The 3.x tree has been out for a while now. The -2.6 repository name survived the initial release [1], but kernel.org now only lists 'linux.git' (for aegl as well as torvalds) [2]. [1]: http://article.gmane.org/gmane.linux.kernel/1147422 On 2011-05-30 01:47:57 GMT, Linus Torvalds wrote: > ... yes, that means that my git tree is still called > "linux-2.6.git" on kernel.org. [2]: http://git.kernel.org/cgit/ Signed-off-by: W. Trevor King <wking@tremily.us> Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
			
				
	
	
		
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			147 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
Git performance tests
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=====================
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This directory holds performance testing scripts for git tools.  The
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first part of this document describes the various ways in which you
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can run them.
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When fixing the tools or adding enhancements, you are strongly
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encouraged to add tests in this directory to cover what you are
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trying to fix or enhance.  The later part of this short document
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describes how your test scripts should be organized.
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Running Tests
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-------------
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The easiest way to run tests is to say "make".  This runs all
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the tests on the current git repository.
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    === Running 2 tests in this tree ===
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    [...]
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    Test                                     this tree
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    ---------------------------------------------------------
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    0001.1: rev-list --all                   0.54(0.51+0.02)
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    0001.2: rev-list --all --objects         6.14(5.99+0.11)
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    7810.1: grep worktree, cheap regex       0.16(0.16+0.35)
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    7810.2: grep worktree, expensive regex   7.90(29.75+0.37)
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    7810.3: grep --cached, cheap regex       3.07(3.02+0.25)
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    7810.4: grep --cached, expensive regex   9.39(30.57+0.24)
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You can compare multiple repositories and even git revisions with the
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'run' script:
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    $ ./run . origin/next /path/to/git-tree p0001-rev-list.sh
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where . stands for the current git tree.  The full invocation is
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    ./run [<revision|directory>...] [--] [<test-script>...]
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A '.' argument is implied if you do not pass any other
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revisions/directories.
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You can also manually test this or another git build tree, and then
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call the aggregation script to summarize the results:
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    $ ./p0001-rev-list.sh
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    [...]
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    $ GIT_BUILD_DIR=/path/to/other/git ./p0001-rev-list.sh
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    [...]
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    $ ./aggregate.perl . /path/to/other/git ./p0001-rev-list.sh
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aggregate.perl has the same invocation as 'run', it just does not run
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anything beforehand.
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You can set the following variables (also in your config.mak):
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    GIT_PERF_REPEAT_COUNT
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	Number of times a test should be repeated for best-of-N
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	measurements.  Defaults to 3.
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    GIT_PERF_MAKE_OPTS
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	Options to use when automatically building a git tree for
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	performance testing.  E.g., -j6 would be useful.
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    GIT_PERF_REPO
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    GIT_PERF_LARGE_REPO
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	Repositories to copy for the performance tests.  The normal
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	repo should be at least git.git size.  The large repo should
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	probably be about linux.git size for optimal results.
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	Both default to the git.git you are running from.
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You can also pass the options taken by ordinary git tests; the most
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useful one is:
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--root=<directory>::
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	Create "trash" directories used to store all temporary data during
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	testing under <directory>, instead of the t/ directory.
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	Using this option with a RAM-based filesystem (such as tmpfs)
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	can massively speed up the test suite.
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Naming Tests
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------------
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The performance test files are named as:
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	pNNNN-commandname-details.sh
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where N is a decimal digit.  The same conventions for choosing NNNN as
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for normal tests apply.
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Writing Tests
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-------------
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The perf script starts much like a normal test script, except it
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sources perf-lib.sh:
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	#!/bin/sh
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	#
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	# Copyright (c) 2005 Junio C Hamano
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	#
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	test_description='xxx performance test'
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	. ./perf-lib.sh
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After that you will want to use some of the following:
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	test_perf_default_repo  # sets up a "normal" repository
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	test_perf_large_repo    # sets up a "large" repository
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	test_perf_default_repo sub  # ditto, in a subdir "sub"
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        test_checkout_worktree  # if you need the worktree too
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At least one of the first two is required!
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You can use test_expect_success as usual.  For actual performance
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tests, use
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	test_perf 'descriptive string' '
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		command1 &&
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		command2
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	'
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test_perf spawns a subshell, for lack of better options.  This means
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that
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* you _must_ export all variables that you need in the subshell
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* you _must_ flag all variables that you want to persist from the
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  subshell with 'test_export':
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	test_perf 'descriptive string' '
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		foo=$(git rev-parse HEAD) &&
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		test_export foo
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	'
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  The so-exported variables are automatically marked for export in the
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  shell executing the perf test.  For your convenience, test_export is
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  the same as export in the main shell.
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  This feature relies on a bit of magic using 'set' and 'source'.
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  While we have tried to make sure that it can cope with embedded
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  whitespace and other special characters, it will not work with
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  multi-line data.
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