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[PATCH v4 18/31] perf: add a comparison test of grep regex engines with -F

From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date
May 25, 2017, 19:45 UTC
Message-ID
<20170525194535.9324-19-avarab@gmail.com>
In-Reply-To
<20170525194535.9324-1-avarab@gmail.com>

Add a performance comparison test of grep regex engines given fixed strings.

The current logic in compile_regexp() ignores the engine parameter and uses kwset() to search for these, so this test shows no difference between engines right now:

    $ GIT_PERF_REPEAT_COUNT=10 GIT_PERF_LARGE_REPO=~/g/linux ./run p7821-grep-engines-fixed.sh
    [...]
    Test                             this tree
    ------------------------------------------------
    7821.1: fixed grep int           0.56(1.67+0.68)
    7821.2: basic grep int           0.57(1.70+0.57)
    7821.3: extended grep int        0.59(1.76+0.51)
    7821.4: perl grep int            1.08(1.71+0.55)
    7821.6: fixed grep uncommon      0.23(0.55+0.50)
    7821.7: basic grep uncommon      0.24(0.55+0.50)
    7821.8: extended grep uncommon   0.26(0.55+0.52)
    7821.9: perl grep uncommon       0.24(0.58+0.47)
    7821.11: fixed grep æ            0.36(1.30+0.42)
    7821.12: basic grep æ            0.36(1.32+0.40)
    7821.13: extended grep æ         0.38(1.30+0.42)
    7821.14: perl grep æ             0.35(1.24+0.48)

Only when run with -i via GIT_PERF_7821_GREP_OPTS=' -i' do we avoid avoid going through the same kwset.[ch] codepath, see the "Even when -F..." comment in grep.c. This only kicks for the non-ASCII case:

    $ GIT_PERF_REPEAT_COUNT=10 GIT_PERF_LARGE_REPO=~/g/linux GIT_PERF_7821_GREP_OPTS=' -i' ./run p7821-grep-engines-fixed.sh
    [...]
    Test                                this tree
    ---------------------------------------------------
    7821.1: fixed grep -i int           0.62(2.10+0.57)
    7821.2: basic grep -i int           0.68(1.90+0.61)
    7821.3: extended grep -i int        0.78(1.94+0.57)
    7821.4: perl grep -i int            0.98(1.78+0.74)
    7821.6: fixed grep -i uncommon      0.24(0.44+0.64)
    7821.7: basic grep -i uncommon      0.25(0.56+0.54)
    7821.8: extended grep -i uncommon   0.27(0.62+0.45)
    7821.9: perl grep -i uncommon       0.24(0.59+0.49)
    7821.11: fixed grep -i æ            0.30(0.96+0.39)
    7821.12: basic grep -i æ            0.27(0.92+0.44)
    7821.13: extended grep -i æ         0.28(0.90+0.46)
    7821.14: perl grep -i æ             0.28(0.74+0.49)

I'm planning to change how fixed-string searching happens. This test gives a baseline for comparing performance before & after any such change.

See commit ("perf: add a comparison test of grep regex engines", 2017-04-19) for details on the machine the above test run was executed on.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/perf/p7821-grep-engines-fixed.sh | 41 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100755 t/perf/p7821-grep-engines-fixed.sh
diff --git a/t/perf/p7821-grep-engines-fixed.sh b/t/perf/p7821-grep-engines-fixed.sh
new file mode 100755
index 0000000000..c7ef1e198f
--- /dev/null
+++ b/t/perf/p7821-grep-engines-fixed.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+test_description="Comparison of git-grep's regex engines with -F
+
+Set GIT_PERF_7821_GREP_OPTS in the environment to pass options to
+git-grep. Make sure to include a leading space,
+e.g. GIT_PERF_7821_GREP_OPTS=' -w'. See p7820-grep-engines.sh for more
+options to try.
+"
+
+. ./perf-lib.sh
+
+test_perf_large_repo
+test_checkout_worktree
+
+for pattern in 'int' 'uncommon' 'æ'
+do
+	for engine in fixed basic extended perl
+	do
+		if test $engine = "perl" && ! test_have_prereq PCRE
+		then
+			prereq="PCRE"
+		else
+			prereq=""
+		fi
+		test_perf $prereq "$engine grep$GIT_PERF_7821_GREP_OPTS $pattern" "
+			git -c grep.patternType=$engine grep$GIT_PERF_7821_GREP_OPTS $pattern >'out.$engine' || :
+		"
+	done
+
+	test_expect_success "assert that all engines found the same for$GIT_PERF_7821_GREP_OPTS $pattern" '
+		test_cmp out.fixed out.basic &&
+		test_cmp out.fixed out.extended &&
+		if test_have_prereq PCRE
+		then
+			test_cmp out.fixed out.perl
+		fi
+	'
+done
+
+test_done

