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2025-11-03Merge branch 'rs/merge-base-optim'Junio C Hamano1-0/+101
The code to walk revision graph to compute merge base has been optimized. * rs/merge-base-optim: commit-reach: avoid commit_list_insert_by_date()
2025-10-24commit-reach: avoid commit_list_insert_by_date()René Scharfe1-0/+101
Building a list using commit_list_insert_by_date() has quadratic worst case complexity. Avoid it by just appending in the loop and sorting at the end. The number of merge bases is usually small, so don't expect speedups in normal repositories. It has no limit, though. The added perf test shows a nice improvement when dealing with 16384 merge bases: Test v2.51.1 HEAD ----------------------------------------------------------------- 6010.2: git merge-base 0.55(0.54+0.00) 0.03(0.02+0.00) -94.5% Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-28t/perf: add last-modified perf scriptToon Claes1-0/+22
This just runs some simple last-modified commands. We already test correctness in the regular suite, so this is just about finding performance regressions from one version to another. Based-on-patch-by: Jeff King <peff@peff.net> Signed-off-by: Toon Claes <toon@iotcl.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-07-28Merge branch 'rs/pop-recent-commit-with-prio-queue'Junio C Hamano1-0/+71
The pop_most_recent_commit() function can have quite expensive worst case performance characteristics, which has been optimized by using prio-queue data structure. * rs/pop-recent-commit-with-prio-queue: commit: use prio_queue_replace() in pop_most_recent_commit() prio-queue: add prio_queue_replace() commit: convert pop_most_recent_commit() to prio_queue
2025-07-22commit: convert pop_most_recent_commit() to prio_queueRené Scharfe1-0/+71
pop_most_recent_commit() calls commit_list_insert_by_date() for parent commits, which is itself called in a loop. This can lead to quadratic complexity if there are many merges. Replace the commit_list with a prio_queue to ensure logarithmic worst case complexity and convert all three users. Add a performance test that exercises one of them using a pathological history that consists of 50% merges and 50% root commits to demonstrate the speedup: Test v2.50.1 HEAD ---------------------------------------------------------------------- 1501.2: rev-parse ':/65535' 2.48(2.47+0.00) 0.20(0.19+0.00) -91.9% Alas, sane histories don't benefit from the conversion much, and traversing Git's own history takes a 1% performance hit on my machine: $ hyperfine -w3 -L git ./git_2.50.1,./git '{git} rev-parse :/^Initial.revision' Benchmark 1: ./git_2.50.1 rev-parse :/^Initial.revision Time (mean ± σ): 1.071 s ± 0.004 s [User: 1.052 s, System: 0.017 s] Range (min … max): 1.067 s … 1.078 s 10 runs Benchmark 2: ./git rev-parse :/^Initial.revision Time (mean ± σ): 1.079 s ± 0.003 s [User: 1.060 s, System: 0.017 s] Range (min … max): 1.074 s … 1.083 s 10 runs Summary ./git_2.50.1 rev-parse :/^Initial.revision ran 1.01 ± 0.00 times faster than ./git rev-parse :/^Initial.revision Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-06-17Merge branch 'ds/path-walk-2'Junio C Hamano1-15/+22
"git pack-objects" learns to find delta bases from blobs at the same path, using the --path-walk API. * ds/path-walk-2: pack-objects: allow --shallow and --path-walk path-walk: add new 'edge_aggressive' option pack-objects: thread the path-based compression pack-objects: refactor path-walk delta phase scalar: enable path-walk during push via config pack-objects: enable --path-walk via config repack: add --path-walk option t5538: add tests to confirm deltas in shallow pushes pack-objects: introduce GIT_TEST_PACK_PATH_WALK p5313: add performance tests for --path-walk pack-objects: update usage to match docs pack-objects: add --path-walk option pack-objects: extract should_attempt_deltas()
2025-05-28Merge branch 'kn/passing-leak-tests'Junio C Hamano2-6/+0
Remove the leftover hints to the test framework to mark tests that do not pass the leak checker tests, as they should no longer be needed. * kn/passing-leak-tests: t: remove unexpected SANITIZE_LEAK variables
2025-05-27Merge branch 'ds/sparse-apply-add-p'Junio C Hamano1-0/+3
"git apply" and "git add -i/-p" code paths no longer unnecessarily expand sparse-index while working. * ds/sparse-apply-add-p: p2000: add performance test for patch-mode commands reset: integrate sparse index with --patch git add: make -p/-i aware of sparse index apply: integrate with the sparse index
2025-05-20t: remove unexpected SANITIZE_LEAK variablesKarthik Nayak2-6/+0
As of 1fc7ddf35b (test-lib: unconditionally enable leak checking, 2024-11-20), both the `GIT_TEST_PASSING_SANITIZE_LEAK` and `TEST_PASSES_SANITIZE_LEAK` variables no longer have any meaning, the leak checks are enabled by default. However, some newly added tests include them by mistake. Let's clean this up. Signed-off-by: Karthik Nayak <karthik.188@gmail.com> Acked-by: Justin Tobler <jltobler@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16repack: add --path-walk optionDerrick Stolee1-10/+8
Since 'git pack-objects' supports a --path-walk option, allow passing it through in 'git repack'. This presents interesting testing opportunities for comparing the different repacking strategies against each other. Add the --path-walk option to the performance tests in p5313. For the microsoft/fluentui repo [1] checked out at a specific commit [2], the --path-walk tests in p5313 look like this: Test this tree ------------------------------------------------------------------------- 5313.18: thin pack with --path-walk 0.08(0.06+0.02) 5313.19: thin pack size with --path-walk 18.4K 5313.20: big pack with --path-walk 2.10(7.80+0.26) 5313.21: big pack size with --path-walk 19.8M 5313.22: shallow fetch pack with --path-walk 1.62(3.38+0.17) 5313.23: shallow pack size with --path-walk 33.6M 5313.24: repack with --path-walk 81.29(96.08+0.71) 5313.25: repack size with --path-walk 142.5M [1] https://github.com/microsoft/fluentui [2] e70848ebac1cd720875bccaa3026f4a9ed700e08 Along with the earlier tests in p5313, I'll instead reformat the comparison as follows: Repack Method Pack Size Time --------------------------------------- Hash v1 439.4M 87.24s Hash v2 161.7M 21.51s Path Walk 142.5M 81.29s There are a few things to notice here: 1. The benefits of --name-hash-version=2 over --name-hash-version=1 are significant, but --path-walk still compresses better than that option. 2. The --path-walk command is still using --name-hash-version=1 for the second pass of delta computation, using the increased name hash collisions as a potential method for opportunistic compression on top of the path-focused compression. 3. The --path-walk algorithm is currently sequential and does not use multiple threads for delta compression. Threading will be implemented in a future change so the computation time will improve to better compete in this metric. There are small benefits in size for my copy of the Git repository: Repack Method Pack Size Time --------------------------------------- Hash v1 248.8M 30.44s Hash v2 249.0M 30.15s Path Walk 213.2M 142.50s As well as in the nodejs/node repository [3]: Repack Method Pack Size Time --------------------------------------- Hash v1 739.9M 71.18s Hash v2 764.6M 67.82s Path Walk 698.1M 208.10s [3] https://github.com/nodejs/node This benefit also repeats in my copy of the Linux kernel repository: Repack Method Pack Size Time --------------------------------------- Hash v1 2.5G 554.41s Hash v2 2.5G 549.62s Path Walk 2.2G 1562.36s It is important to see that even when the repository shape does not have many name-hash collisions, there is a slight space boost to be found using this method. As this repacking strategy was released in Git for Windows 2.47.0, some users have reported cases where the --path-walk compression is slightly worse than the --name-hash-version=2 option. In those cases, it may be beneficial to combine the two options. However, there has not been a released version of Git that has both options and I don't have access to these repos for testing. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16p5313: add performance tests for --path-walkDerrick Stolee1-14/+23
The previous change added a --path-walk option to 'git pack-objects'. Create a performance test that demonstrates the time and space benefits of the feature. In order to get an appropriate comparison, we need to avoid reusing deltas and recompute them from scratch. Compare the creation of a thin pack representing a small push and the creation of a relatively large non-thin pack. Running on my copy of the Git repository results in this data (removing the repack tests for --name-hash-version): Test this tree ------------------------------------------------------------------------ 5313.2: thin pack with --name-hash-version=1 0.02(0.01+0.01) 5313.3: thin pack size with --name-hash-version=1 1.6K 5313.4: big pack with --name-hash-version=1 2.55(4.20+0.26) 5313.5: big pack size with --name-hash-version=1 16.4M 5313.6: shallow fetch pack with --name-hash-version=1 1.24(2.03+0.08) 5313.7: shallow pack size with --name-hash-version=1 12.2M 5313.10: thin pack with --name-hash-version=2 0.03(0.01+0.01) 5313.11: thin pack size with --name-hash-version=2 1.6K 5313.12: big pack with --name-hash-version=2 1.91(3.23+0.20) 5313.13: big pack size with --name-hash-version=2 16.4M 5313.14: shallow fetch pack with --name-hash-version=2 1.06(1.57+0.10) 5313.15: shallow pack size with --name-hash-version=2 12.5M 5313.18: thin pack with --path-walk 0.03(0.01+0.01) 5313.19: thin pack size with --path-walk 1.6K 5313.20: big pack with --path-walk 2.05(3.24+0.27) 5313.21: big pack size with --path-walk 16.3M 5313.22: shallow fetch pack with --path-walk 1.08(1.66+0.07) 5313.23: shallow pack size with --path-walk 12.4M This can be reformatted as follows: Pack Type Hash v1 Hash v2 Path Walk --------------------------------------------------- thin pack (time) 0.02s 0.03s 0.03s (size) 1.6K 1.6K 1.6K big pack (time) 2.55s 1.91s 2.05s (size) 16.4M 16.4M 16.3M shallow pack (time) 1.24s 1.06s 1.08s (size) 12.2M 12.5M 12.4M Note that the timing is slower because there is no threading in the --path-walk case (yet). Also, the shallow pack cases are really not using the --path-walk logic right now because it is disabled until some additions are made to the path walk API. The cases where the --path-walk option really shines is when the default name-hash is overwhelmed with unhelpful collisions. An open source example can be found in the microsoft/fluentui repo [1] at a certain commit [2]. [1] https://github.com/microsoft/fluentui [2] e70848ebac1cd720875bccaa3026f4a9ed700e08 Running the tests on this repo results in the following comparison table: Pack Type Hash v1 Hash v2 Path Walk --------------------------------------------------- thin pack (time) 0.36s 0.12s 0.08s (size) 1.2M 22.0K 18.4K big pack (time) 2.00s 2.90s 2.21s (size) 20.4M 25.9M 19.5M shallow pack (time) 1.41s 1.80s 1.65s (size) 34.4M 33.7M 33.6M Notice in particular that in the small thin pack, the time performance has improved from 0.36s for --name-hash-version=1 to 0.08s and this is likely due to the improved size of the resulting pack: 18.4K instead of 1.2M. The relatively new --name-hash-version=2 is competitive with --path-walk (0.12s and 22.0K) but not quite as successful. Finally, running this on a copy of the Linux kernel repository results in these data points: Pack Type Hash v1 Hash v2 Path Walk --------------------------------------------------- thin pack (time) 0.03s 0.13s 0.03s (size) 4.6K 4.6K 4.6K big pack (time) 15.29s 12.32s 13.92s (size) 201.1M 159.1M 158.5M shallow pack (time) 10.88s 22.93s 22.74s (size) 269.2M 273.8M 267.7M Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16p2000: add performance test for patch-mode commandsDerrick Stolee1-0/+3
The previous three changes contributed performance improvements to 'git apply', 'git add -p', and 'git reset -p' when using a sparse index. The improvement to 'git apply' also improved 'git checkout -p'. Add performance tests to demonstrate this (and to help validate that performance remains good in the future). In the truncated test output below, we see that the full checkout performance changes within noise expectations, but the sparse index cases improve 33% and then 96% for 'git add -p' and 41% and then 95% for 'git reset -p'. 'git checkout -p' improves immediatley by 91% because it does not need any change to its builtin. Test HEAD~4 HEAD~3 HEAD~2 HEAD~1 ------------------------------------------------------------------------------------- 2000.118: ... git add -p (full-v3) 0.79 0.79 +0.0% 0.82 +3.8% 0.82 +3.8% 2000.119: ... git add -p (full-v4) 0.74 0.76 +2.7% 0.74 +0.0% 0.76 +2.7% 2000.120: ... git add -p (sparse-v3) 1.94 1.28 -34.0% 0.07 -96.4% 0.07 -96.4% 2000.121: ... git add -p (sparse-v4) 1.93 1.28 -33.7% 0.06 -96.9% 0.06 -96.9% 2000.122: ... git checkout -p (full-v3) 1.18 1.18 +0.0% 1.18 +0.0% 1.19 +0.8% 2000.123: ... git checkout -p (full-v4) 1.10 1.12 +1.8% 1.11 +0.9% 1.11 +0.9% 2000.124: ... git checkout -p (sparse-v3) 1.31 0.11 -91.6% 0.11 -91.6% 0.11 -91.6% 2000.125: ... git checkout -p (sparse-v4) 1.29 0.11 -91.5% 0.11 -91.5% 0.11 -91.5% 2000.126: ... git reset -p (full-v3) 0.81 0.80 -1.2% 0.83 +2.5% 0.83 +2.5% 2000.127: ... git reset -p (full-v4) 0.78 0.77 -1.3% 0.77 -1.3% 0.78 +0.0% 2000.128: ... git reset -p (sparse-v3) 1.58 0.92 -41.8% 0.91 -42.4% 0.07 -95.6% 2000.129: ... git reset -p (sparse-v4) 1.58 0.92 -41.8% 0.92 -41.8% 0.07 -95.6% It is worth noting that if our test was more involved and had multiple hunks to evaluate, then the time spent in 'git apply' would dominate due to multiple index loads and writes. As it stands, we need the sparse index improvement in 'git add -p' itself to confirm this performance improvement. Since the change for 'git add -i' is identical, we avoid a second test case for that similar operation. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-05Merge branch 'ps/meson-build-perf-bench'Junio C Hamano3-7/+33
The build procedure based on Meson learned to drive the benchmarking tests. * ps/meson-build-perf-bench: meson: wire up benchmarking options meson: wire up benchmarks t/perf: fix benchmarks with out-of-tree builds t/perf: use configured PERL_PATH t/perf: fix benchmarks with alternate repo formats
2025-04-29Merge branch 'jk/p5332-testfix'Junio C Hamano1-1/+1
A test fix. * jk/p5332-testfix: p5332: drop "+" from --stdin-packs input
2025-04-29Merge branch 'js/git-perf-env-override'Junio C Hamano1-0/+12
Developer support fix.. * js/git-perf-env-override: perf: do allow `GIT_PERF_*` to be overridden again
2025-04-28t/perf: fix benchmarks with out-of-tree buildsPatrick Steinhardt1-2/+24
The "perf-lib.sh" script is sourced by all of our benchmarking suites to make available common infrastructure. The script assumes that build and source directory are the same, which works for our Makefile. But the assumption breaks with both CMake and Meson, where the build directory can be located in an arbitrary place. Adapt the script so that it works with out-of-tree builds. Most importantly, this requires us to figure out the location of the build directory: - When running benchmarks via our Makefile the build directory is the same as the source directory. We already know to derive the test directory ("t/") via `$(pwd)/..`, which works because we chdir into "t/perf" before executing benchmarks. We can thus derive the build directory by appending another "/.." to that path. - When running benchmarks via Meson the build directory is located at an arbitrary location. The build system thus has to make the path known by exporting the `GIT_BUILD_DIR` environment variable. This change prepares us for wiring up benchmarks in Meson. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-28t/perf: use configured PERL_PATHPatrick Steinhardt3-5/+5
Our benchmarks use a couple of Perl scripts to compute results. These Perl scripts get executed directly, and as the shebang is hardcoded to "/usr/bin/perl" this will fail on any system where the Perl interpreter is located in a different path. Our build infrastructure already lets users configure the location of Perl, which ultimately gets written into the GIT-BUILD-OPTIONS file. This file is being sourced by "test-lib.sh", and consequently we already have the "PERL_PATH" variable available that contains its configured location. Use "PERL_PATH" to execute Perl scripts, which makes them work on more esoteric systems like NixOS. Furthermore, adapt the shebang to use env(1) to execute Perl so that users who have Perl in PATH, but in a non-standard location can execute the script directly. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-28t/perf: fix benchmarks with alternate repo formatsPatrick Steinhardt1-1/+3
Many of our benchmarks operate on a user-defined repository that we copy over before running the benchmarked logic. To keep unintentional side effects caused by on-disk state at bay we skip copying some files. This includes for example hooks, but also the repo's configuration. It is quite sensible to not copy over the configuration, as it is quite easy to inadvertently carry over configuration that may significantly impact the performance measurements. But we cannot fully ignore the configuration either, as it may contain information about the repository format. This will cause failures when for example using a repository with SHA256 object format or the reftable ref format. Fix the issue by parsing the reference and object formats from the source repository and passing them to git-init(1). Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-22p5332: drop "+" from --stdin-packs inputJeff King1-1/+1
This perf script creates a midx by running "git multi-pack-index write" with the "--stdin-packs" option. We feed that stdin by running "find" on .git/objects/pack, using sed to strip off everything but the basename. But that sed invocation also does something peculiar: it adds a "+" to the start of each pack name. This causes the multi-pack-index command to barf. The modified name does not match any pack it knows about, so it ends up with an empty list of packs to put in the midx. And thus nothing matches the --preferred-pack option we pass, which causes it die(). The fix is to remove the extra "+" (which also lets us simplify the sed invocation a bit, as it is now just stripping the leading directories). But that leaves the mystery of why it was ever there in the first place. The answer is that an earlier iteration of the patch series had a concept of "disjoint" packs in the midx. And one of its patches here: https://lore.kernel.org/git/c52d7e7b27a9add4f58b8334db4fe4498af1c90f.1701198172.git.me@ttaylorr.com/ taught read_packs_from_stdin() to treat a leading "+" as marking a disjoint pack. But in the second version of the series, which was ultimately merged, that disjoint concept went away, and the code to parse "+" did likewise. The regular regression tests were adjusted to match, but this case in t/perf was forgotten. Signed-off-by: Jeff King <peff@peff.net> Acked-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-20perf: do allow `GIT_PERF_*` to be overridden againJohannes Schindelin1-0/+12
A common way to run Git's performance benchmarks on repositories other than Git's own repository (which is not exactly large when compared to actually large repositories) is to run them like this: GIT_PERF_LARGE_REPO=/path/to/my/large/repo \ ./p1234-*.sh -ivx Contrary to developers' common expectations, this failed to work when Git was built with a different `GIT_PERF_LARGE_REPO` value specified at build time: That build-time option would have been written to the `GIT-BUILD-OPTIONS` file, which in turn would have been sourced by `test-lib.sh`, which in turn would have been sourced by `perf-lib.sh`, which in turn would have been sourced by the perf test script, _overriding_ the environment variable specified in the way illustrated above. Since perf tests are not run as part of the build, this most likely unintended behavior was not caught and certainly not fixed, as the `GIT_PERF_*` values would have been empty at build-time. However, in 4638e8806e3a (Makefile: use common template for GIT-BUILD-OPTIONS, 2024-12-06), a subtle change of behavior was introduced: Whereas before, a couple of build-time options (the `GIT_PERF_*` ones included) were written to `GIT-BUILD-OPTIONS` only when their values were non-empty. With this commit, they are also written when they are empty. The consequence is that above-mentioned way to run the perf tests will not only fail to pick up the desired `GIT_PERF_*` settings when they were specified differently while building Git, instead the desired settings will be only respected when specified _while building_ Git. Let's work around the original issue, i.e. let `GIT_PERF_*` environment variables override what is recorded in `GIT-BUILD-OPTIONS`. Note that this is just the tip of the iceberg, there are a couple of `GIT_TEST_*` options that may want a similar fix in `test-lib.sh`. Due to time constraints on my side, this here patch focuses exclusively on the `GIT_PERF_*` settings. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-14p7821: fix instructions for testing with threadsPhilippe Blain1-1/+1
