Project:Portage/Profiling

Collecting profiles

To collect a pstats profile in outfile:

user $python -m cProfile -o outfile /usr/bin/emerge <args>

Examining profiles

Assuming the profile was collected above in outfile, examine it:

user $python

>>> import pstats
>>> p = pstats.Stats('outfile')
>>> p.print_stats()

Check out the https://docs.python.org/3/library/profile.html for more details.

Example

This example is from:

user $python -m cProfile -o portage.cprof /usr/bin/emerge -pe @world

user $python

>>> import pstats
>>> p = pstats.Stats('portage.cprof')
>>> p.sort_stats('time').print_stats(20)
Thu Feb 11 05:41:32 2021    portage.cprof

         34119136 function calls (32523207 primitive calls) in 94.908 seconds

   Ordered by: internal time
   List reduced from 3287 to 20 due to restriction <20>

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
   386794    6.291    0.000    8.858    0.000 /usr/lib/python3.9/site-packages/portage/util/digraph.py:163(child_nodes)
1515214/2431    5.836    0.000   17.283    0.007 /usr/lib/python3.9/site-packages/_emerge/depgraph.py:7838(gather_deps)
119338/96762    5.014    0.000   15.934    0.000 /usr/lib/python3.9/site-packages/portage/dep/__init__.py:1243(__init__)
     1865    4.142    0.002    8.434    0.005 /usr/lib/python3.9/site-packages/portage/package/ebuild/config.py:2250(regenerate)
   431910    3.566    0.000    3.566    0.000 {method 'match' of 're.Pattern' objects}
   132060    3.070    0.000    5.127    0.000 /usr/lib/python3.9/site-packages/portage/versions.py:363(__init__)
     3726    2.841    0.001   18.456    0.005 /usr/lib/python3.9/site-packages/portage/package/ebuild/config.py:1432(setcpv)
  3140510    1.928    0.000    1.928    0.000 /usr/lib/python3.9/site-packages/_emerge/Task.py:23(__hash__)
  2685578    1.699    0.000    1.875    0.000 {method 'add' of 'set' objects}
    22576    1.650    0.000    2.502    0.000 /usr/lib/python3.9/site-packages/portage/dep/__init__.py:873(__init__)
  1564306    1.559    0.000    1.559    0.000 /usr/lib/python3.9/site-packages/_emerge/DepPrioritySatisfiedRange.py:43(_ignore_runtime_post)
   444155    1.429    0.000    1.429    0.000 {method 'split' of 'str' objects}
     3920    1.403    0.000    2.001    0.001 /usr/lib/python3.9/site-packages/_emerge/resolver/output.py:142(map_to_use_expand)
   141972    1.148    0.000    1.801    0.000 /usr/lib/python3.9/site-packages/portage/package/ebuild/config.py:2637(_getitem)
    13373    1.126    0.000   14.950    0.001 /usr/lib/python3.9/site-packages/portage/dep/__init__.py:402(_use_reduce_cached)
     2823    1.022    0.000    1.412    0.001 /usr/lib/python3.9/site-packages/portage/package/ebuild/_config/LicenseManager.py:161(getMissingLicenses)
  1597513    1.006    0.000    1.150    0.000 {method 'get' of 'dict' objects}
829430/823631    0.934    0.000    1.514    0.000 {built-in method builtins.getattr}
  1573917    0.886    0.000    0.886    0.000 {method 'group' of 're.Match' objects}
    63283    0.864    0.000    1.593    0.000 /usr/lib/python3.9/site-packages/portage/dep/__init__.py:2148(match_from_list)


<pstats.Stats object at 0x7fa392065c10>