-- 
2.13.0.303.g4ebf302169
Previous: Ævar Arnfjörð BjarmasonNext: Ævar Arnfjörð Bjarmason
Message 17 of 32 in “Easy to review grep & pre-PCRE changes”
  1. 00/31 Easy to review grep & pre-PCRE changesÆvar Arnfjörð Bjarmason, May 25, 2017
  2. 01/31 Makefile & configure: reword inaccurate comment about PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  3. 02/31 grep & rev-list doc: stop promising libpcre for --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  4. 04/31 log: add exhaustive tests for pattern style options & configÆvar Arnfjörð Bjarmason, May 25, 2017
  5. 03/31 test-lib: rename the LIBPCRE prerequisite to PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  6. 05/31 log: make --regexp-ignore-case work with --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  7. 07/31 grep: add a test for backreferences in PCRE patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  8. 08/31 grep: change non-ASCII -i test to stop using --debugÆvar Arnfjörð Bjarmason, May 25, 2017
  9. 06/31 grep: add a test asserting that --perl-regexp dies when !PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  10. 09/31 grep: add tests for --threads=N and grep.threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  11. 10/31 grep: amend submodule recursion test for regex engine testingÆvar Arnfjörð Bjarmason, May 25, 2017
  12. 11/31 grep: add tests for grep pattern types being passed to submodulesÆvar Arnfjörð Bjarmason, May 25, 2017
  13. 12/31 grep: add a test helper function for less verbose -f \0 testsÆvar Arnfjörð Bjarmason, May 25, 2017
  14. 13/31 grep: prepare for testing binary regexes containing rx metacharactersÆvar Arnfjörð Bjarmason, May 25, 2017
  15. 14/31 grep: add tests to fix blind spots with \0 patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  16. 16/31 perf: emit progress output when unpacking & buildingÆvar Arnfjörð Bjarmason, May 25, 2017
  17. 18/31 perf: add a comparison test of grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  18. 17/31 perf: add a comparison test of grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  19. 15/31 perf: add a GIT_PERF_MAKE_COMMAND for when *_MAKE_OPTS won't doÆvar Arnfjörð Bjarmason, May 25, 2017
  20. 19/31 perf: add a comparison test of log --grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  21. 20/31 perf: add a comparison test of log --grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  22. 24/31 grep: change the internal PCRE macro names to be PCRE1Ævar Arnfjörð Bjarmason, May 25, 2017
  23. 23/31 grep: factor test for \0 in grep patterns into a functionÆvar Arnfjörð Bjarmason, May 25, 2017
  24. 21/31 grep: catch a missing enum in switch statementÆvar Arnfjörð Bjarmason, May 25, 2017
  25. 22/31 grep: remove redundant regflags assignmentsÆvar Arnfjörð Bjarmason, May 25, 2017
  26. 28/31 pack-objects & index-pack: add test for --threads warningÆvar Arnfjörð Bjarmason, May 25, 2017
  27. 30/31 grep: given --threads with NO_PTHREADS=YesPlease, warnÆvar Arnfjörð Bjarmason, May 25, 2017
  28. 25/31 grep: change internal *pcre* variable & function names to be *pcre1*Ævar Arnfjörð Bjarmason, May 25, 2017
  29. 31/31 grep: assert that threading is enabled when calling grep_{lock,unlock}Ævar Arnfjörð Bjarmason, May 25, 2017
  30. 29/31 pack-objects: fix buggy warning about threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  31. 27/31 test-lib: add a PTHREADS prerequisiteÆvar Arnfjörð Bjarmason, May 25, 2017
  32. 26/31 grep: move is_fixed() earlier to avoid forward declarationÆvar Arnfjörð Bjarmason, May 25, 2017

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