In 7b31b55db1 (perf: amend the grep tests to test grep.threads, 2017-12-29), p7821 was tweaked to test the performance of 'git grep' under different number of threads. These tests are run if GIT_PERF_GREP_THREADS is set to a list of thread numbers, but the comment at the top of the file instead mentions GIT_PERF_7821_THREADS. Fix the comment. Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-28p9210: fix 'scalar clone' when running from a detached HEADPhilippe Blain1-1/+2
In p9210-scalar-clone.sh, we test using 'scalar clone' to clone $GIT_PERF_LARGE_REPO (copied locally as 'to-clone'), which defaults to the git.git checkout we are running the test from. When --branch is not specified (as in this test), 'scalar clone' tries to get the default branch of the remote repository by parsing the output of 'git ls-remote --symref $URL HEAD', as implemented in scalar.c:remote_default_branch. When the git.git checkout we are running the test from is in detached HEAD, this fails and we fall back to using the name of the currently checked out branch in the newly initialized repository, which in this case is the value returned earlier in cmd_clone by repo_default_branch_name. We then invoke 'git checkout -t origin/$branch', with $branch being the name we got from remote_default_branch. This invocation fails if '$branch' does not exist as a branch in the current git.git checkout. Fix this by creating a local branch in 'to-clone' in the setup test "enable server-side partial clone", making sure to use '-B' in case a branch named 'test-branch' already exists. Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-28p7821: fix test_perf invocation for prereqsPhilippe Blain1-2/+2
Since 5dccd9155f (t/perf: add iteration setup mechanism to perf-lib, 2022-04-04), perf tests need to declare their prerequisites with '--prereq', after the test title. p7821 was forgotten in that commit, such that running that test on a machine where the PCRE prereq is not satisfied aborts the test with: error: bug in the test script: test_wrapper_ needs 2 positional parameters Fix this by correcting the two 'test_perf' invocations in that test suite. Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-25Merge branch 'ad/set-default-target-in-makefiles'Junio C Hamano1-1/+4
Correct the default target in Documentation/Makefile, and future-proof all Makefiles from similar breakages by declaring the default target (which happens to be "all") upfront. * ad/set-default-target-in-makefiles: Makefile: set default goals in makefiles
2025-02-18Makefile: set default goals in makefilesAdam Dinwoodie1-1/+4
Explicitly set the default goal at the very top of various makefiles. This is already present in some makefiles, but not all of them. In particular, this corrects a regression introduced in a38edab7c8 (Makefile: generate doc versions via GIT-VERSION-GEN, 2024-12-06). That commit added some config files as build targets for the Documentation directory, and put the target configuration in a sensible place. Unfortunately, that sensible place was above any other build target definitions, meaning the default goal changed to being those configuration files only, rather than the HTML and man page documentation. Signed-off-by: Adam Dinwoodie <adam@dinwoodie.org> Helped-by: Junio C Hamano <gitster@pobox.com> Acked-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-12Merge branch 'ds/name-hash-tweaks'Junio C Hamano2-0/+101
"git pack-objects" and its wrapper "git repack" learned an option to use an alternative path-hash function to improve delta-base selection to produce a packfile with deeper history than window size. * ds/name-hash-tweaks: pack-objects: prevent name hash version change test-tool: add helper for name-hash values p5313: add size comparison test pack-objects: add GIT_TEST_NAME_HASH_VERSION repack: add --name-hash-version option pack-objects: add --name-hash-version option pack-objects: create new name-hash function version
2025-01-27test-tool: add helper for name-hash valuesDerrick Stolee1-0/+31
Add a new test-tool helper, name-hash, to output the value of the name-hash algorithms for the input list of strings, one per line. Since the name-hash values can be stored in the .bitmap files, it is important that these hash functions do not change across Git versions. Add a simple test to t5310-pack-bitmaps.sh to provide some testing of the current values. Due to how these functions are implemented, it would be difficult to change them without disturbing these values. The paths used for this test are carefully selected to demonstrate some of the behavior differences of the two current name hash versions, including which conditions will cause them to collide. Create a performance test that uses test_size to demonstrate how collisions occur for these hash algorithms. This test helps inform someone as to the behavior of the name-hash algorithms for their repo based on the paths at HEAD. My copy of the Git repository shows modest statistics around the collisions of the default name-hash algorithm: Test this tree -------------------------------------------------- 5314.1: paths at head 4.5K 5314.2: distinct hash value: v1 4.1K 5314.3: maximum multiplicity: v1 13 5314.4: distinct hash value: v2 4.2K 5314.5: maximum multiplicity: v2 9 Here, the maximum collision multiplicity is 13, but around 10% of paths have a collision with another path. In a more interesting example, the microsoft/fluentui [1] repo had these statistics at time of committing: Test this tree -------------------------------------------------- 5314.1: paths at head 19.5K 5314.2: distinct hash value: v1 8.2K 5314.3: maximum multiplicity: v1 279 5314.4: distinct hash value: v2 17.8K 5314.5: maximum multiplicity: v2 44 [1] https://github.com/microsoft/fluentui That demonstrates that of the nearly twenty thousand path names, they are assigned around eight thousand distinct values. 279 paths are assigned to a single value, leading the packing algorithm to sort objects from those paths together, by size. With the v2 name hash function, the maximum multiplicity lowers to 44, leaving some room for further improvement. In a more extreme example, an internal monorepo had a much worse collision rate: Test this tree -------------------------------------------------- 5314.1: paths at head 227.3K 5314.2: distinct hash value: v1 72.3K 5314.3: maximum multiplicity: v1 14.4K 5314.4: distinct hash value: v2 166.5K 5314.5: maximum multiplicity: v2 138 Here, we can see that the v2 name hash function provides somem improvements, but there are still a number of collisions that could lead to repacking problems at this scale. Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-27p5313: add size comparison testDerrick Stolee1-0/+70
As custom options are added to 'git pack-objects' and 'git repack' to adjust how compression is done, use this new performance test script to demonstrate their effectiveness in performance and size. The recently-added --name-hash-version option allows for testing different name hash functions. Version 2 intends to preserve some of the locality of version 1 while more often breaking collisions due to long filenames. Distinguishing objects by more of the path is critical when there are many name hash collisions and several versions of the same path in the full history, giving a significant boost to the full repack case. The locality of the hash function is critical to compressing something like a shallow clone or a thin pack representing a push of a single commit. This can be seen by running pt5313 on the open source fluentui repository [1]. Most commits will have this kind of output for the thin and big pack cases, though certain commits (such as [2]) will have problematic thin pack size for other reasons. [1] https://github.com/microsoft/fluentui [2] a637a06df05360ce5ff21420803f64608226a875 Checked out at the parent of [2], I see the following statistics: Test HEAD --------------------------------------------------------------- 5313.2: thin pack with version 1 0.37(0.44+0.02) 5313.3: thin pack size with version 1 1.2M 5313.4: big pack with version 1 2.04(7.77+0.23) 5313.5: big pack size with version 1 20.4M 5313.6: shallow fetch pack with version 1 1.41(2.94+0.11) 5313.7: shallow pack size with version 1 34.4M 5313.8: repack with version 1 95.70(676.41+2.87) 5313.9: repack size with version 1 439.3M 5313.10: thin pack with version 2 0.12(0.12+0.06) 5313.11: thin pack size with version 2 22.0K 5313.12: big pack with version 2 2.80(5.43+0.34) 5313.13: big pack size with version 2 25.9M 5313.14: shallow fetch pack with version 2 1.77(2.80+0.19) 5313.15: shallow pack size with version 2 33.7M 5313.16: repack with version 2 33.68(139.52+2.58) 5313.17: repack size with version 2 160.5M To make comparisons easier, I will reformat this output into a different table style: | Test | V1 Time | V2 Time | V1 Size | V2 Size | |--------------|---------|---------|---------|---------| | Thin Pack | 0.37 s | 0.12 s | 1.2 M | 22.0 K | | Big Pack | 2.04 s | 2.80 s | 20.4 M | 25.9 M | | Shallow Pack | 1.41 s | 1.77 s | 34.4 M | 33.7 M | | Repack | 95.70 s | 33.68 s | 439.3 M | 160.5 M | The v2 hash function successfully differentiates the CHANGELOG.md files from each other, which leads to significant improvements in the thin pack (simulating a push of this commit) and the full repack. There is some bloat in the "big pack" scenario and essentially the same results for the shallow pack. In the case of the Git repository, these numbers show some of the issues with this approach: | Test | V1 Time | V2 Time | V1 Size | V2 Size | |--------------|---------|---------|---------|---------| | Thin Pack | 0.02 s | 0.02 s | 1.1 K | 1.1 K | | Big Pack | 1.69 s | 1.95 s | 13.5 M | 14.5 M | | Shallow Pack | 1.26 s | 1.29 s | 12.0 M | 12.2 M | | Repack | 29.51 s | 29.01 s | 237.7 M | 238.2 M | Here, the attempts to remove conflicts in the v2 function seem to cause slight bloat to these sizes. This shows that the Git repository benefits a lot from cross-path delta pairs. The results are similar with the nodejs/node repo: | Test | V1 Time | V2 Time | V1 Size | V2 Size | |--------------|---------|---------|---------|---------| | Thin Pack | 0.02 s | 0.02 s | 1.6 K | 1.6 K | | Big Pack | 4.61 s | 3.26 s | 56.0 M | 52.8 M | | Shallow Pack | 7.82 s | 7.51 s | 104.6 M | 107.0 M | | Repack | 88.90 s | 73.75 s | 740.1 M | 764.5 M | Here, the v2 name-hash causes some size bloat more often than it reduces the size, but it also universally improves performance time, which is an interesting reversal. This must mean that it is helping to short-circuit some delta computations even if it is not finding the most efficient ones. The performance improvement cannot be explained only due to the I/O cost of writing the resulting packfile. The Linux kernel repository was the initial target of the default name hash value, and its naming conventions are practically build to take the most advantage of the default name hash values: | Test | V1 Time | V2 Time | V1 Size | V2 Size | |--------------|----------|----------|---------|---------| | Thin Pack | 0.17 s | 0.07 s | 4.6 K | 4.6 K | | Big Pack | 17.88 s | 12.35 s | 201.1 M | 159.1 M | | Shallow Pack | 11.05 s | 22.94 s | 269.2 M | 273.8 M | | Repack | 727.39 s | 566.95 s | 2.5 G | 2.5 G | Here, the thin and big packs gain some performance boosts in time, with a modest gain in the size of the big pack. The shallow pack, however, is more expensive to compute, likely because similarly-named files across different directories are farther apart in the name hash ordering in v2. The repack also gains benefits in computation time but no meaningful change to the full size. Finally, an internal Javascript repo of moderate size shows significant gains when repacking with --name-hash-version=2 due to it having many name hash collisions. However, it's worth noting that only the full repack case has significant differences from the v1 name hash: | Test | V1 Time | V2 Time | V1 Size | V2 Size | |-----------|-----------|----------|---------|---------| | Thin Pack | 8.28 s | 7.28 s | 16.8 K | 16.8 K | | Big Pack | 12.81 s | 11.66 s | 29.1 M | 29.1 M | | Shallow | 4.86 s | 4.06 s | 42.5 M | 44.1 M | | Repack | 3126.50 s | 496.33 s | 6.2 G | 855.6 M | Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-15Merge branch 'jk/describe-perf'Junio C Hamano1-0/+30
"git describe" optimization. * jk/describe-perf: describe: split "found all tags" and max_candidates logic describe: stop traversing when we run out of names describe: stop digging for max_candidates+1 t/perf: add tests for git-describe t6120: demonstrate weakness in disjoint-root handling
2024-12-04Merge branch 'tb/use-test-file-size-more'Junio C Hamano2-2/+2
Use the right helper program to measure file size in performance tests. * tb/use-test-file-size-more: t/perf: use 'test_file_size' in more places
2024-11-22t/perf: use 'test_file_size' in more placesTaylor Blau2-2/+2
The perf test suite prefers to use test_file_size over 'wc -c' when inside of a test_size block. One advantage is that accidentally writign "wc -c file" (instead of "wc -c <file") does not inadvertently break the tests (since the former will include the filename in the output of wc). Both of the two uses of test_size use "wc -c", but let's convert those to the more conventional test_file_size helper instead. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-11-07t/perf: add tests for git-describeJeff King1-0/+30
We don't have a perf script for git-describe, despite it often being accused of slowness. Let's add a few simple tests to start with. Rather than use the existing tags from our test repo, we'll make our own so that we have a known quantity and position. We'll add a "new" tag near the tip of HEAD, and an "old" one that is at the very bottom. And then our tests are: 1. Describing HEAD naively requires walking all the way down to the old tag as we collect candidates. This gives us a baseline for what "slow" looks like. 2. Doing the same with --candidates=1 can potentially be fast, because we can quie after finding "new". But we don't, and it's also slow. 3. Likewise we should be able to quit when there are no more tags to find. This can happen naturally if a repo has few tags, but also if you restrict the set of tags with --match. Here are the results running against linux.git. Note that I have a commit-graph built for the repo, so "slow" here is ~700ms. Without a commit graph it's more like 9s! Test HEAD -------------------------------------------------------------- 6100.2: describe HEAD 0.70(0.66+0.04) 6100.3: describe HEAD with one max candidate 0.70(0.66+0.04) 6100.4: describe HEAD with one tag 0.70(0.64+0.06) Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-10-10t/perf: fix typosAndrew Kreimer2-3/+3
Fix typos via codespell. Signed-off-by: Andrew Kreimer <algonell@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-14p1500: add is-base performance testsDerrick Stolee1-0/+31
The previous two changes introduced a commit walking heuristic for finding the most likely base branch for a given source. This algorithm walks first-parent histories until reaching a collision. This walk _should_ be very fast. Exceptions include cases where a commit-graph file does not exist, leading to a full walk of all reachable commits to compute generation numbers, or a case where no collision in the first-parent history exists, leading to a walk of all first-parent history to the root commits. The p1500 test script guarantees a complete commit-graph file during its setup, so we will not test that scenario. Do create a new root commit in an effort to test the scenario of parallel first-parent histories. Even with the extra root commit, these tests take no longer than 0.02 seconds on my machine for the Git repository. However, the results are slightly more interesting in a copy of the Linux kernel repository: Test --------------------------------------------------------------- 1500.2: ahead-behind counts: git for-each-ref 0.12 1500.3: ahead-behind counts: git branch 0.12 1500.4: ahead-behind counts: git tag 0.12 1500.5: contains: git for-each-ref --merged 0.04 1500.6: contains: git branch --merged 0.04 1500.7: contains: git tag --merged 0.04 1500.8: is-base check: test-tool reach (refs) 0.03 1500.9: is-base check: test-tool reach (tags) 0.03 1500.10: is-base check: git for-each-ref 0.03 1500.11: is-base check: git for-each-ref (disjoint-base) 0.07 Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24t/perf: implement performance tests for pseudo-merge bitmapsTaylor Blau1-0/+32
Implement a straightforward performance test demonstrating the benefit of pseudo-merge bitmaps by measuring how long it takes to count reachable objects in a few different scenarios: - without bitmaps, to demonstrate a reasonable baseline - with bitmaps, but without pseudo-merges - with bitmaps and pseudo-merges Results from running this test on git.git are as follows: Test this tree ----------------------------------------------------------------------------------- 5333.2: git rev-list --count --all --objects (no bitmaps) 3.54(3.45+0.08) 5333.3: git rev-list --count --all --objects (no pseudo-merges) 0.43(0.40+0.03) 5333.4: git rev-list --count --all --objects (with pseudo-merges) 0.12(0.11+0.01) On a private repository which is much larger, and has many spikey parts of history that aren't merged into the 'master' branch, the results are as follows: Test this tree --------------------------------------------------------------------------------------- 5333.1: git rev-list --count --all --objects (no bitmaps) 122.29(121.31+0.97) 5333.2: git rev-list --count --all --objects (no pseudo-merges) 21.88(21.30+0.58) 5333.3: git rev-list --count --all --objects (with pseudo-merges) 5.05(4.77+0.28) Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-03-16t/perf: avoid redundant use of catBeat Bolli1-1/+1
Take care to redirect stdin, otherwise the output of wc would also contain the file name. Signed-off-by: Beat Bolli <dev+git@drbeat.li> Acked-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-12Merge branch 'tb/multi-pack-verbatim-reuse'Junio C Hamano1-0/+81
Streaming spans of packfile data used to be done only from a single, primary, pack in a repository with multiple packfiles. It has been extended to allow reuse from other packfiles, too. * tb/multi-pack-verbatim-reuse: (26 commits) t/perf: add performance tests for multi-pack reuse pack-bitmap: enable reuse from all bitmapped packs pack-objects: allow setting `pack.allowPackReuse` to "single" t/test-lib-functions.sh: implement `test_trace2_data` helper pack-objects: add tracing for various packfile metrics pack-bitmap: prepare to mark objects from multiple packs for reuse pack-revindex: implement `midx_pair_to_pack_pos()` pack-revindex: factor out `midx_key_to_pack_pos()` helper midx: implement `midx_preferred_pack()` git-compat-util.h: implement checked size_t to uint32_t conversion pack-objects: include number of packs reused in output pack-objects: prepare `write_reused_pack_verbatim()` for multi-pack reuse pack-objects: prepare `write_reused_pack()` for multi-pack reuse pack-objects: pass `bitmapped_pack`'s to pack-reuse functions pack-objects: keep track of `pack_start` for each reuse pack pack-objects: parameterize pack-reuse routines over a single pack pack-bitmap: return multiple packs via `reuse_partial_packfile_from_bitmap()` pack-bitmap: simplify `reuse_partial_packfile_from_bitmap()` signature ewah: implement `bitmap_is_empty()` pack-bitmap: pass `bitmapped_pack` struct to pack-reuse functions ...
