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>