scons_gd/scons/timings/JTimer/TimeSCons-run.py
2022-10-15 16:06:26 +02:00

65 lines
2.5 KiB
Python

#
# __COPYRIGHT__
#
# Permission is hereby granted, free of charge, to any person obtaining
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# without limitation the rights to use, copy, modify, merge, publish,
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# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
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# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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"""
This configuration is for timing how we evaluate long chains of
dependencies, specifically when -j is used.
We set up a chain of $TARGET_COUNT targets that get built from a
Python function action with no source files (equivalent to "echo junk >
$TARGET"). Each target explicitly depends on the next target in turn,
so the Taskmaster will do a deep walk of the dependency graph.
This test case was contributed by Kevin Massey. Prior to revision 1468,
we had a serious O(N^2) problem in the Taskmaster when handling long
dependency chains like this. That was fixed by adding reference counts
to the Taskmaster so it could be smarter about not re-evaluating Nodes.
"""
import TestSCons
# Full-build time of just under 10 seconds on ubuntu-timings slave,
# as determined by bin/calibrate.py on 9 December 2009:
#
# run 1: 3.211: TARGET_COUNT=50
# run 2: 11.920: TARGET_COUNT=155
# run 3: 9.182: TARGET_COUNT=130
# run 4: 10.185: TARGET_COUNT=141
# run 5: 9.945: TARGET_COUNT=138
# run 6: 10.035: TARGET_COUNT=138
# run 7: 9.898: TARGET_COUNT=137
# run 8: 9.840: TARGET_COUNT=137
# run 9: 10.054: TARGET_COUNT=137
# run 10: 9.747: TARGET_COUNT=136
# run 11: 9.778: TARGET_COUNT=136
# run 12: 9.743: TARGET_COUNT=136
#
# The fact that this varies so much suggests that it's pretty
# non-deterministic, which makes sense for a test involving -j.
test = TestSCons.TimeSCons(variables={'TARGET_COUNT':136})
test.main()
test.pass_test()