2023-12-18Merge branch 'js/update-urls-in-doc-and-comment'Junio C Hamano1-1/+1
Stale URLs have been updated to their current counterparts (or archive.org) and HTTP links are replaced with working HTTPS links. * js/update-urls-in-doc-and-comment: doc: refer to internet archive doc: update links for andre-simon.de doc: switch links to https doc: update links to current pages
2023-12-14t/perf: add performance tests for multi-pack reuseTaylor Blau1-0/+81
To ensure that we don't regress either the size or runtime performance of multi-pack reuse, add a performance test to measure both of these. The test partitions the objects in GIT_TEST_PERF_LARGE_REPO into 1, 10, and 100 packs, and then tries to perform a "clone" at each stage with both single- and multi-pack reuse enabled. Note that the `repack_into_n_chunks()` function in this new test script differs from the existing `repack_into_n()`. The former partitions the repository into N equal-sized chunks, while the latter produces N packs of five commits each (plus their objects), and then another pack with the remainder. On git.git, I can produce the following results on my machine: Test this tree -------------------------------------------------------------------------------- 5332.3: clone for 1-pack scenario (single-pack reuse) 1.57(2.99+0.15) 5332.4: clone size for 1-pack scenario (single-pack reuse) 231.8M 5332.5: clone for 1-pack scenario (multi-pack reuse) 1.79(2.96+0.21) 5332.6: clone size for 1-pack scenario (multi-pack reuse) 231.7M 5332.9: clone for 10-pack scenario (single-pack reuse) 3.89(16.75+0.35) 5332.10: clone size for 10-pack scenario (single-pack reuse) 209.9M 5332.11: clone for 10-pack scenario (multi-pack reuse) 1.56(2.99+0.17) 5332.12: clone size for 10-pack scenario (multi-pack reuse) 224.4M 5332.15: clone for 100-pack scenario (single-pack reuse) 8.24(54.31+0.59) 5332.16: clone size for 100-pack scenario (single-pack reuse) 278.3M 5332.17: clone for 100-pack scenario (multi-pack reuse) 2.13(2.44+0.33) 5332.18: clone size for 100-pack scenario (multi-pack reuse) 357.9M Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-09Merge branch 'vd/for-each-ref-unsorted-optimization'Junio C Hamano1-0/+87
"git for-each-ref --no-sort" still sorted the refs alphabetically which paid non-trivial cost. It has been redefined to show output in an unspecified order, to allow certain optimizations to take advantage of. * vd/for-each-ref-unsorted-optimization: t/perf: add perf tests for for-each-ref ref-filter.c: use peeled tag for '*' format fields for-each-ref: clean up documentation of --format ref-filter.c: filter & format refs in the same callback ref-filter.c: refactor to create common helper functions ref-filter.c: rename 'ref_filter_handler()' to 'filter_one()' ref-filter.h: add functions for filter/format & format-only ref-filter.h: move contains caches into filter ref-filter.h: add max_count and omit_empty to ref_format ref-filter.c: really don't sort when using --no-sort
2023-11-26doc: switch links to httpsJosh Soref1-1/+1
These sites offer https versions of their content. Using the https versions provides some protection for users. Signed-off-by: Josh Soref <jsoref@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-16t/perf: add perf tests for for-each-refVictoria Dye1-0/+87
Add performance tests for 'for-each-ref'. The tests exercise different combinations of filters/formats/options, as well as the overall performance of 'git for-each-ref | git cat-file --batch-check' to demonstrate the performance difference vs. 'git for-each-ref' with "%(*fieldname)" format specifiers. All tests are run against a repository with 40k loose refs - 10k commits, each having a unique: - branch - custom ref (refs/custom/special_*) - annotated tag pointing at the commit - annotated tag pointing at the other annotated tag (i.e., a nested tag) After those tests are finished, the refs are packed with 'pack-refs --all' and the same tests are rerun. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-11-11global: convert trivial usages of `test <expr> -a/-o <expr>`Patrick Steinhardt2-5/+6
Our coding guidelines say to not use `test` with `-a` and `-o` because it can easily lead to bugs. Convert trivial cases where we still use these to instead instead concatenate multiple invocations of `test` via `&&` and `||`, respectively. While not all of the converted instances can cause ambiguity, it is worth getting rid of all of them regardless: - It becomes easier to reason about the code as we do not have to argue why one use of `-a`/`-o` is okay while another one isn't. - We don't encourage people to use these expressions. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-11check-attr: integrate with sparse-indexShuqi Liang1-0/+1
Set the requires-full-index to false for "check-attr". Add a test to ensure that the index is not expanded whether the files are outside or inside the sparse-checkout cone when the sparse index is enabled. The `p2000` tests demonstrate a ~63% execution time reduction for 'git check-attr' using a sparse index. Test before after ----------------------------------------------------------------------- 2000.106: git check-attr -a f2/f4/a (full-v3) 0.05 0.05 +0.0% 2000.107: git check-attr -a f2/f4/a (full-v4) 0.05 0.05 +0.0% 2000.108: git check-attr -a f2/f4/a (sparse-v3) 0.04 0.02 -50.0% 2000.109: git check-attr -a f2/f4/a (sparse-v4) 0.04 0.01 -75.0% Helped-by: Victoria Dye <vdye@github.com> Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-23Merge branch 'sl/worktree-sparse'Junio C Hamano1-0/+1
"git worktree" learned to work better with sparse index feature. * sl/worktree-sparse: worktree: integrate with sparse-index
2023-06-12worktree: integrate with sparse-indexShuqi Liang1-0/+1
The index is read in 'worktree.c' at two points: 1.The 'validate_no_submodules' function, which checks if there are any submodules present in the worktree. 2.The 'check_clean_worktree' function, which verifies if a worktree is 'clean', i.e., there are no untracked or modified but uncommitted files. This is done by running the 'git status' command, and an error message is thrown if the worktree is not clean. Given that 'git status' is already sparse-aware, the function is also sparse-aware. Hence we can just set the requires-full-index to false for "git worktree". Add tests that verify that 'git worktree' behaves correctly when the sparse index is enabled and test to ensure the index is not expanded. The `p2000` tests demonstrate a ~20% execution time reduction for 'git worktree' using a sparse index: (Note:the p2000 test results didn't reflect the huge speedup because of the index reading time is minuscule comparing to the filesystem operations.) Test before after ----------------------------------------------------------------------- 2000.102: git worktree add....(full-v3) 3.15 2.82 -10.5% 2000.103: git worktree add....(full-v4) 3.14 2.84 -9.6% 2000.104: git worktree add....(sparse-v3) 2.59 2.14 -16.4% 2000.105: git worktree add....(sparse-v4) 2.10 1.57 -25.2% Helped-by: Victoria Dye <vdye@github.com> Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Acked-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-18diff-tree: integrate with sparse indexShuqi Liang1-0/+2
The index is read in 'cmd_diff_tree' at two points: 1. The first index read was added in fd66bcc31ff (diff-tree: read the index so attribute checks work in bare repositories, 2017-12-06) to deal with reading '.gitattributes' content. 77efbb366ab (attr: be careful about sparse directories, 2021-09-08) established that, in a sparse index, we do _not_ try to load a '.gitattributes' file from within a sparse directory. 2. The second index access point is involved in rename detection, specifically when reading from stdin.This was initially added in f0c6b2a2fd9 ([PATCH] Optimize diff-tree -[CM]--stdin, 2005-05-27), where 'setup' was set to 'DIFF_SETUP_USE_SIZE_CACHE |DIFF_SETUP_USE_CACHE'. That assignment was later modified to drop the'DIFF_SETUP_USE_CACHE' in ff7fe37b053 (diff.c: move read_index() code back to the caller, 2018-08-13).However, 'DIFF_SETUP_USE_SIZE_CACHE' seems to be unused as of 6e0b8ed6d35 (diff.c: do not use a separate "size cache"., 2007-05-07) and nothing about 'detect_rename' otherwise indicates index usage. Hence we can just set the requires-full-index to false for "diff-tree". Add tests that verify that 'git diff-tree' behaves correctly when the sparse index is enabled and test to ensure the index is not expanded. The `p2000` tests demonstrate a ~98% execution time reduction for 'git diff-tree' using a sparse index: Test before after ----------------------------------------------------------------------- 2000.94: git diff-tree HEAD (full-v3) 0.05 0.04 -20.0% 2000.95: git diff-tree HEAD (full-v4) 0.06 0.05 -16.7% 2000.96: git diff-tree HEAD (sparse-v3) 0.59 0.01 -98.3% 2000.97: git diff-tree HEAD (sparse-v4) 0.61 0.01 -98.4% 2000.98: git diff-tree HEAD -- f2/f4/a (full-v3) 0.05 0.05 +0.0% 2000.99: git diff-tree HEAD -- f2/f4/a (full-v4) 0.05 0.04 -20.0% 2000.100: git diff-tree HEAD -- f2/f4/a (sparse-v3) 0.58 0.01 -98.3% 2000.101: git diff-tree HEAD -- f2/f4/a (sparse-v4) 0.55 0.01 -98.2% Helped-by: Victoria Dye <vdye@github.com> Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-15Merge branch 'sl/diff-files-sparse'Junio C Hamano1-0/+2
Teach "diff-files" not to expand sparse-index unless needed. * sl/diff-files-sparse: diff-files: integrate with sparse index t1092: add tests for `git diff-files`
2023-05-09diff-files: integrate with sparse indexShuqi Liang1-0/+2
Remove full index requirement for `git diff-files`. Refactor the ensure_expanded and ensure_not_expanded functions by introducing a common helper function, ensure_index_state. Add test to ensure the index is no expanded in `git diff-files`. The `p2000` tests demonstrate a ~96% execution time reduction for 'git diff-files' and a ~97% execution time reduction for 'git diff-files' for a file using a sparse index: Test before after ----------------------------------------------------------------------- 2000.94: git diff-files (full-v3) 0.09 0.08 -11.1% 2000.95: git diff-files (full-v4) 0.09 0.09 +0.0% 2000.96: git diff-files (sparse-v3) 0.52 0.02 -96.2% 2000.97: git diff-files (sparse-v4) 0.51 0.02 -96.1% 2000.98: git diff-files -- f2/f4/a (full-v3) 0.06 0.07 +16.7% 2000.99: git diff-files -- f2/f4/a (full-v4) 0.08 0.08 +0.0% 2000.100: git diff-files -- f2/f4/a (sparse-v3) 0.46 0.01 -97.8% 2000.101: git diff-files -- f2/f4/a (sparse-v4) 0.51 0.02 -96.1% Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-27Merge branch 'tb/pack-revindex-on-disk'Junio C Hamano1-2/+1
The on-disk reverse index that allows mapping from the pack offset to the object name for the object stored at the offset has been enabled by default. * tb/pack-revindex-on-disk: t: invert `GIT_TEST_WRITE_REV_INDEX` config: enable `pack.writeReverseIndex` by default pack-revindex: introduce `pack.readReverseIndex` pack-revindex: introduce GIT_TEST_REV_INDEX_DIE_ON_DISK pack-revindex: make `load_pack_revindex` take a repository t5325: mark as leak-free pack-write.c: plug a leak in stage_tmp_packfiles()
2023-04-21Merge branch 'rn/sparse-describe'Junio C Hamano1-0/+3
"git describe --dirty" learns to work better with sparse-index. * rn/sparse-describe: describe: enable sparse index for describe
2023-04-17Merge branch 'sl/sparse-write-tree'Junio C Hamano1-0/+1
"git write-tree" learns to work better with sparse-index. * sl/sparse-write-tree: write-tree: integrate with sparse index
2023-04-13config: enable `pack.writeReverseIndex` by defaultTaylor Blau1-2/+1
Back in e37d0b8730 (builtin/index-pack.c: write reverse indexes, 2021-01-25), Git learned how to read and write a pack's reverse index from a file instead of in-memory. A pack's reverse index is a mapping from pack position (that is, the order that objects appear together in a ".pack") to their position in lexical order (that is, the order that objects are listed in an ".idx" file). Reverse indexes are consulted often during pack-objects, as well as during auxiliary operations that require mapping between pack offsets, pack order, and index index. They are useful in GitHub's infrastructure, where we have seen a dramatic increase in performance when writing ".rev" files[1]. In particular: - an ~80% reduction in the time it takes to serve fetches on a popular repository, Homebrew/homebrew-core. - a ~60% reduction in the peak memory usage to serve fetches on that same repository. - a collective savings of ~35% in CPU time across all pack-objects invocations serving fetches across all repositories in a single datacenter. Reverse indexes are also beneficial to end-users as well as forges. For example, the time it takes to generate a pack containing the objects for the 10 most recent commits in linux.git (representing a typical push) is significantly faster when on-disk reverse indexes are available: $ { git rev-parse HEAD && printf '^' && git rev-parse HEAD~10 } >in $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} pack-objects --delta-base-offset --revs --stdout <in >/dev/null' Benchmark 1: git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null Time (mean ± σ): 543.0 ms ± 20.3 ms [User: 616.2 ms, System: 58.8 ms] Range (min … max): 521.0 ms … 577.9 ms 10 runs Benchmark 2: git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null Time (mean ± σ): 245.0 ms ± 11.4 ms [User: 335.6 ms, System: 31.3 ms] Range (min … max): 226.0 ms … 259.6 ms 13 runs Summary 'git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null' ran 2.22 ± 0.13 times faster than 'git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null' The same is true of writing a pack containing the objects for the 30 most-recent commits: $ { git rev-parse HEAD && printf '^' && git rev-parse HEAD~30 } >in $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} pack-objects --delta-base-offset --revs --stdout <in >/dev/null' Benchmark 1: git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null Time (mean ± σ): 866.5 ms ± 16.2 ms [User: 1414.5 ms, System: 97.0 ms] Range (min … max): 839.3 ms … 886.9 ms 10 runs Benchmark 2: git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null Time (mean ± σ): 581.6 ms ± 10.2 ms [User: 1181.7 ms, System: 62.6 ms] Range (min … max): 567.5 ms … 599.3 ms 10 runs Summary 'git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null' ran 1.49 ± 0.04 times faster than 'git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null' ...and savings on trivial operations like computing the on-disk size of a single (packed) object are even more dramatic: $ git rev-parse HEAD >in $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} cat-file --batch-check="%(objectsize:disk)" <in' Benchmark 1: git.compile -c pack.readReverseIndex=false cat-file --batch-check="%(objectsize:disk)" <in Time (mean ± σ): 305.8 ms ± 11.4 ms [User: 264.2 ms, System: 41.4 ms] Range (min … max): 290.3 ms … 331.1 ms 10 runs Benchmark 2: git.compile -c pack.readReverseIndex=true cat-file --batch-check="%(objectsize:disk)" <in Time (mean ± σ): 4.0 ms ± 0.3 ms [User: 1.7 ms, System: 2.3 ms] Range (min … max): 1.6 ms … 4.6 ms 1155 runs Summary 'git.compile -c pack.readReverseIndex=true cat-file --batch-check="%(objectsize:disk)" <in' ran 76.96 ± 6.25 times faster than 'git.compile -c pack.readReverseIndex=false cat-file --batch-check="%(objectsize:disk)" <in' In the more than two years since e37d0b8730 was merged, Git's implementation of on-disk reverse indexes has been thoroughly tested, both from users enabling `pack.writeReverseIndexes`, and from GitHub's deployment of the feature. The latter has been running without incident for more than two years. This patch changes Git's behavior to write on-disk reverse indexes by default when indexing a pack, which should make the above operations faster for everybody's Git installation after a repack. (The previous commit explains some potential drawbacks of using on-disk reverse indexes in certain limited circumstances, that essentially boil down to a trade-off between time to generate, and time to access. For those limited cases, the `pack.readReverseIndex` escape hatch can be used). [1]: https://github.blog/2021-04-29-scaling-monorepo-maintenance/#reverse-indexes Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-06Merge branch 'ds/ahead-behind'Junio C Hamano1-0/+50
"git for-each-ref" learns '%(ahead-behind:<base>)' that computes the distances from a single reference point in the history with bunch of commits in bulk. * ds/ahead-behind: commit-reach: add tips_reachable_from_bases() for-each-ref: add ahead-behind format atom commit-reach: implement ahead_behind() logic commit-graph: introduce `ensure_generations_valid()` commit-graph: return generation from memory commit-graph: simplify compute_generation_numbers() commit-graph: refactor compute_topological_levels() for-each-ref: explicitly test no matches for-each-ref: add --stdin option
2023-04-04write-tree: integrate with sparse indexShuqi Liang1-0/+1
Update 'git write-tree' to allow using the sparse-index in memory without expanding to a full one. The recursive algorithm for update_one() was already updated in 2de37c5 (cache-tree: integrate with sparse directory entries, 2021-03-03) to handle sparse directory entries in the index. Hence we can just set the requires-full-index to false for "write-tree". The `p2000` tests demonstrate a ~96% execution time reduction for 'git write-tree' using a sparse index: Test before after ----------------------------------------------------------------- 2000.78: git write-tree (full-v3) 0.34 0.33 -2.9% 2000.79: git write-tree (full-v4) 0.32 0.30 -6.3% 2000.80: git write-tree (sparse-v3) 0.47 0.02 -95.8% 2000.81: git write-tree (sparse-v4) 0.45 0.02 -95.6% Signed-off-by: Shuqi Liang <cheskaqiqi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-03describe: enable sparse index for describeRaghul Nanth A1-0/+3
git describe compares the index with the working tree when (and only when) it is run with the "--dirty" flag. This is done by the run_diff_index() function. The function has been made aware of the sparse-index in the series that led to 8d2c3732 (Merge branch 'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the requires-full-index to false for "describe". Performance metrics Test HEAD~1 HEAD ------------------------------------------------------------------------------------------------- 2000.2: git describe --dirty (full-v3) 0.08(0.09+0.01) 0.08(0.06+0.03) +0.0% 2000.3: git describe --dirty (full-v4) 0.09(0.07+0.03) 0.08(0.05+0.04) -11.1% 2000.4: git describe --dirty (sparse-v3) 0.88(0.82+0.06) 0.02(0.01+0.05) -97.7% 2000.5: git describe --dirty (sparse-v4) 0.68(0.60+0.08) 0.02(0.02+0.04) -97.1% 2000.6: echo >>new && git describe --dirty (full-v3) 0.08(0.04+0.05) 0.08(0.05+0.04) +0.0% 2000.7: echo >>new && git describe --dirty (full-v4) 0.08(0.07+0.03) 0.08(0.05+0.04) +0.0% 2000.8: echo >>new && git describe --dirty (sparse-v3) 0.75(0.69+0.07) 0.02(0.03+0.03) -97.3% 2000.9: echo >>new && git describe --dirty (sparse-v4) 0.81(0.73+0.09) 0.02(0.01+0.05) -97.5% Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-31Merge branch 'ds/p2000-fix-grep-sparse'Junio C Hamano1-1/+1
Fix perf test. * ds/p2000-fix-grep-sparse: p2000: remove stray '--sparse' flag from test
2023-03-28p2000: remove stray '--sparse' flag from testDerrick Stolee1-1/+1
This argument was added in 7cae7627c45 (builtin/grep.c: integrate with sparse index, 2022-09-22), but it was a carry-over from an earlier version where the --sparse flag was added to the 'git grep' builtin. This argument does not exist, so currently the p2000-sparse-operations.sh performance test script fails when reaching this step. With this fix, the script works with these numbers for my copy of the Git source code repository: Test HEAD ------------------------------------------------------------ 2000.30: git grep --cached ... (full-v3) 0.34(1.20+0.14) 2000.31: git grep --cached ... (full-v4) 0.31(1.15+0.13) 2000.32: git grep --cached ... (sparse-v3) 0.26(1.13+0.12) 2000.33: git grep --cached ... (sparse-v4) 0.27(1.13+0.12) Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20commit-reach: add tips_reachable_from_bases()Derrick Stolee1-5/+10
