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[Perl/perl5] b07e9b: TAP::Harness: Move timer initialization

From:
Karl Williamson via perl5-changes
Date:
October 18, 2020 12:43
Subject:
[Perl/perl5] b07e9b: TAP::Harness: Move timer initialization
Message ID:
Perl/perl5/push/refs/heads/smoke-me/khw-regexec/6971bb-0ee435@github.com
  Branch: refs/heads/smoke-me/khw-regexec
  Home:   https://github.com/Perl/perl5
  Commit: b07e9be6e5942e92e9b7bc3cf96377df654234b1
      https://github.com/Perl/perl5/commit/b07e9be6e5942e92e9b7bc3cf96377df654234b1
  Author: Karl Williamson <khw@cpan.org>
  Date:   2020-10-18 (Sun, 18 Oct 2020)

  Changed paths:
    M cpan/Test-Harness/lib/App/Prove.pm
    M cpan/Test-Harness/lib/App/Prove/State.pm
    M cpan/Test-Harness/lib/App/Prove/State/Result.pm
    M cpan/Test-Harness/lib/App/Prove/State/Result/Test.pm
    M cpan/Test-Harness/lib/TAP/Base.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Base.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Color.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Console.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Console/ParallelSession.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Console/Session.pm
    M cpan/Test-Harness/lib/TAP/Formatter/File.pm
    M cpan/Test-Harness/lib/TAP/Formatter/File/Session.pm
    M cpan/Test-Harness/lib/TAP/Formatter/Session.pm
    M cpan/Test-Harness/lib/TAP/Harness.pm
    M cpan/Test-Harness/lib/TAP/Harness/Env.pm
    M cpan/Test-Harness/lib/TAP/Object.pm
    M cpan/Test-Harness/lib/TAP/Parser.pm
    M cpan/Test-Harness/lib/TAP/Parser/Aggregator.pm
    M cpan/Test-Harness/lib/TAP/Parser/Grammar.pm
    M cpan/Test-Harness/lib/TAP/Parser/Iterator.pm
    M cpan/Test-Harness/lib/TAP/Parser/Iterator/Array.pm
    M cpan/Test-Harness/lib/TAP/Parser/Iterator/Process.pm
    M cpan/Test-Harness/lib/TAP/Parser/Iterator/Stream.pm
    M cpan/Test-Harness/lib/TAP/Parser/IteratorFactory.pm
    M cpan/Test-Harness/lib/TAP/Parser/Multiplexer.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Bailout.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Comment.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Plan.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Pragma.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Test.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Unknown.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/Version.pm
    M cpan/Test-Harness/lib/TAP/Parser/Result/YAML.pm
    M cpan/Test-Harness/lib/TAP/Parser/ResultFactory.pm
    M cpan/Test-Harness/lib/TAP/Parser/Scheduler.pm
    M cpan/Test-Harness/lib/TAP/Parser/Scheduler/Job.pm
    M cpan/Test-Harness/lib/TAP/Parser/Scheduler/Spinner.pm
    M cpan/Test-Harness/lib/TAP/Parser/Source.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler/Executable.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler/File.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler/Handle.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler/Perl.pm
    M cpan/Test-Harness/lib/TAP/Parser/SourceHandler/RawTAP.pm
    M cpan/Test-Harness/lib/TAP/Parser/YAMLish/Reader.pm
    M cpan/Test-Harness/lib/TAP/Parser/YAMLish/Writer.pm
    M cpan/Test-Harness/lib/Test/Harness.pm

  Log Message:
  -----------
  TAP::Harness: Move timer initialization

Prior to this commit, the timers for counting elapsed time and CPU usage
were begun when a job's first output appears.  This yields inaccurate
results.  These results are saved in t/test_state for future runs so
that they can start the longest-running tests first, which leads to
using the available cores more efficiently.  (If you start a long running
test after everything else is nearly done, you have to wait for it to
finish before the suite as a whole is; if you start the long ones first,
and the shortest last, you don't have to wait very long for any
stragglers to complete.)  Inaccurate results here lead to this
situation, which we were often seeing in the podcheck.t test.

