commit | 15314ea99f307675df27fe261e90ce88d0295362 | [log] [tgz] |
---|---|---|
author | Isabelle Taylor <taylori@google.com> | Wed Sep 19 11:35:19 2018 +0100 |
committer | Isabelle Taylor <taylori@google.com> | Wed Sep 19 11:35:19 2018 +0100 |
tree | a1a4f40005020256a587096ccbc87ebf69e47f08 | |
parent | c42c66b2dd053527068cab84c7af44df08b00475 [diff] |
trace_processor: Flatten CPU freq storage and remove cycles In order to join the cpu freq information quickly with the sched table the cpu freq events need to be in timestamp order, rather than stored per cpu. A side effect of that is that we can't quickly compute cycles the way that we were doing before, but that's OK because we can compute cycles when we span join with the sched table. The counters table is not optimised. We let SQLite do the filtering and ordering for now. Since the counters are no longer stored by cpu, duration can not be computed on the fly. Instead a stage is added to sched_tracker (rename pending) similar to the sched slices that waits for the next event on the same cpu before outputting the prev event with it's duration. Change-Id: I27da5366aae6bd4cf6a7d30b1e248b938f50b965
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
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 is building the next-gen unified tracing ecosystem for:
The goal is to create an open, portable and developer friendly tracing ecosystem for app and platform performance debugging.
Designed for production
Perfetto's tracing library and daemons are designed for use in production. Privilege isolation is a key design goal:
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.