Both 'git for-each-ref --merged=<X>' and 'git branch --merged=<X>' use the ref-filter machinery to select references or branches (respectively) that are reachable from a set of commits presented by one or more --merged arguments. This happens within reach_filter(), which uses the revision-walk machinery to walk history in a standard way. However, the commit-reach.c file is full of custom searches that are more efficient, especially for reachability queries that can terminate early when reachability is discovered. Add a new tips_reachable_from_bases() method to commit-reach.c and call it from within reach_filter() in ref-filter.c. This affects both 'git branch' and 'git for-each-ref' as tested in p1500-graph-walks.sh. For the Linux kernel repository, we take an already-fast algorithm and make it even faster: Test HEAD~1 HEAD ------------------------------------------------------------------- 1500.5: contains: git for-each-ref --merged 0.13 0.02 -84.6% 1500.6: contains: git branch --merged 0.14 0.02 -85.7% 1500.7: contains: git tag --merged 0.15 0.03 -80.0% (Note that we remove the iterative 'git rev-list' test from p1500 because it no longer makes sense as a comparison to 'git for-each-ref' and would just waste time running it for these comparisons.) The algorithm is implemented in commit-reach.c in the method tips_reachable_from_base(). This method takes a string_list of tips and assigns the 'util' for each item with the value 1 if the base commit can reach those tips. Like other reachability queries in commit-reach.c, the fastest way to search for "can A reach B?" is to do a depth-first search up to the generation number of B, preferring to explore first parents before later parents. While we must walk all reachable commits up to that generation number when the answer is "no", the depth-first search can answer "yes" much faster than other approaches in most cases. This search becomes trickier when there are multiple targets for the depth-first search. The commits with lower generation number are more likely to be within the history of the start commit, but we don't want to waste time searching commits of low generation number if the commit target with lowest generation number has already been found. The trick here is to take the input commits and sort them by generation number in ascending order. Track the index within this order as min_generation_index. When we find a commit, if its index in the list is equal to min_generation_index, then we can increase the generation number boundary of our search to the next-lowest value in the list. With this mechanism, the number of commits to search is minimized with respect to the depth-first search heuristic. We will walk all commits up to the minimum generation number of a commit that is _not_ reachable from the start, but we will walk only the necessary portion of the depth-first search for the reachable commits of lower generation. Add extra tests for this behavior in t6600-test-reach.sh as the interesting data shape of that repository can sometimes demonstrate corner case bugs. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20for-each-ref: add ahead-behind format atomDerrick Stolee1-0/+45
The previous change implemented the ahead_behind() method, including an algorithm to compute the ahead/behind values for a number of commit tips relative to a number of commit bases. Now, integrate that algorithm as part of 'git for-each-ref' hidden behind a new format atom, ahead-behind. This naturally extends to 'git branch' and 'git tag' builtins, as well. This format allows specifying multiple bases, if so desired, and all matching references are compared against all of those bases. For this reason, failing to read a reference provided from these atoms results in an error. In order to translate the ahead_behind() method information to the format output code in ref-filter.c, we must populate arrays of ahead_behind_count structs. In struct ref_array, we store the full array that will be passed to ahead_behind(). In struct ref_array_item, we store an array of pointers that point to the relvant items within the full array. In this way, we can pull all relevant ahead/behind values directly when formatting output for a specific item. It also ensures the lifetime of the ahead_behind_count structs matches the time that the array is being used. Add specific tests of the ahead/behind counts in t6600-test-reach.sh, as it has an interesting repository shape. In particular, its merging strategy and its use of different commit-graphs would demonstrate over- counting if the ahead_behind() method did not already account for that possibility. Also add tests for the specific for-each-ref, branch, and tag builtins. In the case of 'git tag', there are intersting cases that happen when some of the selected tips are not commits. This requires careful logic around commits_nr in the second loop of filter_ahead_behind(). Also, the test in t7004 is carefully located to avoid being dependent on the GPG prereq. It also avoids using the test_commit helper, as that will add ticks to the time and disrupt the expected timestamps in later tag tests. Also add performance tests in a new p1300-graph-walks.sh script. This will be useful for more uses in the future, but for now compare the ahead-behind counting algorithm in 'git for-each-ref' to the naive implementation by running 'git rev-list --count' processes for each input. For the Git source code repository, the improvement is already obvious: Test this tree --------------------------------------------------------------- 1500.2: ahead-behind counts: git for-each-ref 0.07(0.07+0.00) 1500.3: ahead-behind counts: git branch 0.07(0.06+0.00) 1500.4: ahead-behind counts: git tag 0.07(0.06+0.00) 1500.5: ahead-behind counts: git rev-list 1.32(1.04+0.27) But the standard performance benchmark is the Linux kernel repository, which demosntrates a significant improvement: Test this tree --------------------------------------------------------------- 1500.2: ahead-behind counts: git for-each-ref 0.27(0.24+0.02) 1500.3: ahead-behind counts: git branch 0.27(0.24+0.03) 1500.4: ahead-behind counts: git tag 0.28(0.27+0.01) 1500.5: ahead-behind counts: git rev-list 4.57(4.03+0.54) The 'git rev-list' test exists in this change as a demonstration, but it will be removed in the next change to avoid wasting time on this comparison. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-18grep: correctly identify utf-8 characters with \{b,w} in -PCarlo Marcelo Arenas Belón1-0/+42
When UTF is enabled for a PCRE match, the corresponding flags are added to the pcre2_compile() call, but PCRE2_UCP wasn't included. This prevents extending the meaning of the character classes to include those new valid characters and therefore result in failed matches for expressions that rely on that extention, for ex: $ git grep -P '\bÆvar' Add PCRE2_UCP so that \w will include Æ and therefore \b could correctly match the beginning of that word. This has an impact on performance that has been estimated to be between 20% to 40% and that is shown through the added performance test. Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-10read-tree: use 'skip_cache_tree_update' optionVictoria Dye1-0/+8
When running 'read-tree' with a single tree and no prefix, 'prime_cache_tree()' is called after the tree is unpacked. In that situation, skip a redundant call to 'cache_tree_update()' in 'unpack_trees()' by enabling the 'skip_cache_tree_update' unpack option. Removing the redundant cache tree update provides a substantial performance improvement to 'git read-tree <tree-ish>', as shown by a test added to 'p0006-read-tree-checkout.sh': Test before after ---------------------------------------------------------------------- read-tree br_ballast_plus_1 3.94(1.80+1.57) 3.00(1.14+1.28) -23.9% Note that the 'read-tree' in 't1022-read-tree-partial-clone.sh' is updated to read two trees, rather than one. The test was first introduced in d3da223f221 (cache-tree: prefetch in partial clone read-tree, 2021-07-23) to exercise the 'cache_tree_update()' code path, as used in 'git merge'. Since this patch drops the call to 'cache_tree_update()' in single-tree 'git read-tree', change the test to use the two-tree variant so that 'cache_tree_update()' is called as intended. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-10reset: use 'skip_cache_tree_update' optionVictoria Dye1-0/+21
Enable the 'skip_cache_tree_update' option in the variants that call 'prime_cache_tree()' after 'unpack_trees()' (specifically, 'git reset --mixed' and 'git reset --hard'). This avoids redundantly rebuilding the cache tree in both 'cache_tree_update()' at the end of 'unpack_trees()' and in 'prime_cache_tree()', resulting in a small (but consistent) performance improvement. From the newly-added 'p7102-reset.sh' test: Test before after -------------------------------------------------------------------- 7102.1: reset --hard (...) 2.11(0.40+1.54) 1.97(0.38+1.47) -6.6% Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-10cache-tree: add perf test comparing update and primeVictoria Dye1-0/+36
Add a performance test comparing the execution times of 'prime_cache_tree()' and 'cache_tree_update(_, WRITE_TREE_SILENT | WRITE_TREE_REPAIR)'. The goal of comparing these two is to identify which is the faster method for rebuilding an invalid cache tree, ultimately to remove one when both are (reundantly) called in immediate succession. Both methods are fast, so the new tests in 'p0090-cache-tree.sh' must call each tested function multiple times to ensure the reported times (to 0.01s resolution) convey the differences between them. The tests compare the timing of a 'test-tool cache-tree' run as a no-op (to capture a baseline for the overhead associated with running the tool), 'cache_tree_update()', and 'prime_cache_tree()' on four scenarios: - A completely valid cache tree - A cache tree with 2 invalid paths - A cache tree with 50 invalid paths - A completely empty cache tree Example results: Test this tree ----------------------------------------------------------- 0090.2: no-op, clean 1.27(0.48+0.52) 0090.3: prime_cache_tree, clean 2.02(0.83+0.85) 0090.4: cache_tree_update, clean 1.30(0.49+0.54) 0090.5: no-op, invalidate 2 1.29(0.48+0.54) 0090.6: prime_cache_tree, invalidate 2 1.98(0.81+0.83) 0090.7: cache_tree_update, invalidate 2 2.12(0.94+0.86) 0090.8: no-op, invalidate 50 1.32(0.50+0.55) 0090.9: prime_cache_tree, invalidate 50 2.10(0.86+0.89) 0090.10: cache_tree_update, invalidate 50 2.35(1.14+0.90) 0090.11: no-op, empty 1.33(0.50+0.54) 0090.12: prime_cache_tree, empty 2.04(0.84+0.87) 0090.13: cache_tree_update, empty 2.51(1.27+0.92) These timings show that, while 'cache_tree_update()' is faster when the cache tree is completely valid, it is equal to or slower than 'prime_cache_tree()' when there are any invalid paths. Since the redundant calls are mostly in scenarios where the cache tree will be at least partially invalid (e.g., 'git reset --hard'), 'prime_cache_tree()' will likely perform better than 'cache_tree_update()' in typical cases. Helped-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-10-10Merge branch 'sy/sparse-grep'Junio C Hamano1-0/+1
"git grep" learned to expand the sparse-index more lazily and on demand in a sparse checkout. * sy/sparse-grep: builtin/grep.c: integrate with sparse index
2022-09-23builtin/grep.c: integrate with sparse indexShaoxuan Yuan1-0/+1
Turn on sparse index and remove ensure_full_index(). Before this patch, `git-grep` utilizes the ensure_full_index() method to expand the index and search all the entries. Because this method requires walking all the trees and constructing the index, it is the slow part within the whole command. To achieve better performance, this patch uses grep_tree() to search the sparse directory entries and get rid of the ensure_full_index() method. Why grep_tree() is a better choice over ensure_full_index()? 1) grep_tree() is as correct as ensure_full_index(). grep_tree() looks into every sparse-directory entry (represented by a tree) recursively when looping over the index, and the result of doing so matches the result of expanding the index. 2) grep_tree() utilizes pathspecs to limit the scope of searching. ensure_full_index() always expands the index, which means it will always walk all the trees and blobs in the repo without caring if the user only wants a subset of the content, i.e. using a pathspec. On the other hand, grep_tree() will only search the contents that match the pathspec, and thus possibly walking fewer trees. 3) grep_tree() does not construct and copy back a new index, while ensure_full_index() does. This also saves some time. ---------------- Performance test - Summary: p2000 tests demonstrate a ~71% execution time reduction for `git grep --cached bogus -- "f2/f1/f1/*"` using tree-walking logic. However, notice that this result varies depending on the pathspec given. See below "Command used for testing" for more details. Test HEAD~ HEAD ------------------------------------------------------- 2000.78: git grep ... (full-v3) 0.35 0.39 (≈) 2000.79: git grep ... (full-v4) 0.36 0.30 (≈) 2000.80: git grep ... (sparse-v3) 0.88 0.23 (-73.8%) 2000.81: git grep ... (sparse-v4) 0.83 0.26 (-68.6%) - Command used for testing: git grep --cached bogus -- "f2/f1/f1/*" The reason for specifying a pathspec is that, if we don't specify a pathspec, then grep_tree() will walk all the trees and blobs to find the pattern, and the time consumed doing so is not too different from using the original ensure_full_index() method, which also spends most of the time walking trees. However, when a pathspec is specified, this latest logic will only walk the area of trees enclosed by the pathspec, and the time consumed is reasonably a lot less. Generally speaking, because the performance gain is acheived by walking less trees, which are specified by the pathspec, the HEAD time v.s. HEAD~ time in sparse-v[3|4], should be proportional to "pathspec enclosed area" v.s. "all area", respectively. Namely, the wider the <pathspec> is encompassing, the less the performance difference between HEAD~ and HEAD, and vice versa. That is, if we don't specify a pathspec, the performance difference [1] is indistinguishable: both methods walk all the trees and take generally same amount of time (even with the index construction time included for ensure_full_index()). [1] Performance test result without pathspec (hence walking all trees): Command used: git grep --cached bogus Test HEAD~ HEAD --------------------------------------------------- 2000.78: git grep ... (full-v3) 6.17 5.19 (≈) 2000.79: git grep ... (full-v4) 6.19 5.46 (≈) 2000.80: git grep ... (sparse-v3) 6.57 6.44 (≈) 2000.81: git grep ... (sparse-v4) 6.65 6.28 (≈) -------------------------- NEEDSWORK about submodules There are a few NEEDSWORKs that belong to improvements beyond this topic. See the NEEDSWORK in builtin/grep.c::grep_submodule() for more context. The other two NEEDSWORKs in t1092 are also relative. Suggested-by: Derrick Stolee <derrickstolee@github.com> Helped-by: Derrick Stolee <derrickstolee@github.com> Helped-by: Victoria Dye <vdye@github.com> Helped-by: Elijah Newren <newren@gmail.com> Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-21t: convert egrep usage to "grep -E"Đoàn Trần Công Danh1-2/+2
Despite POSIX states that: > The old egrep and fgrep commands are likely to be supported for many > years to come as implementation extensions, allowing historical > applications to operate unmodified. GNU grep 3.8 started to warn[1]: > The egrep and fgrep commands, which have been deprecated since > release 2.5.3 (2007), now warn that they are obsolescent and should > be replaced by grep -E and grep -F. Prepare for their removal in the future. [1]: https://lists.gnu.org/archive/html/info-gnu/2022-09/msg00001.html Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-19Merge branch 'vd/scalar-to-main'Junio C Hamano4-1/+58
Hoist the remainder of "scalar" out of contrib/ to the main part of the codebase. * vd/scalar-to-main: Documentation/technical: include Scalar technical doc t/perf: add 'GIT_PERF_USE_SCALAR' run option t/perf: add Scalar performance tests scalar-clone: add test coverage scalar: add to 'git help -a' command list scalar: implement the `help` subcommand git help: special-case `scalar` scalar: include in standard Git build & installation scalar: fix command documentation section header
2022-09-05Merge branch 'ac/bitmap-lookup-table'Junio C Hamano5-122/+199
The pack bitmap file gained a bitmap-lookup table to speed up locating the necessary bitmap for a given commit. * ac/bitmap-lookup-table: pack-bitmap-write: drop unused pack_idx_entry parameters bitmap-lookup-table: add performance tests for lookup table pack-bitmap: prepare to read lookup table extension pack-bitmap-write: learn pack.writeBitmapLookupTable and add tests pack-bitmap-write.c: write lookup table extension bitmap: move `get commit positions` code to `bitmap_writer_finish` Documentation/technical: describe bitmap lookup table extension
2022-09-02t/perf: add 'GIT_PERF_USE_SCALAR' run optionVictoria Dye3-1/+19
Add a 'GIT_PERF_USE_SCALAR' environment variable (and corresponding perf config 'useScalar') to register a repository created with any of: * test_perf_fresh_repo * test_perf_default_repo * test_perf_large_repo as a Scalar enlistment. This is intended to allow a developer to test the impact of Scalar on already-defined performance scenarios. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02t/perf: add Scalar performance testsVictoria Dye1-0/+39
Create 'p9210-scalar.sh' for testing Scalar performance and comparing performance of Git operations in Scalar registrations and standard repositories. Example results: Test this tree ------------------------------------------------------------------------ 9210.2: scalar clone 14.82(18.00+3.63) 9210.3: git clone 26.15(36.67+6.90) 9210.4: git status (scalar) 0.04(0.01+0.01) 9210.5: git status (non-scalar) 0.10(0.02+0.11) 9210.6: test_commit --append --no-tag A (scalar) 0.08(0.02+0.03) 9210.7: test_commit --append --no-tag A (non-scalar) 0.13(0.03+0.11) Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-29Merge branch 'es/fix-chained-tests'Junio C Hamano1-1/+1
Fix broken "&&-" chains and failures in early iterations of a loop. * es/fix-chained-tests: t5329: notice a failure within a loop t: detect and signal failure within loop t1092: fix buggy sparse "blame" test t2407: fix broken &&-chains in compound statement
2022-08-29Merge branch 'vd/fix-perf-tests'Junio C Hamano2-2/+2
Rather trivial perf-test code fixes. * vd/fix-perf-tests: p0006: fix 'read-tree' argument ordering p0004: fix prereq declaration
2022-08-26bitmap-lookup-table: add performance tests for lookup tableAbhradeep Chakraborty5-122/+199
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 <me@ttaylorr.com> Co-Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com> Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-22t: detect and signal failure within loopEric Sunshine1-1/+1
Failures within `for` and `while` loops can go unnoticed if not detected and signaled manually since the loop itself does not abort when a contained command fails, nor will a failure necessarily be detected when the loop finishes since the loop returns the exit code of the last command it ran on the final iteration, which may not be the command which failed. Therefore, detect and signal failures manually within loops using the idiom `|| return 1` (or `|| exit 1` within subshells). Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19p0006: fix 'read-tree' argument orderingVictoria Dye1-1/+1
In the 'p0006' test "read-tree br_base br_ballast", move the '-n' flag used in 'git read-tree' ahead of its positional arguments. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19p0004: fix prereq declarationVictoria Dye1-1/+1
Fix multi-threaded 'p0004' test's use of the 'REPO_BIG_ENOUGH_FOR_MULTI' prerequisite. Unlike normal 't/' tests, 't/perf/' tests need to have their prerequisites declared with the '--prereq' flag. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-08rm: integrate with sparse-indexShaoxuan Yuan1-0/+1
Enable the sparse index within the `git-rm` command. The `p2000` tests demonstrate a ~92% execution time reduction for 'git rm' using a sparse index. Test HEAD~1 HEAD -------------------------------------------------------------------------- 2000.74: git rm ... (full-v3) 0.41(0.37+0.05) 0.43(0.36+0.07) +4.9% 2000.75: git rm ... (full-v4) 0.38(0.34+0.05) 0.39(0.35+0.05) +2.6% 2000.76: git rm ... (sparse-v3) 0.57(0.56+0.01) 0.05(0.05+0.00) -91.2% 2000.77: git rm ... (sparse-v4) 0.57(0.55+0.02) 0.03(0.03+0.00) -94.7% ---- Also, normalize a behavioral difference of `git-rm` under sparse-index. See related discussion [1]. `git-rm` a sparse-directory entry within a sparse-index enabled repo behaves differently from a sparse directory within a sparse-checkout enabled repo. For example, in a sparse-index repo, where 'folder1' is a sparse-directory entry, `git rm -r --sparse folder1` provides this: rm 'folder1/' Whereas in a sparse-checkout repo *without* sparse-index, doing so provides this: rm 'folder1/0/0/0' rm 'folder1/0/1' rm 'folder1/a' Because `git rm` a sparse-directory entry does not need to expand the index, therefore we should accept the current behavior, which is faster than "expand the sparse-directory entry to match the sparse-checkout situation". Modify a previous test so such difference is not considered as an error. [1] https://github.com/ffyuanda/git/pull/6#discussion_r934861398 Helped-by: Victoria Dye <vdye@github.com> Helped-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-03Merge branch 'rs/mergesort'Junio C Hamano1-2/+2
Make our mergesort implementation type-safe. * rs/mergesort: mergesort: remove llist_mergesort() packfile: use DEFINE_LIST_SORT fetch-pack: use DEFINE_LIST_SORT commit: use DEFINE_LIST_SORT blame: use DEFINE_LIST_SORT test-mergesort: use DEFINE_LIST_SORT test-mergesort: use DEFINE_LIST_SORT_DEBUG mergesort: add macros for typed sort of linked lists mergesort: tighten merge loop mergesort: unify ranks loops