The worst case is if there is heavy computation at the beginning of the
test being run.  podcheck, for example, examines all the pods in the
directory structure to find which links to other pods do or do not have
corresponding anchors.  Output doesn't happen until the analysis is
complete.  On my system, this takes over 30 seconds, but prior to this
commit, what was noted was just the time required to do the output,
about 200 milliseconds.  The result was that podcheck was viewed as
being one of the shortest tests run, so was started late in the process,
and generally held up the completion of it.

This commit by itself doesn't improve the test completion very much,
because, test tests are run a whole directory at a time, and the
directory podcheck is in, for example, is run last.  The next commit
addresses that.


  Commit: 3c204b64feeffd491b29dbbbb13dc380f8e4f0b5
      https://github.com/Perl/perl5/commit/3c204b64feeffd491b29dbbbb13dc380f8e4f0b5
  Author: Karl Williamson <khw@cpan.org>
  Date:   2020-10-18 (Sun, 18 Oct 2020)

  Changed paths:
    M t/harness

  Log Message:
  -----------
  XXX env name: t/harness: Add option for faster test suite execution

This commit adds an environment variable, XXX, which if set to non-zero
increases the parallelism in the execution of the test suite, speeding
it up on systems with multiple cores.

Normally, there are two main test sections, one for core and the second
for non-core tests, and the testing of the non-core one doesn't begin
until the first is complete.  Within each section, there are a number of
test categories, like 're' for regular expressions, and 'JSON::PP' for
the pure perl implementation of JSON.

Within each category, there are various single .t test files.  Some
categories can have those be tested in parallel; some require them to be
done in a particular order, say because an earlier .t does setup for
subsequent ones.  We already have this capability.

Completion of all the tests in a category is not needed before those of
another category can be started.  This is how it already works.

However, the core section categories are ordered so that they begin in a
logical order for someone trying to get perl to work.  First to start
are the basic sanity tests, then by roughly decreasing order of
widespread use in perl programs in the wild, with the final two
categories, porting and perf, being mainly of use to perl5 porters.
These two categories aren't started until all the tests in the earlier
categories are started.  We have some long running tests in those two
categories, and generally they delay the start of the entire second section.

If those long running tests could be started sooner, shorter tests in
the first section could be run in parallel with them, increasing the
average CPU utilization, and the second section could begin (and hence
end) earlier, shortening the total elapsed execution time of the entire
suite.

The second section has some very long running tests.  JSON-PP is one of
them.  If it could run in parallel with tests from the first section,
that would also speed up the completion of the suite.

The environment variable added by this commit does both things.  The
basic sanity test categories in the first section continue to be started
before anything else.  But then all other tests are run in decreasing
order of elapsed time they take to run, removing the boundaries between
some categories, and between the two sections.

The gain from this increases as the number of jobs run in parallel does;
slower high core platforms have the highest increase.  On the old
dromedary with 24 cores, the gain is 20%, almost 2 minutes.  On my more
modern box with 12 cores, it is 8%.


  Commit: 0ee435a6a41e8088c6d59f1cf00e9dfa8cbf5bfc
      https://github.com/Perl/perl5/commit/0ee435a6a41e8088c6d59f1cf00e9dfa8cbf5bfc
  Author: Karl Williamson <khw@cpan.org>
  Date:   2020-10-18 (Sun, 18 Oct 2020)

  Changed paths:
    M regcharclass.h
    M regen/regcharclass.pl
    M regen/regcharclass_multi_char_folds.pl
    M regexec.c
    M regexp.h

  Log Message:
  -----------
  smoke


Compare: https://github.com/Perl/perl5/compare/6971bbdab53a...0ee435a6a41e



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