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fuchsia/fuchsia/52d7eb2d66631c8/./src/performance/memory/profile
tree: 83d17225ed32735a13a3aa4c724f9408e4268d65
  1. example/
  2. meta/
  3. BUILD.gn
  4. fxt_to_pprof.cc
  5. fxt_to_pprof.h
  6. fxt_to_pprof_main.cc
  7. fxt_to_pprof_test.cc
  8. memory_layout.cc
  9. memory_layout.h
  10. memory_trace.cc
  11. memory_trace_test.cc
  12. profile_memory.sh
  13. README.md
  14. record_container.h
  15. stack_compression.cc
  16. stack_compression.h
  17. stack_compression_test.cc
  18. test_record_container.cc
  19. test_record_container.h
  20. trace_constants.h
src/performance/memory/profile/README.md

Memory allocation and deallocation trace

This experimental tool intercepts allocations and deallocation and logs the events to the fuchsia tracing system with the category memory_trace.

Prerequisite

  • Add the following option to fx set: --with-host //src/performance/memory/profile:fxt_to_pprof --with-base //bundles:tools
  • Ensure that pprof and gzip binaries are in the environment path.

Getting started

  • Dynamically link the component with libmemory_trace.so (//src/performance/memory/profile:memory_trace).
  • [Rust only] Add configs = [ "//src/performance/memory/profile:no-as-needed" ] to the rustc_binary.
  • Route fuchsia.tracing.provider.Registry to the component.
  • Ensure your component registers a trace provider.

The dynamic library registers hooks the Fuchsia default allocator for c and rust programs.

The memory profile collection can be started and stopped with ffx tool, however an helper script is provided to automate the trace post processing.

Know that trace collection modes commes with limitations:

  • streaming can drop samples when the tracing rate is high.
  • oneshot stops collecting without user feedback in ffx when the buffer is full.
  • circular is not usable because the first records of the memory profile are lost. Unfortunately they contains data required for symbolization.

bash src/performance/memory/profile/profile_memory.sh

This tool does the following:

  1. Starts the trace collection: ffx trace start --buffering-mode circular --categories memory_profile
  2. Converts the fxt trace to pprof protocol buffer format with //src/performance/memory/profile:memory_trace
  3. Gzip the resulting protobuf
  4. Convert the build-id directory to a format supported by pprof
  5. Starts pprof and upload the profile to a server

Try it

  • Add the following option to fx set: --with //src/performance/memory/profile/example
  • Start collection: bash src/performance/memory/profile/profile_memory.sh
  • Start the binary: ffx component create /core/session-manager/session:hello-memory-profiler fuchsia-pkg://fuchsia.com/hello-memory-profiler#meta/hello-memory-profiler.cm ffx component start /core/session-manager/session:hello-memory-profiler

Development

Run the test with fx set: --with //src/performance/memory/profile:tests

Then:

fx test //src/performance/memory/profile