Re: [ANNOUNCE] Git v2.19.0-rc0
From: Derrick Stolee <hidden>
Date: 2018-08-21 20:41:06
On 8/20/2018 6:13 PM, Junio C Hamano wrote:
An early preview release Git v2.19.0-rc0 is now available for testing at the usual places.
As part of testing the release candidate, I ran the performance suite against a fresh clone of the Linux repository using v2.18.0 and v2.19.0-rc0 (also: GIT_PERF_REPEAT_COUNT=10). I found a few nice improvements, but I also found a possible regression in tree walking. I say "tree walking" because it was revealed using p0001-rev-list.sh, but only with the "--objects" flag. I also saw some similar numbers on 'git log --raw'. Test v2.18.0 v2.19.0-rc0 -------------------------------------------------------------------------------------------- 0001.1: rev-list --all 6.69(6.33+0.35) 6.52(6.20+0.31) -2.5% 0001.2: rev-list --all --objects 52.14(47.43+1.02) 57.15(51.09+1.18) +9.6% To me, 9.6% seems out of the range of just noise for this length of a command, but I could be wrong. Could anyone else try to repro these results? (This may also not just be tree-walking, but general pack-file loading and decompression, since I computed and stored a commit-graph file. Hence, commits are not being parsed from the pack-file by either command.) Aside: the perf results were not all bad. Here was an interesting improvement: Test v2.18.0 v2.19.0-rc0 -------------------------------------------------------------------------------------------- 0002.1: read_cache/discard_cache 1000 times 5.63(5.30+0.32) 3.34(3.03+0.30) -40.7% Thanks, -Stolee