Add a git GIT_PERF_MAKE_COMMAND variable to compliment the existing
GIT_PERF_MAKE_OPTS facility. This allows specifying an arbitrary shell
command to execute instead of 'make'.
This is useful e.g. in cases where the name, semantics or defaults of
a Makefile flag have changed over time. It can even be used to change
the contents of the tree, useful for monkeypatching ancient versions
of git to get them to build.
This opens Pandora's box in some ways, it's now possible to
"jailbreak" the perf environment and e.g. modify the source tree via
this arbitrary instead of just issuing a custom "make" command, such a
command has to be re-entrant in the sense that subsequent perf runs
will re-use the possibly modified tree.
It would be pointless to try to mitigate or work around that caveat in
a tool purely aimed at Git developers, so this change makes no attempt
to do so.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 7501b59 (perf: make the tests work in worktrees,
2016-05-13) introduced the use of "git rev-parse --git-path"
in the perf-lib setup code. Because the to-be-tested version
of git is at the front of the $PATH when this code runs,
this means we cannot use modern versions of t/perf to test
versions of git older than v2.5.0 (when that option was
introduced).
This is a symptom of a more general problem. The t/perf
suite is essentially independent of git versions, and
ideally we would be able to run the most modern and complete
set of tests across many historical versions (to see how
they compare). But any setup code they run is therefore
required to use the lowest common denominator we expect to
test.
So let's introduce a new variable, $MODERN_GIT, that we can
use both in perf-lib and in the test setup to get a reliable
set of git features (we might change git and break some
tests, of course, but $MODERN_GIT is tied to the same
version of git as the t/perf scripts, so they can be fixed
or adjusted together).
This commit fixes the "--git-path" case, but does not
mass-convert existing setup code to use $MODERN_GIT. Most
setup code is fairly vanilla and will work with effectively
all versions. But now the tool is there to fix any other
issues we find going forward.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Currently the documentation of GIT_PERF_REPEAT_COUNT says the default is
five while "perf-lib.sh" uses a value of three as a default.
Update the documentation so that it is consistent with the code.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This introduces a performance testing framework under t/perf/. It
tries to be as close to the test-lib.sh infrastructure as possible,
and thus should be easy to get used to for git developers.
The following points were considered for the implementation:
1. You usually want to compare arbitrary revisions/build trees against
each other. They may not have the performance test under
consideration, or even the perf-lib.sh infrastructure.
To cope with this, the 'run' script lets you specify arbitrary
build dirs and revisions. It even automatically builds the revisions
if it doesn't have them at hand yet.
2. Usually you would not want to run all tests. It would take too
long anyway. The 'run' script lets you specify which tests to run;
or you can also do it manually. There is a Makefile for
discoverability and 'make clean', but it is not meant for
real-world use.
3. Creating test repos from scratch in every test is extremely
time-consuming, and shipping or downloading such large/weird repos
is out of the question.
We leave this decision to the user. Two different sizes of test
repos can be configured, and the scripts just copy one or more of
those (using hardlinks for the object store). By default it tries
to use the build tree's git.git repository.
This is fairly fast and versatile. Using a copy instead of a clone
preserves many properties that the user may want to test for, such
as lots of loose objects, unpacked refs, etc.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