2022-07-17test-mergesort: use DEFINE_LIST_SORTRené Scharfe1-2/+2
Build a typed sort function for the mergesort performance test tool using DEFINE_LIST_SORT instead of calling llist_mergesort(). This gets rid of the next pointer accessor functions and improves the performance at the cost of a slightly higher object text size. Before: 0071.12: llist_mergesort() unsorted 0.24(0.22+0.01) 0071.14: llist_mergesort() sorted 0.12(0.10+0.01) 0071.16: llist_mergesort() reversed 0.12(0.10+0.01) __TEXT __DATA __OBJC others dec hex 6407 276 0 24701 31384 7a98 t/helper/test-mergesort.o With this patch: 0071.12: DEFINE_LIST_SORT unsorted 0.22(0.21+0.01) 0071.14: DEFINE_LIST_SORT sorted 0.11(0.10+0.01) 0071.16: DEFINE_LIST_SORT reversed 0.11(0.10+0.01) __TEXT __DATA __OBJC others dec hex 6615 276 0 25832 32723 7fd3 t/helper/test-mergesort.o Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-17Merge branch 'jk/perf-lib-test-titles'Junio C Hamano1-1/+1
Show test titles to the performance test output again. * jk/perf-lib-test-titles: perf-lib: fix missing test titles in output
2022-06-16perf-lib: fix missing test titles in outputJeff King1-1/+1
Commit 5dccd9155f (t/perf: add iteration setup mechanism to perf-lib, 2022-04-04) modified the parameter parsing of test_wrapper() such that the test title was no longer in $1, and is instead in $test_title_. We correctly pass the new variable to the code which outputs the title to the log, but missed the spot in test_wrapper() where the title is written to the ".descr" file which is used to produce the final output table. As a result, all of the titles are missing from that table (or worse, using whatever was left in $1): $ ./p0000-perf-lib-sanity.sh [...] Test this tree ------------------------------ 0000.1: 0.01(0.01+0.00) 0000.2: 0.01(0.00+0.01) 0000.4: 0.00(0.00+0.00) 0000.5: true 0.00(0.00+0.00) 0000.7: 0.00(0.00+0.00) 0000.8: 0.00(0.00+0.00) After this patch, we get the pre-5dccd9155f output: Test this tree -------------------------------------------------------------------------- 0000.1: test_perf_default_repo works 0.00(0.00+0.00) 0000.2: test_checkout_worktree works 0.01(0.00+0.01) 0000.4: export a weird var 0.00(0.00+0.00) 0000.5: éḿíẗ ńöń-ÁŚĆÍÍ ćḧáŕáćẗéŕś 0.00(0.00+0.00) 0000.7: important variables available in subshells 0.00(0.00+0.00) 0000.8: test-lib-functions correctly loaded in subshells 0.00(0.00+0.00) Signed-off-by: Jeff King <peff@peff.net> Acked-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-10Merge branch 'jh/builtin-fsmonitor-part3'Junio C Hamano1-0/+257
More fsmonitor--daemon. * jh/builtin-fsmonitor-part3: (30 commits) t7527: improve implicit shutdown testing in fsmonitor--daemon fsmonitor--daemon: allow --super-prefix argument t7527: test Unicode NFC/NFD handling on MacOS t/lib-unicode-nfc-nfd: helper prereqs for testing unicode nfc/nfd t/helper/hexdump: add helper to print hexdump of stdin fsmonitor: on macOS also emit NFC spelling for NFD pathname t7527: test FSMonitor on case insensitive+preserving file system fsmonitor: never set CE_FSMONITOR_VALID on submodules t/perf/p7527: add perf test for builtin FSMonitor t7527: FSMonitor tests for directory moves fsmonitor: optimize processing of directory events fsm-listen-darwin: shutdown daemon if worktree root is moved/renamed fsm-health-win32: force shutdown daemon if worktree root moves fsm-health-win32: add polling framework to monitor daemon health fsmonitor--daemon: stub in health thread fsmonitor--daemon: rename listener thread related variables fsmonitor--daemon: prepare for adding health thread fsmonitor--daemon: cd out of worktree root fsm-listen-darwin: ignore FSEvents caused by xattr changes on macOS unpack-trees: initialize fsmonitor_has_run_once in o->result ...
2022-06-03Merge branch 'ds/sparse-sparse-checkout'Junio C Hamano1-0/+1
"sparse-checkout" learns to work well with the sparse-index feature. * ds/sparse-sparse-checkout: sparse-checkout: integrate with sparse index p2000: add test for 'git sparse-checkout [add|set]' sparse-index: complete partial expansion sparse-index: partially expand directories sparse-checkout: --no-sparse-index needs a full index cache-tree: implement cache_tree_find_path() sparse-index: introduce partially-sparse indexes sparse-index: create expand_index() t1092: stress test 'git sparse-checkout set' t1092: refactor 'sparse-index contents' test
2022-06-03Merge branch 'ns/batch-fsync'Junio C Hamano7-34/+156
Introduce a filesystem-dependent mechanism to optimize the way the bits for many loose object files are ensured to hit the disk platter. * ns/batch-fsync: core.fsyncmethod: performance tests for batch mode t/perf: add iteration setup mechanism to perf-lib core.fsyncmethod: tests for batch mode test-lib-functions: add parsing helpers for ls-files and ls-tree core.fsync: use batch mode and sync loose objects by default on Windows unpack-objects: use the bulk-checkin infrastructure update-index: use the bulk-checkin infrastructure builtin/add: add ODB transaction around add_files_to_cache cache-tree: use ODB transaction around writing a tree core.fsyncmethod: batched disk flushes for loose-objects bulk-checkin: rebrand plug/unplug APIs as 'odb transactions' bulk-checkin: rename 'state' variable and separate 'plugged' boolean
2022-05-26t/perf/p7527: add perf test for builtin FSMonitorJeff Hostetler1-0/+257
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-23p2000: add test for 'git sparse-checkout [add|set]'Derrick Stolee1-0/+1
The sparse-checkout builtin is almost completely integrated with the sparse index, allowing the sparse-checkout boundary to be modified without expanding a sparse index to a full one. Add a test to p2000-sparse-operations.sh that adds a directory to the sparse-checkout definition, then removes it. Using both operations is important to ensure that the operation is doing the same work in each repetition as well as leaving the test repo in a good state for later tests. Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-10stash: expand sparse-checkout compatibility testingVictoria Dye1-0/+2
Add tests verifying expected 'git stash' behavior in 't1092-sparse-checkout-compatibility'. These cases establish the expected behavior of 'git stash' in a sparse-checkout and verify consistency both with and without a sparse index. Although no sparse index compatibility has been integrated into 'git stash' yet, the tests are all 'expect_success' - we don't want the cone-mode sparse-checkout behavior to change depending on whether it is using a sparse index or not. Therefore, we expect these tests to continue passing once sparse index is integrated with 'git stash'. Additionally, add performance test cases for 'git stash' both with and without untracked files. Note that, unlike the other tests in 'p2000-sparse-operations.sh', the tests added for 'stash' are combination operations. This is done to ensure the stash/unstash is not blocked by the modification of '$SPARSE_CONE/a' performed as part of 'test_perf_on_all'. Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-06t/perf: add iteration setup mechanism to perf-libNeeraj Singh6-34/+74
Tests that affect the repo in stateful ways are easier to write if we can run setup steps outside of the measured portion of perf iteration. This change adds a "--setup 'setup-script'" parameter to test_perf. To make invocations easier to understand, I also moved the prerequisites to a new --prereq parameter. The setup facility will be used in the upcoming perf tests for batch mode, but it already helps in some existing tests, like t5302 and t7820. Signed-off-by: Neeraj Singh <neerajsi@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-06core.fsyncmethod: performance tests for batch modeNeeraj Singh1-0/+82
Add basic performance tests for git commands that can add data to the object database. We cover: * git add * git stash * git update-index (via git stash) * git unpack-objects * git commit --all We cover all currently available fsync methods as well. Signed-off-by: Neeraj Singh <neerajsi@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-04Merge branch 'jh/builtin-fsmonitor-part2'Junio C Hamano2-16/+54
Built-in fsmonitor (part 2). * jh/builtin-fsmonitor-part2: (30 commits) t7527: test status with untracked-cache and fsmonitor--daemon fsmonitor: force update index after large responses fsmonitor--daemon: use a cookie file to sync with file system fsmonitor--daemon: periodically truncate list of modified files t/perf/p7519: add fsmonitor--daemon test cases t/perf/p7519: speed up test on Windows t/perf/p7519: fix coding style t/helper/test-chmtime: skip directories on Windows t/perf: avoid copying builtin fsmonitor files into test repo t7527: create test for fsmonitor--daemon t/helper/fsmonitor-client: create IPC client to talk to FSMonitor Daemon help: include fsmonitor--daemon feature flag in version info fsmonitor--daemon: implement handle_client callback compat/fsmonitor/fsm-listen-darwin: implement FSEvent listener on MacOS compat/fsmonitor/fsm-listen-darwin: add MacOS header files for FSEvent compat/fsmonitor/fsm-listen-win32: implement FSMonitor backend on Windows fsmonitor--daemon: create token-based changed path cache fsmonitor--daemon: define token-ids fsmonitor--daemon: add pathname classification fsmonitor--daemon: implement 'start' command ...
2022-03-25t/perf/p7519: add fsmonitor--daemon test casesJeff Hostetler1-4/+34
Repeat all of the fsmonitor perf tests using `git fsmonitor--daemon` and the "Simple IPC" interface. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25t/perf/p7519: speed up test on WindowsJeff Hostetler1-8/+16
Change p7519 to use `test_seq` and `xargs` rather than a `for` loop to touch thousands of files. This takes minutes off of test runs on Windows because of process creation overhead. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25t/perf/p7519: fix coding styleJeff Hostetler1-4/+4
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25t/perf: avoid copying builtin fsmonitor files into test repoJeff Hostetler1-1/+1
Do not copy any of the various fsmonitor--daemon files from the .git directory of the (GIT_PREF_REPO or GIT_PERF_LARGE_REPO) source repo into the test's trash directory. When perf tests start, they copy the contents of the source repo into the test's trash directory. If fsmonitor is running in the source repo, there may be control files, such as the IPC socket and/or fsmonitor cookie files. These should not be copied into the test repo. Unix domain sockets cannot be copied in the manner used by the test setup, so if present, the test setup fails. Cookie files are harmless, but we should avoid them. The builtin fsmonitor keeps all such control files/sockets in .git/fsmonitor--daemon*, so it is simple to exclude them. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-23Merge branch 'jc/cat-file-batch-default-format-optim'Junio C Hamano1-0/+12
Optimize away strbuf_expand() call with a hardcoded formatting logic specific for the default format in the --batch and --batch-check options of "git cat-file". * jc/cat-file-batch-default-format-optim: cat-file: skip expanding default format
2022-03-16Merge branch 'vd/sparse-read-tree'Junio C Hamano1-0/+1
"git read-tree" has been made to be aware of the sparse-index feature. * vd/sparse-read-tree: read-tree: make three-way merge sparse-aware read-tree: make two-way merge sparse-aware read-tree: narrow scope of index expansion for '--prefix' read-tree: integrate with sparse index read-tree: expand sparse checkout test coverage read-tree: explicitly disallow prefixes with a leading '/' status: fix nested sparse directory diff in sparse index sparse-index: prevent repo root from becoming sparse
2022-03-15cat-file: skip expanding default formatJohn Cai1-0/+12
When format is passed into --batch, --batch-check, --batch-command, the format gets expanded. When nothing is passed in, the default format is set and the expand_format() gets called. We can save on these cycles by hardcoding how to print the information when nothing is passed as the format, or when the default format is passed. There is no need for the fully expanded format with the default. Since batch_object_write() happens on every object provided in batch mode, we get a nice performance improvement. git rev-list --all > /tmp/all-obj.txt git cat-file --batch-check </tmp/all-obj.txt with HEAD^: Time (mean ± σ): 57.6 ms ± 1.7 ms [User: 51.5 ms, System: 6.2 ms] Range (min … max): 54.6 ms … 64.7 ms 50 runs with HEAD: Time (mean ± σ): 49.8 ms ± 1.7 ms [User: 42.6 ms, System: 7.3 ms] Range (min … max): 46.9 ms … 55.9 ms 56 runs If nothing is provided as a format argument, or if the default format is passed, skip expanding of the format and print the object info with a default format. See https://lore.kernel.org/git/87eecf8ork.fsf@evledraar.gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: John Cai <johncai86@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to itÆvar Arnfjörð Bjarmason1-0/+3
We have various behavior that's shared across our Makefiles, or that really should be (e.g. via defined templates). Let's create a top-level "shared.mak" to house those sorts of things, and start by adding the ".DELETE_ON_ERROR" flag to it. See my own 7b76d6bf221 (Makefile: add and use the ".DELETE_ON_ERROR" flag, 2021-06-29) and db10fc6c09f (doc: simplify Makefile using .DELETE_ON_ERROR, 2021-05-21) for the addition and use of the ".DELETE_ON_ERROR" flag. I.e. this changes the behavior of existing rules in the altered Makefiles (except "Makefile" & "Documentation/Makefile"). I'm confident that this is safe having read the relevant rules in those Makfiles, and as the GNU make manual notes that it isn't the default behavior is out of an abundance of backwards compatibility caution. From edition 0.75 of its manual, covering GNU make 4.3: [Enabling '.DELETE_ON_ERROR' is] almost always what you want 'make' to do, but it is not historical practice; so for compatibility, you must explicitly request it. This doesn't introduce a bug by e.g. having this ".DELETE_ON_ERROR" flag only apply to this new shared.mak, Makefiles have no such scoping semantics. It does increase the danger that any Makefile without an explicit "The default target of this Makefile is..." snippet to define the default target as "all" could have its default rule changed if our new shared.mak ever defines a "real" rule. In subsequent commits we'll be careful not to do that, and such breakage would be obvious e.g. in the case of "make -C t". We might want to make that less fragile still (e.g. by using ".DEFAULT_GOAL" as noted in the preceding commit), but for now let's simply include "shared.mak" without adding that boilerplate to all the Makefiles that don't have it already. Most of those are already exposed to that potential caveat e.g. due to including "config.mak*". Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01read-tree: expand sparse checkout test coverageVictoria Dye1-0/+1
Add tests focused on how 'git read-tree' behaves in sparse checkouts. Extra emphasis is placed on interactions with files outside the sparse cone, e.g. merges with out-of-cone conflicts. Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-17Merge branch 'vd/sparse-clean-etc'Junio C Hamano1-0/+2
"git update-index", "git checkout-index", and "git clean" are taught to work better with the sparse checkout feature. * vd/sparse-clean-etc: update-index: reduce scope of index expansion in do_reupdate update-index: integrate with sparse index update-index: add tests for sparse-checkout compatibility checkout-index: integrate with sparse index checkout-index: add --ignore-skip-worktree-bits option checkout-index: expand sparse checkout compatibility tests clean: integrate with sparse index reset: reorder wildcard pathspec conditions reset: fix validation in sparse index test
2022-01-13update-index: add tests for sparse-checkout compatibilityVictoria Dye1-0/+1
Introduce tests for a variety of `git update-index` use cases, including performance scenarios. Tests are intended to exercise `update-index` with options that change the commands interaction with the index (e.g., `--again`) and with files/directories inside and outside a sparse checkout cone. Of note is that these tests clearly establish the behavior of `git update-index --add` with untracked, outside-of-cone files. Unlike `git add`, which fails with an error when provided with such files, `update-index` succeeds in adding them to the index. Additionally, the `skip-worktree` flag is *not* automatically added to the new entry. Although this is pre-existing behavior, there are a couple of reasons to avoid changing it in favor of consistency with e.g. `git add`: * `update-index` is low-level command for modifying the index; while it can perform operations similar to those of `add`, it traditionally has fewer "guardrails" preventing a user from doing something they may not want to do (in this case, adding an outside-of-cone, non-`skip-worktree` file to the index) * `update-index` typically only exits with an error code if it is incapable of performing an operation (e.g., if an internal function call fails); adding a new file outside the sparse checkout definition is still a valid operation, albeit an inadvisable one * `update-index` does not implicitly set flags (e.g., `skip-worktree`) when creating new index entries with `--add`; if flags need to be updated, options like `--[no-]skip-worktree` allow a user to intentionally set them All this to say that, while there are valid reasons to consider changing the treatment of outside-of-cone files in `update-index`, there are also sufficient reasons for leaving it as-is. Co-authored-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-13checkout-index: expand sparse checkout compatibility testsVictoria Dye1-0/+1
Add tests to cover `checkout-index`, with a focus on cases interesting in a sparse checkout (e.g., files specified outside sparse checkout definition). New tests are intended to serve as a baseline for existing and/or expected behavior and performance when integrating `checkout-index` with the sparse index. Note that the test 'checkout-index --all' is marked as 'test_expect_failure', indicating that `update-index --all` will be modified in a subsequent patch to behave as the test expects. Signed-off-by: Victoria Dye <vdye@github.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-10Merge branch 'ja/perf-use-specified-shell'Junio C Hamano1-1/+1
Perf tests were run with end-user's shell, but it has been corrected to use the shell specified by $TEST_SHELL_PATH. * ja/perf-use-specified-shell: t/perf: do not run tests in user's $SHELL
2022-01-05Merge branch 'pw/diff-color-moved-fix'Junio C Hamano1-0/+57
Correctness and performance update to "diff --color-moved" feature. * pw/diff-color-moved-fix: diff --color-moved: intern strings diff: use designated initializers for emitted_diff_symbol diff --color-moved-ws=allow-indentation-change: improve hash lookups diff --color-moved: stop clearing potential moved blocks diff --color-moved: shrink potential moved blocks as we go diff --color-moved: unify moved block growth functions diff --color-moved: call comparison function directly diff --color-moved-ws=allow-indentation-change: simplify and optimize diff: simplify allow-indentation-change delta calculation diff --color-moved: avoid false short line matches and bad zebra coloring diff --color-moved=zebra: fix alternate coloring diff --color-moved: rewind when discarding pmb diff --color-moved: factor out function diff --color-moved: clear all flags on blocks that are too short diff --color-moved: add perf tests
2022-01-03Merge branch 'es/test-chain-lint'Junio C Hamano10-35/+35
Broken &&-chains in the test scripts have been corrected. * es/test-chain-lint: t6000-t9999: detect and signal failure within loop t5000-t5999: detect and signal failure within loop t4000-t4999: detect and signal failure within loop t0000-t3999: detect and signal failure within loop tests: simplify by dropping unnecessary `for` loops tests: apply modern idiom for exiting loop upon failure tests: apply modern idiom for signaling test failure tests: fix broken &&-chains in `{...}` groups tests: fix broken &&-chains in `$(...)` command substitutions tests: fix broken &&-chains in compound statements tests: use test_write_lines() to generate line-oriented output tests: simplify construction of large blocks of text t9107: use shell parameter expansion to avoid breaking &&-chain t6300: make `%(raw:size) --shell` test more robust t5516: drop unnecessary subshell and command invocation t4202: clarify intent by creating expected content less cleverly t1020: avoid aborting entire test script when one test fails t1010: fix unnoticed failure on Windows t/lib-pager: use sane_unset() to avoid breaking &&-chain
2021-12-25t/perf: do not run tests in user's $SHELLJohannes Altmanninger1-1/+1
