80 lines
2.2 KiB
ReStructuredText
80 lines
2.2 KiB
ReStructuredText
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Profiling the Tezos node
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========================
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Memory profiling the OCaml heap
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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- Install an OCaml switch with the statmemprof patch:
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``4.04.2+statistical-memprof`` or ``4.06.0+statistical-memprof``
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- Install ``statmemprof-emacs``.
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- Enable loading statmemprof into the node.
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Add the ``statmemprof-emacs`` package as a dependency to the main package, and add
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``let () = Statmemprof_emacs.start 1E-4 30 5`` to the ``node_main.ml`` file.
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Arguments:
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- ``sampling_rate`` is the sampling rate of the profiler. Good value: ``1e-4``.
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- ``callstack_size`` is the size of the fragment of the call stack which is captured for each sampled allocation.
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- ``min_sample_print`` is the minimum number of samples under which the location of an allocation is not displayed.
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- Load sturgeon into emacs, by adding this to your ``.emacs``:
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::
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(let ((opam-share (ignore-errors (car (process-lines "opam" "config" "var" "share")))))
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(when (and opam-share (file-directory-p opam-share))
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(add-to-list 'load-path (expand-file-name "emacs/site-lisp" opam-share))))
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(require 'sturgeon)
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- Launch the node then connect to it with sturgeon.
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If the process is launched with pid ``1234`` then
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::
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M-x sturgeon-connect
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tezos-nodememprof.1234.sturgeon
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(tab-completion works for finding the socket name)
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Memory profiling the C heap
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~~~~~~~~~~~~~~~~~~~~~~~~~~~
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- Install ``valgrind`` and ``massif-visualizer``
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::
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valgrind --tool=massif tezos-node run ...
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- Stop with `Ctrl-C` then display with
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::
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massif-visualizer massif.out.pid
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Performance profiling
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~~~~~~~~~~~~~~~~~~~~~
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- Install perf (The ``linux-perf`` package for debian.
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If the package does not exist for your current kernel, a previous
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version can be used. substitute the ``perf`` command to ``perf_4.9``
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if your kernel is 4.9).
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- Run the node, find the pid.
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- Attach perf with ``perf record -p pid --call-stack dwarf``.
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Then stop capturing with ``Ctrl-C``. This can represent a lot of
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data. Don't do that for too long. If this is too much you can remove
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the ``--call-stack dwarf`` to get something more manageable, but
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interpreting the information can be harder.
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- display the result with ``perf report``
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