From 761416ef91d819d84a11222ec5bc3cbc66d3ddac Mon Sep 17 00:00:00 2001 From: Abhradeep Chakraborty Date: Sun, 14 Aug 2022 16:55:11 +0000 Subject: [PATCH] bitmap-lookup-table: add performance tests for lookup table Add performance tests to verify the performance of lookup table. `p5310-pack-bitmaps.sh` contain tests with and without lookup table. `p5312-pack-bitmaps-revs.sh` contain same tests with and without lookup table but with `pack.writeReverseIndex` enabled. Lookup table makes Git run faster in most of the cases. Below is the result of `t/perf/p5310-pack-bitmaps.sh`.`perf/p5326-multi-pack-bitmaps.sh` gives similar result. The repository used in the test is linux kernel. Test this tree ----------------------------------------------------------------------- 5310.4: enable lookup table: false 0.01(0.00+0.00) 5310.5: repack to disk 320.89(230.20+23.45) 5310.6: simulated clone 14.04(5.78+1.79) 5310.7: simulated fetch 1.95(3.05+0.20) 5310.8: pack to file (bitmap) 44.73(20.55+7.45) 5310.9: rev-list (commits) 0.78(0.46+0.10) 5310.10: rev-list (objects) 4.07(3.97+0.08) 5310.11: rev-list with tag negated via --not 0.06(0.02+0.03) --all (objects) 5310.12: rev-list with negative tag (objects) 0.21(0.15+0.05) 5310.13: rev-list count with blob:none 0.24(0.17+0.06) 5310.14: rev-list count with blob:limit=1k 7.07(5.92+0.48) 5310.15: rev-list count with tree:0 0.25(0.17+0.07) 5310.16: simulated partial clone 5.67(3.28+0.64) 5310.18: clone (partial bitmap) 16.05(8.34+1.86) 5310.19: pack to file (partial bitmap) 59.76(27.22+7.43) 5310.20: rev-list with tree filter (partial bitmap) 0.90(0.18+0.16) 5310.24: enable lookup table: true 0.01(0.00+0.00) 5310.25: repack to disk 319.73(229.30+23.01) 5310.26: simulated clone 13.69(5.72+1.78) 5310.27: simulated fetch 1.84(3.02+0.16) 5310.28: pack to file (bitmap) 45.63(20.67+7.50) 5310.29: rev-list (commits) 0.56(0.39+0.8) 5310.30: rev-list (objects) 3.77(3.74+0.08) 5310.31: rev-list with tag negated via --not 0.05(0.02+0.03) --all (objects) 5310.32: rev-list with negative tag (objects) 0.21(0.15+0.05) 5310.33: rev-list count with blob:none 0.23(0.17+0.05) 5310.34: rev-list count with blob:limit=1k 6.65(5.72+0.40) 5310.35: rev-list count with tree:0 0.23(0.16+0.06) 5310.36: simulated partial clone 5.57(3.26+0.59) 5310.38: clone (partial bitmap) 15.89(8.39+1.84) 5310.39: pack to file (partial bitmap) 58.32(27.55+7.47) 5310.40: rev-list with tree filter (partial bitmap) 0.73(0.18+0.15) Test 4-15 are tested without using lookup table. Same tests are repeated in 16-30 (using lookup table). Mentored-by: Taylor Blau Co-Mentored-by: Kaartic Sivaraam Signed-off-by: Abhradeep Chakraborty Reviewed-by: Taylor Blau Signed-off-by: Junio C Hamano --- t/perf/lib-bitmap.sh | 31 +++++++++++ t/perf/p5310-pack-bitmaps.sh | 66 ++++++++++-------------- t/perf/p5311-pack-bitmaps-fetch.sh | 74 ++++++++++++++------------ t/perf/p5312-pack-bitmaps-revs.sh | 35 +++++++++++++ t/perf/p5326-multi-pack-bitmaps.sh | 83 ++++++++++++++++++------------ 5 files changed, 183 insertions(+), 106 deletions(-) create mode 100755 t/perf/p5312-pack-bitmaps-revs.sh diff --git a/t/perf/lib-bitmap.sh b/t/perf/lib-bitmap.sh index 63d3bc7cec..55a8feb1dc 100644 --- a/t/perf/lib-bitmap.sh +++ b/t/perf/lib-bitmap.sh @@ -67,3 +67,34 @@ test_partial_bitmap () { --filter=tree:0 >/dev/null ' } + +test_pack_bitmap () { + test_perf "repack to disk" ' + git repack -ad + ' + + test_full_bitmap + + test_expect_success "create partial bitmap state" ' + # pick a commit to represent the repo tip in the past + cutoff=$(git rev-list HEAD~100 -1) && + orig_tip=$(git rev-parse HEAD) && + + # now kill off all of the refs and pretend we had + # just the one tip + rm -rf .git/logs .git/refs/* .git/packed-refs && + git update-ref HEAD $cutoff && + + # and then repack, which will leave us with a nice + # big bitmap pack of the "old" history, and all of + # the new history will be loose, as if it had been pushed + # up incrementally and exploded via unpack-objects + git repack -Ad && + + # and now restore our original tip, as if the pushes + # had happened + git update-ref HEAD $orig_tip + ' + + test_partial_bitmap +} diff --git a/t/perf/p5310-pack-bitmaps.sh b/t/perf/p5310-pack-bitmaps.sh index 7ad4f237bc..b1399f1007 100755 --- a/t/perf/p5310-pack-bitmaps.sh +++ b/t/perf/p5310-pack-bitmaps.sh @@ -4,51 +4,37 @@ test_description='Tests pack performance using bitmaps' . ./perf-lib.sh . "${TEST_DIRECTORY}/perf/lib-bitmap.sh" -test_perf_large_repo +test_lookup_pack_bitmap () { + test_expect_success 'start the test from scratch' ' + rm -rf * .git + ' -# note that we do everything through config, -# since we want to be able to compare bitmap-aware -# git versus non-bitmap git -# -# We intentionally use the deprecated pack.writebitmaps -# config so that we can test against older versions of git. -test_expect_success 'setup bitmap config' ' - git config pack.writebitmaps true -' + test_perf_large_repo -# we need to create the tag up front such that it is covered by the repack and -# thus by generated bitmaps. -test_expect_success 'create tags' ' - git tag --message="tag pointing to HEAD" perf-tag HEAD -' + # note that we do everything through config, + # since we want to be able to compare bitmap-aware + # git versus non-bitmap git + # + # We intentionally use the deprecated pack.writebitmaps + # config so that we can test against older versions of git. + test_expect_success 'setup bitmap config' ' + git config pack.writebitmaps true + ' -test_perf 'repack to disk' ' - git repack -ad -' + # we need to create the tag up front such that it is covered by the repack and + # thus by generated bitmaps. + test_expect_success 'create tags' ' + git tag --message="tag pointing to HEAD" perf-tag HEAD + ' -test_full_bitmap + test_perf "enable lookup table: $1" ' + git config pack.writeBitmapLookupTable '"$1"' + ' -test_expect_success 'create partial bitmap state' ' - # pick a commit to represent the repo tip in the past - cutoff=$(git rev-list HEAD~100 -1) && - orig_tip=$(git rev-parse HEAD) && + test_pack_bitmap +} - # now kill off all of the refs and pretend we had - # just the one tip - rm -rf .git/logs .git/refs/* .git/packed-refs && - git update-ref HEAD $cutoff && - - # and then repack, which will leave us with a nice - # big bitmap pack of the "old" history, and all of - # the new history will be loose, as if it had been pushed - # up incrementally and exploded via unpack-objects - git repack -Ad && - - # and now restore our original tip, as if the pushes - # had happened - git update-ref HEAD $orig_tip -' - -test_partial_bitmap +test_lookup_pack_bitmap false +test_lookup_pack_bitmap true test_done diff --git a/t/perf/p5311-pack-bitmaps-fetch.sh b/t/perf/p5311-pack-bitmaps-fetch.sh index 47c3fd7581..426fab87e3 100755 --- a/t/perf/p5311-pack-bitmaps-fetch.sh +++ b/t/perf/p5311-pack-bitmaps-fetch.sh @@ -3,42 +3,52 @@ test_description='performance of fetches from bitmapped packs' . ./perf-lib.sh -test_perf_default_repo - -test_expect_success 'create bitmapped server repo' ' - git config pack.writebitmaps true && - git repack -ad -' - -# simulate a fetch from a repository that last fetched N days ago, for -# various values of N. We do so by following the first-parent chain, -# and assume the first entry in the chain that is N days older than the current -# HEAD is where the HEAD would have been then. -for days in 1 2 4 8 16 32 64 128; do - title=$(printf '%10s' "($days days)") - test_expect_success "setup revs from $days days ago" ' - now=$(git log -1 --format=%ct HEAD) && - then=$(($now - ($days * 86400))) && - tip=$(git rev-list -1 --first-parent --until=$then HEAD) && - { - echo HEAD && - echo ^$tip - } >revs +test_fetch_bitmaps () { + test_expect_success 'setup test directory' ' + rm -fr * .git ' - test_perf "server $title" ' - git pack-objects --stdout --revs \ - --thin --delta-base-offset \ - tmp.pack + test_perf_default_repo + + test_expect_success 'create bitmapped server repo' ' + git config pack.writebitmaps true && + git config pack.writeBitmapLookupTable '"$1"' && + git repack -ad ' - test_size "size $title" ' - wc -c revs + ' - test_perf "client $title" ' - git index-pack --stdin --fix-thin tmp.pack + ' + + test_size "size $title" ' + wc -c