The environment variable $SHELL is usually set to the user's interactive shell. Our build and test scripts never use $SHELL because there are no guarantees about its input language. Instead, we use /bin/sh which should be a POSIX shell. For systems with a broken /bin/sh, we allow to override that path via SHELL_PATH. To run tests in yet another shell we allow to override SHELL_PATH with TEST_SHELL_PATH. Perf tests run in $SHELL via a wrapper defined in t/perf/perf-lib.sh, so they break with e.g. SHELL=python. Use TEST_SHELL_PATH like in other tests. TEST_SHELL_PATH is always defined because t/perf/perf-lib.sh includes t/test-lib.sh, which includes GIT-BUILD-OPTIONS. Acked-by: Jeff King <peff@peff.net> Signed-off-by: Johannes Altmanninger <aclopte@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-21Merge branch 'ld/sparse-diff-blame'Junio C Hamano1-0/+4
Teach diff and blame to work well with sparse index. * ld/sparse-diff-blame: blame: enable and test the sparse index diff: enable and test the sparse index diff: replace --staged with --cached in t1092 tests repo-settings: prepare_repo_settings only in git repos test-read-cache: set up repo after git directory commit-graph: return if there is no git directory git: ensure correct git directory setup with -h
2021-12-13t0000-t3999: detect and signal failure within loopEric Sunshine7-12/+12
Failures within `for` and `while` loops can go unnoticed if not detected and signaled manually since the loop itself does not abort when a contained command fails, nor will a failure necessarily be detected when the loop finishes since the loop returns the exit code of the last command it ran on the final iteration, which may not be the command which failed. Therefore, detect and signal failures manually within loops using the idiom `|| return 1` (or `|| exit 1` within subshells). Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13tests: fix broken &&-chains in compound statementsEric Sunshine5-23/+23
The top-level &&-chain checker built into t/test-lib.sh causes tests to magically exit with code 117 if the &&-chain is broken. However, it has the shortcoming that the magic does not work within `{...}` groups, `(...)` subshells, `$(...)` substitutions, or within bodies of compound statements, such as `if`, `for`, `while`, `case`, etc. `chainlint.sed` partly fills in the gap by catching broken &&-chains in `(...)` subshells, but bugs can still lurk behind broken &&-chains in the other cases. Fix broken &&-chains in compound statements in order to reduce the number of possible lurking bugs. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-10Merge branch 'vd/sparse-reset'Junio C Hamano1-0/+3
Various operating modes of "git reset" have been made to work better with the sparse index. * vd/sparse-reset: unpack-trees: improve performance of next_cache_entry reset: make --mixed sparse-aware reset: make sparse-aware (except --mixed) reset: integrate with sparse index reset: expand test coverage for sparse checkouts sparse-index: update command for expand/collapse test reset: preserve skip-worktree bit in mixed reset reset: rename is_missing to !is_in_reset_tree
2021-12-09diff --color-moved: add perf testsPhillip Wood1-0/+57
Add some tests so we can monitor changes to the performance of the move detection code. The tests record the performance --color-moved and --color-moved-ws=allow-indentation-change for a large diff and a sequence of smaller diffs. The range of commits used for the large diff can be customized by exporting TEST_REV_A and TEST_REV_B when running the test. Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06blame: enable and test the sparse indexLessley Dennington1-0/+2
Enable the sparse index for the 'git blame' command. The index was already not expanded with this command, so the most interesting thing to do is to add tests that verify that 'git blame' behaves correctly when the sparse index is enabled and that its performance improves. More specifically, these cases are: 1. The index is not expanded for 'blame' when given paths in the sparse checkout cone at multiple levels. 2. Performance measurably improves for 'blame' with sparse index when given paths in the sparse checkout cone at multiple levels. The `p2000` tests demonstrate a ~60% execution time reduction when running 'blame' for a file two levels deep and and a ~30% execution time reduction for a file three levels deep. Test before after ---------------------------------------------------------------- 2000.62: git blame f2/f4/a (full-v3) 0.31 0.32 +3.2% 2000.63: git blame f2/f4/a (full-v4) 0.29 0.31 +6.9% 2000.64: git blame f2/f4/a (sparse-v3) 0.55 0.23 -58.2% 2000.65: git blame f2/f4/a (sparse-v4) 0.57 0.23 -59.6% 2000.66: git blame f2/f4/f3/a (full-v3) 0.77 0.85 +10.4% 2000.67: git blame f2/f4/f3/a (full-v4) 0.78 0.81 +3.8% 2000.68: git blame f2/f4/f3/a (sparse-v3) 1.07 0.72 -32.7% 2000.99: git blame f2/f4/f3/a (sparse-v4) 1.05 0.73 -30.5% We do not include paths outside the sparse checkout cone because blame does not support blaming files that are not present in the working directory. This is true in both sparse and full checkouts. Signed-off-by: Lessley Dennington <lessleydennington@gmail.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06diff: enable and test the sparse indexLessley Dennington1-0/+2
Enable the sparse index within the 'git diff' command. Its implementation already safely integrates with the sparse index because it shares code with the 'git status' and 'git checkout' commands that were already integrated. For more details see: d76723ee53 (status: use sparse-index throughout, 2021-07-14) 1ba5f45132 (checkout: stop expanding sparse indexes, 2021-06-29) The most interesting thing to do is to add tests that verify that 'git diff' behaves correctly when the sparse index is enabled. These cases are: 1. The index is not expanded for 'diff' and 'diff --staged' 2. 'diff' and 'diff --staged' behave the same in full checkout, sparse checkout, and sparse index repositories in the following partially-staged scenarios (i.e. the index, HEAD, and working directory differ at a given path): 1. Path is within sparse-checkout cone 2. Path is outside sparse-checkout cone 3. A merge conflict exists for paths outside sparse-checkout cone The `p2000` tests demonstrate a ~44% execution time reduction for 'git diff' and a ~86% execution time reduction for 'git diff --staged' using a sparse index: Test before after ------------------------------------------------------------- 2000.30: git diff (full-v3) 0.33 0.34 +3.0% 2000.31: git diff (full-v4) 0.33 0.35 +6.1% 2000.32: git diff (sparse-v3) 0.53 0.31 -41.5% 2000.33: git diff (sparse-v4) 0.54 0.29 -46.3% 2000.34: git diff --cached (full-v3) 0.07 0.07 +0.0% 2000.35: git diff --cached (full-v4) 0.07 0.08 +14.3% 2000.36: git diff --cached (sparse-v3) 0.28 0.04 -85.7% 2000.37: git diff --cached (sparse-v4) 0.23 0.03 -87.0% Co-authored-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Lessley Dennington <lessleydennington@gmail.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-29Merge branch 'vd/sparse-reset' into ld/sparse-diff-blameJunio C Hamano1-0/+3
* vd/sparse-reset: unpack-trees: improve performance of next_cache_entry reset: make --mixed sparse-aware reset: make sparse-aware (except --mixed) reset: integrate with sparse index reset: expand test coverage for sparse checkouts sparse-index: update command for expand/collapse test reset: preserve skip-worktree bit in mixed reset reset: rename is_missing to !is_in_reset_tree
2021-11-29reset: expand test coverage for sparse checkoutsVictoria Dye1-0/+3
Add new tests for `--merge` and `--keep` modes, as well as mixed reset with pathspecs. New performance test cases exercise various execution paths for `reset`. Co-authored-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-25Merge branch 'rs/disable-gc-during-perf-tests'Junio C Hamano2-0/+6
Avoid performance measurements from getting ruined by gc and other housekeeping pauses interfering in the middle. * rs/disable-gc-during-perf-tests: perf: disable automatic housekeeping
2021-10-25Merge branch 'jh/perf-remove-test-times'Junio C Hamano1-0/+1
Perf test fix. * jh/perf-remove-test-times: t/perf/perf-lib.sh: remove test_times.* at the end test_perf_()
2021-10-18Merge branch 'rs/mergesort'Junio C Hamano1-7/+33
The mergesort implementation used to sort linked list has been optimized. * rs/mergesort: test-mergesort: use repeatable random numbers mergesort: use ranks stack p0071: test performance of llist_mergesort() p0071: measure sorting of already sorted and reversed files test-mergesort: add unriffle_skewed mode test-mergesort: add unriffle mode test-mergesort: add generate subcommand test-mergesort: add test subcommand test-mergesort: add sort subcommand test-mergesort: use strbuf_getline()
2021-10-11perf: disable automatic housekeepingRené Scharfe2-0/+6
Turn off automatic background maintenance for perf tests by default to avoid interference with performance measurements. Do that by using the new file t/perf/config and using it as the system config file for perf tests. Future tests intended to measure gc performance can override the setting locally or call "git gc" explicitly. This fixes a breakage in p2000 caused by gc automatically emptying the reflog due its fake dates from 2005 being older than 90 days. Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-11Merge branch 'tb/aggregate-ignore-leading-whitespaces'Junio C Hamano1-2/+2
Test portability update. * tb/aggregate-ignore-leading-whitespaces: t/perf/aggregate.perl: tolerate leading spaces
2021-10-11Merge branch 'rs/p3400-lose-tac'Junio C Hamano1-1/+1
Test portability update. * rs/p3400-lose-tac: p3400: stop using tac(1)
2021-10-11Merge branch 'tb/midx-write-propagate-namehash'Junio C Hamano1-3/+12
"git multi-pack-index write --bitmap" learns to propagate the hashcache from original bitmap to resulting bitmap. * tb/midx-write-propagate-namehash: t5326: test propagating hashcache values p5326: generate pack bitmaps before writing the MIDX bitmap p5326: don't set core.multiPackIndex unnecessarily p5326: create missing 'perf-tag' tag midx.c: respect 'pack.writeBitmapHashcache' when writing bitmaps pack-bitmap.c: propagate namehash values from existing bitmaps t/helper/test-bitmap.c: add 'dump-hashes' mode
2021-10-04t/perf/perf-lib.sh: remove test_times.* at the end test_perf_()Jeff Hostetler1-0/+1
Teach test_perf_() to remove the temporary test_times.* files at the end of each test. test_perf_() runs a particular GIT_PERF_REPEAT_COUNT times and creates ./test_times.[123...]. It then uses a perl script to find the minimum over "./test_times.*" (note the wildcard) and writes that time to "test-results/<testname>.<testnumber>.result". If the repeat count is changed during the pXXXX test script, stale test_times.* files (from previous steps) may be included in the min() computation. For example: ... GIT_PERF_REPEAT_COUNT=3 \ test_perf "status" " git status " GIT_PERF_REPEAT_COUNT=1 \ test_perf "checkout other" " git checkout other " ... The time reported in the summary for "XXXX.2 checkout other" would be "min( checkout[1], status[2], status[3] )". We prevent that error by removing the test_times.* files at the end of each test. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-04t/perf/aggregate.perl: tolerate leading spacesTaylor Blau1-2/+2
When using `test_size` with `wc -c`, users on certain platforms can run into issues when `wc` emits leading space characters in its output, which confuses get_times. Callers could switch to use test_file_size instead of `wc -c` (the former never prints leading space characters, so will always work with test_size regardless of platform), but this is an easy enough spot to miss that we should teach get_times to be more tolerant of the input it accepts. Teach get_times to do just that by stripping any leading space characters. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-03p3400: stop using tac(1)René Scharfe1-1/+1
b3dfeebb92 (rebase: avoid computing unnecessary patch IDs, 2016-07-29) added a perf test that calls tac(1) from GNU core utilities. Support systems without it by reversing the generated list using sort -nr instead. sort(1) with options -n and -r is already used in other tests. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01p0071: test performance of llist_mergesort()René Scharfe1-0/+11
Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-01p0071: measure sorting of already sorted and reversed filesRené Scharfe1-7/+22
Check if sorting takes advantage of already sorted or reversed content, or if that corner case actually decreases performance, like it would for a simplistic quicksort implementation. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-22t/perf/run: fix bin-wrappers computationDerrick Stolee1-1/+1
The GIT_TEST_INSTALLED was moved from perf-lib.sh to run in df0f5021 (perf-lib.sh: remove GIT_TEST_INSTALLED from perf-lib.sh, 2019-05-07) and that included a change to how it inspected the existence of a bin-wrappers directory. However, that included a typo that made the match of bin-wrappers never work. Specifically, the assignment was mydir_abs_wrappers="$mydir_abs_wrappers/bin-wrappers" which uses the same variable before it is initialized. By changing it to mydir_abs_wrappers="$mydir_abs/bin-wrappers" We can correctly use the bin-wrappers directory. This is critical to successfully computing performance of commands that execute subcommands. The bin-wrappers ensure that the --exec-path is set correctly. Reported-by: Victoria Dye <vdye@github.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-17p5326: generate pack bitmaps before writing the MIDX bitmapTaylor Blau1-1/+8
To help test the performance of permuting the contents of the hash-cache when generating a MIDX bitmap, we need a bitmap which has its hash-cache populated. And since multi-pack bitmaps don't add *new* values to the hash-cache, we have to rely on a single-pack bitmap to generate those values for us. Therefore, generate a pack bitmap before the MIDX one in order to ensure that the MIDX bitmap has entries in its hash-cache. Since we don't want to time generating the pack bitmap, move that to a non-perf test run before we try to generate the MIDX bitmap. Likewise, get rid of the pack bitmap afterwords, to make certain that we are not accidentally using it in the performance tests run later on. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14p5326: don't set core.multiPackIndex unnecessarilyTaylor Blau1-4/+0
When this performance test was originally written, `core.multiPackIndex` was not the default and thus had to be enabled. But now that we have 18e449f86b (midx: enable core.multiPackIndex by default, 2020-09-25), we no longer need this. Drop the unnecessary setup (even though it's not hurting anything, it is unnecessary at best and confusing at worst). Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14p5326: create missing 'perf-tag' tagTaylor Blau1-0/+6
Some of the tests in test_full_bitmap rely on having a tag named perf-tag in place. We could create it in test_full_bitmap(), but we want to have it in place before the repack starts. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01p5326: perf tests for MIDX bitmapsTaylor Blau1-0/+43
These new performance tests demonstrate effectively the same behavior as p5310, but use a multi-pack bitmap instead of a single-pack one. Notably, p5326 does not create a MIDX bitmap with multiple packs. This is so we can measure a direct comparison between it and p5310. Any difference between the two is measuring just the overhead of using MIDX bitmaps. Here are the results of p5310 and p5326 together, measured at the same time and on the same machine (using a Xenon W-2255 CPU): Test HEAD ------------------------------------------------------------------------ 5310.2: repack to disk 96.78(93.39+11.33) 5310.3: simulated clone 9.98(9.79+0.19) 5310.4: simulated fetch 1.75(4.26+0.19) 5310.5: pack to file (bitmap) 28.20(27.87+8.70) 5310.6: rev-list (commits) 0.41(0.36+0.05) 5310.7: rev-list (objects) 1.61(1.54+0.07) 5310.8: rev-list count with blob:none 0.25(0.21+0.04) 5310.9: rev-list count with blob:limit=1k 2.65(2.54+0.10) 5310.10: rev-list count with tree:0 0.23(0.19+0.04) 5310.11: simulated partial clone 4.34(4.21+0.12) 5310.13: clone (partial bitmap) 11.05(12.21+0.48) 5310.14: pack to file (partial bitmap) 31.25(34.22+3.70) 5310.15: rev-list with tree filter (partial bitmap) 0.26(0.22+0.04) versus the same tests (this time using a multi-pack index): Test HEAD ------------------------------------------------------------------------ 5326.2: setup multi-pack index 78.99(75.29+11.58) 5326.3: simulated clone 11.78(11.56+0.22) 5326.4: simulated fetch 1.70(4.49+0.13) 5326.5: pack to file (bitmap) 28.02(27.72+8.76) 5326.6: rev-list (commits) 0.42(0.36+0.06) 5326.7: rev-list (objects) 1.65(1.58+0.06) 5326.8: rev-list count with blob:none 0.26(0.21+0.05) 5326.9: rev-list count with blob:limit=1k 2.97(2.86+0.10) 5326.10: rev-list count with tree:0 0.25(0.20+0.04) 5326.11: simulated partial clone 5.65(5.49+0.16) 5326.13: clone (partial bitmap) 12.22(13.43+0.38) 5326.14: pack to file (partial bitmap) 30.05(31.57+7.25) 5326.15: rev-list with tree filter (partial bitmap) 0.24(0.20+0.04) There is slight overhead in "simulated clone", "simulated partial clone", and "clone (partial bitmap)". Unsurprisingly, that overhead is due to using the MIDX's reverse index to map between bit positions and MIDX positions. This can be reproduced by running "git repack -adb" along with "git multi-pack-index write --bitmap" in a large-ish repository. Then run: $ perf record -o pack.perf git -c core.multiPackIndex=false \ pack-objects --all --stdout >/dev/null </dev/null $ perf record -o midx.perf git -c core.multiPackIndex=true \ pack-objects --all --stdout >/dev/null </dev/null and compare the two with "perf diff -c delta -o 1 pack.perf midx.perf". The most notable results are below (the next largest positive delta is +0.14%): # Event 'cycles' # # Baseline Delta Shared Object Symbol # ........ ....... .................. .......................... # +5.86% git [.] nth_midxed_offset +5.24% git [.] nth_midxed_pack_int_id 3.45% +0.97% git [.] offset_to_pack_pos 3.30% +0.57% git [.] pack_pos_to_offset +0.30% git [.] pack_pos_to_midx Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-01p5310: extract full and partial bitmap testsTaylor Blau2-62/+72
A new p5326 introduced by the next patch will want these same tests, interjecting its own setup in between. Move them out so that both perf tests can reuse them. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-04Merge branch 'ds/commit-and-checkout-with-sparse-index'Junio C Hamano1-17/+30
"git checkout" and "git commit" learn to work without unnecessarily expanding sparse indexes. * ds/commit-and-checkout-with-sparse-index: unpack-trees: resolve sparse-directory/file conflicts t1092: document bad 'git checkout' behavior checkout: stop expanding sparse indexes sparse-index: recompute cache-tree commit: integrate with sparse-index p2000: compress repo names p2000: add 'git checkout -' test and decrease depth
2021-08-02Merge branch 'ps/perf-with-separate-output-directory'Junio C Hamano3-13/+24
Test update. * ps/perf-with-separate-output-directory: perf: fix when running with TEST_OUTPUT_DIRECTORY
2021-07-14p2000: compress repo namesDerrick Stolee1-10/+10
By using shorter names for the test repos, we will get a slightly more compressed performance summary without comprimising clarity. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-14p2000: add 'git checkout -' test and decrease depthDerrick Stolee1-7/+20
As we increase our list of commands to test in p2000-sparse-operations.sh, we will want to have a slightly smaller test repository. Reduce the size by a factor of four by reducing the depth of the step that creates a big index around a moderately-sized repository. Also add a step to run 'git checkout -' on repeat. This requires having a previous location in the reflog, so add that to the initialization steps. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-13Merge branch 'ab/pickaxe-pcre2'Junio C Hamano1-0/+70
Rewrite the backend for "diff -G/-S" to use pcre2 engine when available. * ab/pickaxe-pcre2: (22 commits) xdiff-interface: replace discard_hunk_line() with a flag xdiff users: use designated initializers for out_line pickaxe -G: don't special-case create/delete pickaxe -G: terminate early on matching lines xdiff-interface: allow early return from xdiff_emit_line_fn xdiff-interface: prepare for allowing early return pickaxe -S: slightly optimize contains() pickaxe: rename variables in has_changes() for brevity pickaxe -S: support content with NULs under --pickaxe-regex pickaxe: assert that we must have a needle under -G or -S pickaxe: refactor function selection in diffcore-pickaxe() perf: add performance test for pickaxe pickaxe/style: consolidate declarations and assignments diff.h: move pickaxe fields together again pickaxe: die when --find-object and --pickaxe-all are combined pickaxe: die when -G and --pickaxe-regex are combined pickaxe tests: add missing test for --no-pickaxe-regex being an error pickaxe tests: test for -G, -S and --find-object incompatibility pickaxe tests: add test for "log -S" not being a regex pickaxe tests: add test for diffgrep_consume() internals ...
