commit | 2755dd2f221685586f31ee0f289caf952850a874 | [log] [tgz] |
---|---|---|
author | Primiano Tucci <primiano@google.com> | Wed May 02 11:30:12 2018 +0100 |
committer | Primiano Tucci <primiano@google.com> | Fri May 04 20:20:10 2018 +0100 |
tree | 74fad7fd9f5fdb22bc39b456652cbaee09a77153 | |
parent | 18bee92239d27fe178ab7fe520de237a17e0b264 [diff] |
ps_tree: No scan on startup by default, make thread names optional There can be over 1500 threads in total and dumping all of them at startup causes: 1) Too much use of the trace buffer. 2) Because of 1, the buffer is more likely to wrap, and we are more likely to lose the whole TracePacket with the ps tree. However, once the initial dump is made, the data source is convinced that we recorded all those threads and will stop emitting them later on. As such we get ironically less data compared to the on-deman only case. This CL: - Makes the dump on startup optional. - Makes dumping thread names optional (they are redundant given that they show up already in sched_switch events) This CL diable the scan on startup Bug: 78106582 Change-Id: I12e9c3e32f4af9e0dd5bb4d67be88706bb47b40e Merged-In: I12e9c3e32f4af9e0dd5bb4d67be88706bb47b40e (cherry picked from commit e8d7595f35ff1ad68581164d18d762afb3c03383)
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.