [/third_party/perfetto/](https://cs.chromium.org/chromium/src/third_party/perfetto/). |
| |
| The code in this directory connects Chrome to Perfetto's [tracing |
| SDK](https://perfetto.dev/docs/instrumentation/tracing-sdk), which implements trace event macros on |
| top of Perfetto's [tracing service](https://perfetto.dev/docs/concepts/service-model). This service |
| can be run in-process (e.g. in unit tests), as a Chrome mojo service (see //services/tracing), or as |
| a system service on Android. |
| |
| For more details, see [Perfetto's documentation](https://docs.perfetto.dev), [Typed trace events in |
| Chrome](https://docs.google.com/document/d/1f7tt4cb-JcA5bQFR1oXk60ncJPpkL02_Hi_Bc6MfTQk/edit#), and |
| [Typed trace events in |
| //base](https://docs.google.com/document/d/1UQ4Ez7B-TeowijOUuMXuoWj1amZcQ7E2abt3s4jaAEY/edit#). |
| |
| For a list of Chromium's tracing categories, see |
| [base/trace_event/builtin_categories.h](https://cs.chromium.org/chromium/src/base/trace_event/builtin_categories.h). |