2021-07-02perf: fix when running with TEST_OUTPUT_DIRECTORYPatrick Steinhardt3-13/+24
When the TEST_OUTPUT_DIRECTORY is defined, then all test data will be written in that directory instead of the default directory located in "t/". While this works as expected for our normal tests, performance tests fail to locate and aggregate performance data because they don't know to handle TEST_OUTPUT_DIRECTORY correctly and always look at the default location. Fix the issue by adding a `--results-dir` parameter to "aggregate.perl" which identifies the directory where results are and by making the "run" script awake of the TEST_OUTPUT_DIRECTORY variable. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-11perf: add performance test for pickaxeÆvar Arnfjörð Bjarmason1-0/+70
Add a test for the -G and -S pickaxe options and related options. This test supports being run with GIT_TEST_LONG=1 to adjust the limit on the number of commits from 1k to 10k. The 1k limit seems to hit a good spot on git.git Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-10Merge branch 'rs/repack-without-loosening-promised-objects'Junio C Hamano1-0/+4
"git repack -A -d" in a partial clone unnecessarily loosened objects in promisor pack. * rs/repack-without-loosening-promised-objects: repack: avoid loosening promisor objects in partial clones
2021-04-30Merge branch 'ds/sparse-index-protections'Junio C Hamano1-0/+101
Builds on top of the sparse-index infrastructure to mark operations that are not ready to mark with the sparse index, causing them to fall back on fully-populated index that they always have worked with. * ds/sparse-index-protections: (47 commits) name-hash: use expand_to_path() sparse-index: expand_to_path() name-hash: don't add directories to name_hash revision: ensure full index resolve-undo: ensure full index read-cache: ensure full index pathspec: ensure full index merge-recursive: ensure full index entry: ensure full index dir: ensure full index update-index: ensure full index stash: ensure full index rm: ensure full index merge-index: ensure full index ls-files: ensure full index grep: ensure full index fsck: ensure full index difftool: ensure full index commit: ensure full index checkout: ensure full index ...
2021-04-28repack: avoid loosening promisor objects in partial clonesRafael Silva1-0/+4
When `git repack -A -d` is run in a partial clone, `pack-objects` is invoked twice: once to repack all promisor objects, and once to repack all non-promisor objects. The latter `pack-objects` invocation is with --exclude-promisor-objects and --unpack-unreachable, which loosens all objects unused during this invocation. Unfortunately, this includes promisor objects. Because the -d argument to `git repack` subsequently deletes all loose objects also in packs, these just-loosened promisor objects will be immediately deleted. However, this extra disk churn is unnecessary in the first place. For example, in a newly-cloned partial repo that filters all blob objects (e.g. `--filter=blob:none`), `repack` ends up unpacking all trees and commits into the filesystem because every object, in this particular case, is a promisor object. Depending on the repo size, this increases the disk usage considerably: In my copy of the linux.git, the object directory peaked 26GB of more disk usage. In order to avoid this extra disk churn, pass the names of the promisor packfiles as --keep-pack arguments to the second invocation of `pack-objects`. This informs `pack-objects` that the promisor objects are already in a safe packfile and, therefore, do not need to be loosened. For testing, we need to validate whether any object was loosened. However, the "evidence" (loosened objects) is deleted during the process which prevents us from inspecting the object directory. Instead, let's teach `pack-objects` to count loosened objects and emit via trace2 thus allowing inspecting the debug events after the process is finished. This new event is used on the added regression test. Lastly, add a new perf test to evaluate the performance impact made by this changes (tested on git.git): Test HEAD^ HEAD ---------------------------------------------------------- 5600.3: gc 134.38(41.93+90.95) 7.80(6.72+1.35) -94.2% For a bigger repository, such as linux.git, the improvement is even bigger: Test HEAD^ HEAD ------------------------------------------------------------------- 5600.3: gc 6833.00(918.07+3162.74) 268.79(227.02+39.18) -96.1% These improvements are particular big because every object in the newly-cloned partial repository is a promisor object. Reported-by: SZEDER Gábor <szeder.dev@gmail.com> Helped-by: Jeff King <peff@peff.net> Helped-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13revision: avoid parsing with --exclude-promisor-objectsJeff King1-0/+8
When --exclude-promisor-objects is given, before traversing any objects we iterate over all of the objects in any promisor packs, marking them as UNINTERESTING and SEEN. We turn the oid we get from iterating the pack into an object with parse_object(), but this has two problems: - it's slow; we are zlib inflating (and reconstructing from deltas) every byte of every object in the packfile - it leaves the tree buffers attached to their structs, which means our heap usage will grow to store every uncompressed tree simultaneously. This can be gigabytes. We can obviously fix the second by freeing the tree buffers after we've parsed them. But we can observe that the function doesn't look at the object contents at all! The only reason we call parse_object() is that we need a "struct object" on which to set the flags. There are two options here: - we can look up just the object type via oid_object_info(), and then call the appropriate lookup_foo() function - we can call lookup_unknown_object(), which gives us an OBJ_NONE struct (which will get auto-converted later by object_as_type() via calls to lookup_commit(), etc). The first one is closer to the current code, but we do pay the price to look up the type for each object. The latter should be more efficient in CPU, though it wastes a little bit of memory (the "unknown" object structs are a union of all object types, so some of the structs are bigger than they need to be). It also runs the risk of triggering a latent bug in code that calls lookup_object() directly but isn't ready to handle OBJ_NONE (such code would already be buggy, but we use lookup_unknown_object() infrequently enough that it might be hiding). I went with the second option here. I don't think the risk is high (and we'd want to find and fix any such bugs anyway), and it should be more efficient overall. The new tests in p5600 show off the improvement (this is on git.git): Test HEAD^ HEAD ------------------------------------------------------------------------------- 5600.5: count commits 0.37(0.37+0.00) 0.38(0.38+0.00) +2.7% 5600.6: count non-promisor commits 11.74(11.37+0.37) 0.04(0.03+0.00) -99.7% The improvement is particularly big in this script because _every_ object in the newly-cloned partial repo is a promisor object. So after marking them all, there's nothing left to traverse. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13is_promisor_object(): free tree buffer after parsingJeff King1-0/+4
To get the list of all promisor objects, we not only include all objects in promisor packs, but also parse each of those objects to see which objects they reference. After parsing a tree object, the tree->buffer field will remain populated until we explicitly free it. So in a partial clone of blob:none, for example, we are essentially reading every tree in the repository (since they're all in the initial promisor pack), and keeping all of their uncompressed contents in memory at once. This patch frees the tree buffers after we've finished marking all of their reachable objects. We shouldn't need to do this for any other object type. While we are using some extra memory to store the structs, no other object type stores the whole contents in its parsed form (we do sometimes hold on to commit buffers, but less so these days due to commit graphs, plus most commands which care about promisor objects turn off the save_commit_buffer global). Even for a moderate-sized repository like git.git, this patch drops the peak heap (as measured by massif) for git-fsck from ~1.7GB to ~138MB. Fsck is a good candidate for measuring here because it doesn't interact with the promisor code except to call is_promisor_object(), so we can isolate just this problem. The added perf test shows only a tiny improvement on my machine for git.git, since 1.7GB isn't enough to cause any real memory pressure: Test HEAD^ HEAD -------------------------------------------------------------------------------- 5600.4: fsck 21.26(20.90+0.35) 20.84(20.79+0.04) -2.0% With linux.git the absolute change is a bit bigger, though still a small percentage: Test HEAD^ HEAD ----------------------------------------------------------------------------- 5600.4: fsck 262.26(259.13+3.12) 254.92(254.62+0.29) -2.8% I didn't have the patience to run it under massif with linux.git, but it's probably on the order of about 14GB improvement, since that's the sum of the sizes of all of the uncompressed trees (but still isn't enough to create memory pressure on this particular machine, which has 64GB of RAM). Smaller machines would probably see a bigger effect on runtime (and sadly our perf suite does not measure peak heap). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-07Merge branch 'ps/pack-bitmap-optim'Junio C Hamano1-0/+14
Optimize "rev-list --use-bitmap-index --objects" corner case that uses negative tags as the stopping points. * ps/pack-bitmap-optim: pack-bitmap: avoid traversal of objects referenced by uninteresting tag
2021-03-30p2000: add sparse-index reposDerrick Stolee1-1/+18
p2000-sparse-operations.sh compares different Git commands in repositories with many files at HEAD but using sparse-checkout to focus on a small portion of those files. Add extra copies of the repository that use the sparse-index format so we can track how that affects the performance of different commands. At this point in time, the sparse-index is 100% overhead from the CPU front, and this is measurable in these tests: Test --------------------------------------------------------------- 2000.2: git status (full-index-v3) 0.59(0.51+0.12) 2000.3: git status (full-index-v4) 0.59(0.52+0.11) 2000.4: git status (sparse-index-v3) 1.40(1.32+0.12) 2000.5: git status (sparse-index-v4) 1.41(1.36+0.08) 2000.6: git add -A (full-index-v3) 2.32(1.97+0.19) 2000.7: git add -A (full-index-v4) 2.17(1.92+0.14) 2000.8: git add -A (sparse-index-v3) 2.31(2.21+0.15) 2000.9: git add -A (sparse-index-v4) 2.30(2.20+0.13) 2000.10: git add . (full-index-v3) 2.39(2.02+0.20) 2000.11: git add . (full-index-v4) 2.20(1.94+0.16) 2000.12: git add . (sparse-index-v3) 2.36(2.27+0.12) 2000.13: git add . (sparse-index-v4) 2.33(2.21+0.16) 2000.14: git commit -a -m A (full-index-v3) 2.47(2.12+0.20) 2000.15: git commit -a -m A (full-index-v4) 2.26(2.00+0.17) 2000.16: git commit -a -m A (sparse-index-v3) 3.01(2.92+0.16) 2000.17: git commit -a -m A (sparse-index-v4) 3.01(2.94+0.15) Note that there is very little difference between the v3 and v4 index formats when the sparse-index is enabled. This is primarily due to the fact that the relative file sizes are the same, and the command time is mostly taken up by parsing tree objects to expand the sparse index into a full one. With the current file layout, the index file sizes are given by this table: | full index | sparse index | +-------------+--------------+ v3 | 108 MiB | 1.6 MiB | v4 | 80 MiB | 1.2 MiB | Future updates will improve the performance of Git commands when the index is sparse. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30t/perf: add performance test for sparse operationsDerrick Stolee1-0/+84
Create a test script that takes the default performance test (the Git codebase) and multiplies it by 256 using four layers of duplicated trees of width four. This results in nearly one million blob entries in the index. Then, we can clone this repository with sparse-checkout patterns that demonstrate four copies of the initial repository. Each clone will use a different index format or mode so peformance can be tested across the different options. Note that the initial repo is stripped of submodules before doing the copies. This preserves the expected data shape of the sparse index, because directories containing submodules are not collapsed to a sparse directory entry. Run a few Git commands on these clones, especially those that use the index (status, add, commit). Here are the results on my Linux machine: Test -------------------------------------------------------------- 2000.2: git status (full-index-v3) 0.37(0.30+0.09) 2000.3: git status (full-index-v4) 0.39(0.32+0.10) 2000.4: git add -A (full-index-v3) 1.42(1.06+0.20) 2000.5: git add -A (full-index-v4) 1.26(0.98+0.16) 2000.6: git add . (full-index-v3) 1.40(1.04+0.18) 2000.7: git add . (full-index-v4) 1.26(0.98+0.17) 2000.8: git commit -a -m A (full-index-v3) 1.42(1.11+0.16) 2000.9: git commit -a -m A (full-index-v4) 1.33(1.08+0.16) It is perhaps noteworthy that there is an improvement when using index version 4. This is because the v3 index uses 108 MiB while the v4 index uses 80 MiB. Since the repeated portions of the directories are very short (f3/f1/f2, for example) this ratio is less pronounced than in similarly-sized real repositories. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-24Merge branch 'nk/diff-index-fsmonitor'Junio C Hamano1-0/+4
"git diff-index" codepath has been taught to trust fsmonitor status to reduce number of lstat() calls. * nk/diff-index-fsmonitor: fsmonitor: add perf test for git diff HEAD fsmonitor: add assertion that fsmonitor is valid to check_removed fsmonitor: skip lstat deletion check during git diff-index
2021-03-24Merge branch 'tb/geometric-repack'Junio C Hamano1-3/+33
"git repack" so far has been only capable of repacking everything under the sun into a single pack (or split by size). A cleverer strategy to reduce the cost of repacking a repository has been introduced. * tb/geometric-repack: builtin/pack-objects.c: ignore missing links with --stdin-packs builtin/repack.c: reword comment around pack-objects flags builtin/repack.c: be more conservative with unsigned overflows builtin/repack.c: assign pack split later t7703: test --geometric repack with loose objects builtin/repack.c: do not repack single packs with --geometric builtin/repack.c: add '--geometric' option packfile: add kept-pack cache for find_kept_pack_entry() builtin/pack-objects.c: rewrite honor-pack-keep logic p5303: measure time to repack with keep p5303: add missing &&-chains builtin/pack-objects.c: add '--stdin-packs' option revision: learn '--no-kept-objects' packfile: introduce 'find_kept_pack_entry()'
2021-03-22Merge branch 'jk/perf-in-worktrees'Junio C Hamano1-9/+22
Perf test update to work better in secondary worktrees. * jk/perf-in-worktrees: t/perf: avoid copying worktree files from test repo t/perf: handle worktrees as test repos
2021-03-22pack-bitmap: avoid traversal of objects referenced by uninteresting tagPatrick Steinhardt1-0/+14
When preparing the bitmap walk, we first establish the set of of have and want objects by iterating over the set of pending objects: if an object is marked as uninteresting, it's declared as an object we already have, otherwise as an object we want. These two sets are then used to compute which transitively referenced objects we need to obtain. One special case here are tag objects: when a tag is requested, we resolve it to its first not-tag object and add both resolved objects as well as the tag itself into either the have or want set. Given that the uninteresting-property always propagates to referenced objects, it is clear that if the tag is uninteresting, so are its children and vice versa. But we fail to propagate the flag, which effectively means that referenced objects will always be interesting except for the case where they have already been marked as uninteresting explicitly. This mislabeling does not impact correctness: we now have it in our "wants" set, and given that we later do an `AND NOT` of the bitmaps of "wants" and "haves" sets it is clear that the result must be the same. But we now start to needlessly traverse the tag's referenced objects in case it is uninteresting, even though we know that each referenced object will be uninteresting anyway. In the worst case, this can lead to a complete graph walk just to establish that we do not care for any object. Fix the issue by propagating the `UNINTERESTING` flag to pointees of tag objects and add a benchmark with negative revisions to p5310. This shows some nice performance benefits, tested with linux.git: Test HEAD~ HEAD --------------------------------------------------------------------------------------------------------------- 5310.3: repack to disk 193.18(181.46+16.42) 194.61(183.41+15.83) +0.7% 5310.4: simulated clone 25.93(24.88+1.05) 25.81(24.73+1.08) -0.5% 5310.5: simulated fetch 2.64(5.30+0.69) 2.59(5.16+0.65) -1.9% 5310.6: pack to file (bitmap) 58.75(57.56+6.30) 58.29(57.61+5.73) -0.8% 5310.7: rev-list (commits) 1.45(1.18+0.26) 1.46(1.22+0.24) +0.7% 5310.8: rev-list (objects) 15.35(14.22+1.13) 15.30(14.23+1.07) -0.3% 5310.9: rev-list with tag negated via --not --all (objects) 22.49(20.93+1.56) 0.11(0.09+0.01) -99.5% 5310.10: rev-list with negative tag (objects) 0.61(0.44+0.16) 0.51(0.35+0.16) -16.4% 5310.11: rev-list count with blob:none 12.15(11.19+0.96) 12.18(11.19+0.99) +0.2% 5310.12: rev-list count with blob:limit=1k 17.77(15.71+2.06) 17.75(15.63+2.12) -0.1% 5310.13: rev-list count with tree:0 1.69(1.31+0.38) 1.68(1.28+0.39) -0.6% 5310.14: simulated partial clone 20.14(19.15+0.98) 19.98(18.93+1.05) -0.8% 5310.16: clone (partial bitmap) 12.78(13.89+1.07) 12.72(13.99+1.01) -0.5% 5310.17: pack to file (partial bitmap) 42.07(45.44+2.72) 41.44(44.66+2.80) -1.5% 5310.18: rev-list with tree filter (partial bitmap) 0.44(0.29+0.15) 0.46(0.32+0.14) +4.5% While most benchmarks are probably in the range of noise, the newly added 5310.9 and 5310.10 benchmarks consistenly perform better. Signed-off-by: Patrick Steinhardt <ps@pks.im>. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18fsmonitor: add perf test for git diff HEADNipunn Koorapati1-0/+4
