Commit Graph

3 Commits

Author SHA1 Message Date
Jonathan Tan
67f2825174 t/perf: export variable used in other blocks
In p0001, a variable was created in a test_expect_success block to be
used in later test_perf blocks, but was not exported. This caused the
variable to not appear in those blocks (this can be verified by writing
'test -n "$commit"' in those blocks), resulting in a slightly different
invocation than what was intended. Export that variable.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-03 10:54:42 -08:00
Jeff King
ea97002fc9 t/perf: time rev-list with UNINTERESTING commits
We time a straight "rev-list --all" and its "--object"
counterpart, both going all the way to the root. However, we
do not time a partial history walk. This patch adds an
extreme case: a walk over a very small slice of history, but
with a very large set of UNINTERESTING tips. This is similar
to the connectivity check run by git on a small fetch, or
the walk done by any pre-receive hooks that want to check
incoming commits.

This test reveals a performance regression in git v1.8.4.2,
caused by fbd4a70 (list-objects: mark more commits as edges
in mark_edges_uninteresting, 2013-08-16):

Test                                             fbd4a703^         fbd4a703
------------------------------------------------------------------------------------------
0001.1: rev-list --all                           0.69(0.67+0.02)   0.69(0.68+0.01) +0.0%
0001.2: rev-list --all --objects                 3.47(3.44+0.02)   3.48(3.44+0.03) +0.3%
0001.4: rev-list $commit --not --all             0.04(0.04+0.00)   0.04(0.04+0.00) +0.0%
0001.5: rev-list --objects $commit --not --all   0.04(0.03+0.00)   0.27(0.24+0.02) +575.0%

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-21 14:46:17 -08:00
Thomas Rast
342e9ef2d9 Introduce a performance testing framework
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>
2012-02-17 08:21:22 -08:00