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android / platform / external / perfetto.git / refs/tags/android-9.0.0_r37
taga07e628804a3e9f2659ac01889d0a12ef54476fb
taggerThe Android Open Source Project <initial-contribution@android.com>Mon May 06 14:11:50 2019 -0700
objectc5e18407c277ca75b854b4416c70d23dc2c6a90e 
Android 9.0.0 Release 37 (PQ3A.190505.002)
commitc5e18407c277ca75b854b4416c70d23dc2c6a90e[log] [tgz]
authorHector Dearman <hjd@google.com>Wed Jun 20 10:57:06 2018 +0100
committerPrimiano Tucci <primiano@google.com>Wed Jun 20 15:14:06 2018 +0100
tree4c03e4372ba0c8cc83880b65bb608d16442753e3
parent05cd4b895e5d78ef82448cb9bf71fba6b1ad48ae [diff]
traced_probes: Fix clock bug

There was a bug when parsing the list of available clocks from
/d/tracing/trace_clock.

The contents of /d/tracing/trace_clock looks like:
uptime perf mono mono_raw boot\n
We acidentally included the newline in the name of the final clock when
reading. This means (if boot is unfortunate enough to be the last clock
listed) we fail to set the boot clock (since "boot" != "boot\n").

Fix the parsing of trace_clock to discount the newline.

Bug: 110356412
Change-Id: I5160637efec69844fe75f8e705d02a7c486ae990
Merged-In: I5160637efec69844fe75f8e705d02a7c486ae990
(cherry picked from commit 22dac14815a58d00ea87a0013bb638c703843f11)
2 files changed
tree: 4c03e4372ba0c8cc83880b65bb608d16442753e3
  1. build_overrides/
  2. buildtools/
  3. debian/
  4. docs/
  5. gn/
  6. include/
  7. infra/
  8. protos/
  9. src/
  10. test/
  11. tools/
  12. .clang-format
  13. .gitignore
  14. .gn
  15. .travis.yml
  16. Android.bp
  17. Android.bp.extras
  18. BUILD.gn
  19. codereview.settings
  20. MODULE_LICENSE_APACHE2
  21. NOTICE
  22. OWNERS
  23. perfetto.rc
  24. PRESUBMIT.py
  25. README.chromium
  26. README.md
README.md

Perfetto - Performance instrumentation and tracing

Perfetto is an open-source project for performance instrumentation and tracing of Linux/Android/Chrome platforms and user-space apps.
It consists of:

A portable, high efficiency, user-space tracing library
designed for tracing of multi-process systems, based on zero-alloc zero-copy zero-syscall (on fast-paths) writing of protobufs over shared memory.

OS-wide Linux/Android probes for platform debugging

  • Kernel tracing: a daemon that converts Kernel Ftrace events into API-stable protobufs, on device, with low overhead.
  • I/O tracing
  • Many new probes coming soon: heap profiling, perf sampling, syscall tracing.

Web-based frontend
A UI for inspection and analysis of traces (coming soon).

Batch processing of traces
A python / C++ (TBD) library for trace-based metrics (coming soon).

Perfetto Stack

Goals

Perfetto is building the next-gen unified tracing ecosystem for:

  • Android platform tracing (Systrace)
  • Chrome platform tracing (chrome://tracing)
  • App-defined user-space tracing (including support for non-Android apps).

The goal is to create an open, portable and developer friendly tracing ecosystem for app and platform performance debugging.

Key features

Designed for production
Perfetto's tracing library and daemons are designed for use in production. Privilege isolation is a key design goal:

  • The interface for writing trace events are decoupled from the interface for read-back and control and can be subjected to different ACLs.
  • Despite being based on shared memory, Perfetto is designed to prevent cross-talk between data sources, even in case of arbitrary code execution (memory is shared point-to-point, memory is never shared between processes).
  • Perfetto daemons are designed following to the principle of least privilege, in order to allow strong sandboxing (via SELinux on Android).

See docs/security-model.md for more details.

Long traces
Pefetto aims at supporting hours-long / O(100GB) traces, both in terms of recording backend and UI frontend.

Interoperability
Perfetto traces (output) and configuration (input) consists of protobuf messages, in order to allow interoperability with several languages.

See docs/trace-format.md for more details.

Composability
As Perfetto is designed both for OS-level tracing and app-level tracing, its design allows to compose several instances of the Perfetto tracing library, allowing to nest multiple layers of tracing and drive then with the same frontend. This allows powerful blending of app-specific and OS-wide trace events. See docs/multi-layer-tracing.md for more details.

Portability
The only dependencies of Perfetto's tracing libraries are C++11 and Protobuf lite (plus google-test, google-benchmark, libprotobuf-full for testing).

Extensibility
Perfetto allows third parties to defined their own protobufs for:

Allowing apps to define their own strongly-typed input and output schema. See docs/trace-format.md for more details.

Docs