Update the xargs call so that if your large repo contains symlinks, test-tool chmtime failure does not end the script. On Linux Test this tree upstream/master --------------------------------------------------------------------------------------------------------- 7519.4: status (fsmonitor=fsmonitor-watchman) 0.52(0.43+0.10) 0.53(0.49+0.05) +1.9% 7519.5: status -uno (fsmonitor=fsmonitor-watchman) 0.21(0.15+0.07) 0.22(0.13+0.09) +4.8% 7519.6: status -uall (fsmonitor=fsmonitor-watchman) 1.65(0.93+0.71) 1.69(1.03+0.65) +2.4% 7519.7: status (dirty) (fsmonitor=fsmonitor-watchman) 11.99(11.34+1.58) 11.95(11.02+1.79) -0.3% 7519.8: diff (fsmonitor=fsmonitor-watchman) 0.25(0.17+0.26) 0.25(0.18+0.26) +0.0% 7519.9: diff HEAD (fsmonitor=fsmonitor-watchman) 0.39(0.25+0.34) 0.89(0.35+0.74) +128.2% 7519.10: diff -- 0_files (fsmonitor=fsmonitor-watchman) 0.16(0.13+0.04) 0.16(0.12+0.05) +0.0% 7519.11: diff -- 10_files (fsmonitor=fsmonitor-watchman) 0.16(0.12+0.05) 0.16(0.12+0.05) +0.0% 7519.12: diff -- 100_files (fsmonitor=fsmonitor-watchman) 0.16(0.12+0.05) 0.16(0.12+0.05) +0.0% 7519.13: diff -- 1000_files (fsmonitor=fsmonitor-watchman) 0.16(0.11+0.06) 0.16(0.12+0.05) +0.0% 7519.14: diff -- 10000_files (fsmonitor=fsmonitor-watchman) 0.18(0.13+0.06) 0.17(0.10+0.08) -5.6% 7519.15: add (fsmonitor=fsmonitor-watchman) 2.25(1.53+0.68) 2.25(1.47+0.74) +0.0% 7519.18: status (fsmonitor=disabled) 0.88(0.73+1.03) 0.89(0.67+1.08) +1.1% 7519.19: status -uno (fsmonitor=disabled) 0.45(0.43+0.89) 0.45(0.34+0.98) +0.0% 7519.20: status -uall (fsmonitor=disabled) 1.88(1.16+1.58) 1.88(1.22+1.51) +0.0% 7519.21: status (dirty) (fsmonitor=disabled) 7.53(7.05+2.11) 7.53(6.98+2.04) +0.0% 7519.22: diff (fsmonitor=disabled) 0.42(0.37+0.92) 0.42(0.38+0.91) +0.0% 7519.23: diff HEAD (fsmonitor=disabled) 0.44(0.41+0.90) 0.44(0.40+0.91) +0.0% 7519.24: diff -- 0_files (fsmonitor=disabled) 0.13(0.09+0.05) 0.13(0.09+0.05) +0.0% 7519.25: diff -- 10_files (fsmonitor=disabled) 0.13(0.10+0.04) 0.13(0.10+0.04) +0.0% 7519.26: diff -- 100_files (fsmonitor=disabled) 0.13(0.09+0.05) 0.13(0.10+0.04) +0.0% 7519.27: diff -- 1000_files (fsmonitor=disabled) 0.13(0.09+0.06) 0.13(0.09+0.05) +0.0% 7519.28: diff -- 10000_files (fsmonitor=disabled) 0.14(0.11+0.05) 0.14(0.10+0.05) +0.0% 7519.29: add (fsmonitor=disabled) 2.43(1.61+1.64) 2.43(1.69+1.57) +0.0% On linux (2.29.2 vs w/ this patch): nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff 2>&1 | grep lstat 0.04 0.000063 3 20 6 lstat nipunn@nipunn-dbx:~/src/server3$ strace -f -c git diff HEAD 2>&1 | grep lstat 94.98 5.242262 10 523783 13 lstat nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff 2>&1 | grep lstat 0.38 0.000032 5 7 3 lstat nipunn@nipunn-dbx:~/src/server3$ strace -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep lstat 99.44 0.741892 9 81634 10 lstat On mac (2.29.2 vs w/ this patch): nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff 2>&1 | grep "^lstat64 " lstat64 8 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c git diff HEAD 2>&1 | grep "^lstat64 " lstat64 120242 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff 2>&1 | grep "^lstat64 " lstat64 4 nipunn-mbp:server nipunn$ sudo dtruss -L -f -c ../git/bin-wrappers/git diff HEAD 2>&1 | grep "^lstat64 " lstat64 4497 There are still a bunch of lstats - on directories, but not every file. Progress! Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-01Merge branch 'jh/fsmonitor-prework'Junio C Hamano3-12/+64
Preliminary changes to fsmonitor integration. * jh/fsmonitor-prework: fsmonitor: refactor initialization of fsmonitor_last_update token fsmonitor: allow all entries for a folder to be invalidated fsmonitor: log FSMN token when reading and writing the index fsmonitor: log invocation of FSMonitor hook to trace2 read-cache: log the number of scanned files to trace2 read-cache: log the number of lstat calls to trace2 preload-index: log the number of lstat calls to trace2 p7519: add trace logging during perf test p7519: move watchman cleanup earlier in the test p7519: fix watchman watch-list test on Windows p7519: do not rely on "xargs -d" in test
2021-02-26t/perf: avoid copying worktree files from test repoJeff King1-1/+1
When running the perf suite, we copy files from an existing $GIT_DIR to a scratch repository to give us a realistic setup on which to operate. Since the perf scripts themselves may modify the scratch repository, we want to make sure we've scrubbed any references back to the original. One existing example is that we avoid copying the file "commondir" at the top-level of the repository. In a worktree git-dir (e.g., .git/worktrees/foo), that file contains the path to the parent repository; copying it could mean ref updates in the scratch repository affect the original. But there are other files we should cover, too: - "gitdir" in a worktree git-dir contains the path to the actual .git file in the working tree. We _shouldn't_ end up looking at it at all, since the lack of a "commondir" file means Git won't consider this to be a worktree git-dir. But it's best to err on the safe side. - in a parent repository that contains worktrees, the "$GIT_DIR/worktrees" directory will contain the git dirs for the individual worktrees. Which will themselves contain commondir and gitdir files that may reference the original repository. We should likewise remove them. Note that this does mean that the perf suite's scratch repositories will never have any worktrees. That's OK; we don't have any perf tests that are influenced by their presence. If we add any, they'd probably want to create the worktrees themselves anyway. This patch adds both paths to the set of omissions in test_perf_copy_repo_contents(). Note that we won't get confused here by matching arbitrary names like refs/heads/commondir. This list is always matching top-level entries in $GIT_DIR (we rely on "cp -R" to do the actual recursion). Suggested-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-26t/perf: handle worktrees as test reposJeff King1-9/+22
The perf suite gets confused when test_perf_default_repo is pointed at a worktree (which includes when it is run from within a worktree at all, since the default is to use the current repository). Here's an example: $ git worktree add ~/foo Preparing worktree (new branch 'foo') HEAD is now at 328c109303 The eighth batch $ cd ~/foo $ make [...build output...] $ cd t/perf $ ./p0000-perf-lib-sanity.sh -v -i [...] perf 1 - test_perf_default_repo works: running: foo=$(git rev-parse HEAD) && test_export foo fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree. Use '--' to separate paths from revisions, like this: 'git <command> [<revision>...] -- [<file>...]' The problem is that we didn't copy all of the necessary files from the source repository (in this case we got HEAD, but we have no refs!). We discover the git-dir with "rev-parse --git-dir", but this points to the worktree's partial repository in .../.git/worktrees/foo. That partial repository has a "commondir" file which points to the main repository, where the actual refs are stored, but we don't copy it. This is the correct thing to do, though! If we did copy it, then our scratch test repo would be pointing back to the original main repo, and any ref updates we made in the tests would impact that original repo. Instead, we need to either: 1. Make a scratch copy of the original main repo (in addition to the worktree repo), and point the scratch worktree repo's commondir at it. This preserves the original relationship, but it's doubtful any script really cares (if they are testing worktree performance, they'd probably make their own worktrees). And it's trickier to get right. 2. Collapse the main and worktree repos into a single scratch repo. This can be done by copying everything from both, preferring any files from the worktree repo. This patch does the second one. With this applied, the example above results in p0000 running successfully. Reported-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22p5303: measure time to repack with keepJeff King1-2/+32
Add two new tests to measure repack performance. Both tests split the repository into synthetic "pushes", and then leave the remaining objects in a big base pack. The first new test marks an empty pack as "kept" and then passes --honor-pack-keep to avoid including objects in it. That doesn't change the resulting pack, but it does let us compare to the normal repack case to see how much overhead we add to check whether objects are kept or not. The other test is of --stdin-packs, which gives us a sense of how that number scales based on the number of packs we provide as input. In each of those tests, the empty pack isn't considered, but the residual pack (objects that were left over and not included in one of the synthetic push packs) is marked as kept. (Note that in the single-pack case of the --stdin-packs test, there is nothing do since there are no non-excluded packs). Here are some timings on a recent clone of the kernel: 5303.5: repack (1) 57.26(54.59+10.84) 5303.6: repack with kept (1) 57.33(54.80+10.51) in the 50-pack case, things start to slow down: 5303.11: repack (50) 71.54(88.57+4.84) 5303.12: repack with kept (50) 85.12(102.05+4.94) and by the time we hit 1,000 packs, things are substantially worse, even though the resulting pack produced is the same: 5303.17: repack (1000) 216.87(490.79+14.57) 5303.18: repack with kept (1000) 665.63(938.87+15.76) That's because the code paths around handling .keep files are known to scale badly; they look in every single pack file to find each object. Our solution to that was to notice that most repos don't have keep files, and to make that case a fast path. But as soon as you add a single .keep, that part of pack-objects slows down again (even if we have fewer objects total to look at). Likewise, the scaling is pretty extreme on --stdin-packs (but each subsequent test is also being asked to do more work): 5303.7: repack with --stdin-packs (1) 0.01(0.01+0.00) 5303.13: repack with --stdin-packs (50) 3.53(12.07+0.24) 5303.19: repack with --stdin-packs (1000) 195.83(371.82+8.10) Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22p5303: add missing &&-chainsJeff King1-2/+2
These are in a helper function, so the usual chain-lint doesn't notice them. This function is still not perfect, as it has some git invocations on the left-hand-side of the pipe, but it's primary purpose is timing, not finding bugs or correctness issues. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16p7519: add trace logging during perf testJeff Hostetler3-2/+35
Add optional trace logging to allow us to better compare performance of various fsmonitor providers and compare results with non-fsmonitor runs. Currently, this includes Trace2 logging, but may be extended to include other trace targets, such as GIT_TRACE_FSMONITOR if desired. Using this logging helped me explain an odd behavior on MacOS where the kernel was dropping events and causing the hook to Watchman to timeout. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16p7519: move watchman cleanup earlier in the testJeff Hostetler1-8/+17
Shutdown Watchman after the Watchman-based tests and before the block of "no fsmonitor" tests. This helps ensure that Watchman cannot affect the test results for the other. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16p7519: fix watchman watch-list test on WindowsJeff Hostetler1-1/+1
Only use the final portion of the test trash directory file name when verifying that Watchman was started. On Windows and under the SDK, $GIT_WORKTREE is a cygwin-style path with forward slashes and a "/c/" drive name. However `watchman watch-list` reports a proper Windows-style pathname with drive letters and backslashes. This causes the grep to fail. Since we don't really care about the full pathname (and we really don't want to bother with normalizaing them), just see if the test-name portion of the path is found. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16p7519: do not rely on "xargs -d" in testJeff Hostetler1-1/+11
Convert the test to use a more portable method to update the mtime on a large number of files under version control. The Mac version of xargs does not support the "-d" option. Likewise, the "-0" and "--null" options are not portable. Furthermore, use `test-tool chmtime` rather than `touch` to update the mtime to ensure that it is actually updated (especially on file systems with only whole second resolution). Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-10Merge branch 'jk/pretty-lazy-load-commit'Junio C Hamano1-1/+1
Some pretty-format specifiers do not need the data in commit object (e.g. "%H"), but we were over-eager to load and parse it, which has been made even lazier. * jk/pretty-lazy-load-commit: pretty: lazy-load commit data when expanding user-format
2021-02-08Merge branch 'jk/p5303-sed-portability-fix' into maintJunio C Hamano1-4/+8
A perf script was made more portable. * jk/p5303-sed-portability-fix: p5303: avoid sed GNU-ism
2021-02-05Merge branch 'jk/p5303-sed-portability-fix'Junio C Hamano1-4/+8
A perf script was made more portable. * jk/p5303-sed-portability-fix: p5303: avoid sed GNU-ism
2021-02-05Merge branch 'nk/perf-fsmonitor-cleanup' into maintJunio C Hamano1-1/+6
Test fix. * nk/perf-fsmonitor-cleanup: p7519: allow running without watchman prereq
2021-01-29p5303: avoid sed GNU-ismJeff King1-4/+8
Using "1~5" isn't portable. Nobody seems to have noticed, since perhaps people don't tend to run the perf suite on more exotic platforms. Still, it's better to set a good example. We can use: perl -ne 'print if $. % 5 == 1' instead. But we can further observe that perl does a good job of the other parts of this pipeline, and fold the whole thing together. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-28pretty: lazy-load commit data when expanding user-formatJeff King1-1/+1
When we expand a user-format, we try to avoid work that isn't necessary for the output. For instance, we don't bother parsing the commit header until we know we need the author, subject, etc. But we do always load the commit object's contents from disk, even if the format doesn't require it (e.g., just "%H"). Traditionally this didn't matter much, because we'd have loaded it as part of the traversal anyway, and we'd typically have those bytes attached to the commit struct (or these days, cached in a commit-slab). But when we have a commit-graph, we might easily get to the point of pretty-printing a commit without ever having looked at the actual object contents. We should push off that load (and reencoding) until we're certain that it's needed. I think the results of p4205 show the advantage pretty clearly (we serve parent and tree oids out of the commit struct itself, so they benefit as well): # using git.git as the test repo Test HEAD^ HEAD ---------------------------------------------------------------------- 4205.1: log with %H 0.40(0.39+0.01) 0.03(0.02+0.01) -92.5% 4205.2: log with %h 0.45(0.44+0.01) 0.09(0.09+0.00) -80.0% 4205.3: log with %T 0.40(0.39+0.00) 0.04(0.04+0.00) -90.0% 4205.4: log with %t 0.46(0.46+0.00) 0.09(0.08+0.01) -80.4% 4205.5: log with %P 0.39(0.39+0.00) 0.03(0.03+0.00) -92.3% 4205.6: log with %p 0.46(0.46+0.00) 0.10(0.09+0.00) -78.3% 4205.7: log with %h-%h-%h 0.52(0.51+0.01) 0.15(0.14+0.00) -71.2% 4205.8: log with %an-%ae-%s 0.42(0.41+0.00) 0.42(0.41+0.01) +0.0% # using linux.git as the test repo Test HEAD^ HEAD ---------------------------------------------------------------------- 4205.1: log with %H 7.12(6.97+0.14) 0.76(0.65+0.11) -89.3% 4205.2: log with %h 7.35(7.19+0.16) 1.30(1.19+0.11) -82.3% 4205.3: log with %T 7.58(7.42+0.15) 1.02(0.94+0.08) -86.5% 4205.4: log with %t 8.05(7.89+0.15) 1.55(1.41+0.13) -80.7% 4205.5: log with %P 7.12(7.01+0.10) 0.76(0.69+0.07) -89.3% 4205.6: log with %p 7.38(7.27+0.10) 1.32(1.20+0.12) -82.1% 4205.7: log with %h-%h-%h 7.81(7.67+0.13) 1.79(1.67+0.12) -77.1% 4205.8: log with %an-%ae-%s 7.90(7.74+0.15) 7.81(7.66+0.15) -1.1% I added the final test to show where we don't improve (the 1% there is just lucky noise), but also as a regression test to make sure we're not doing anything stupid like loading the commit multiple times when there are several placeholders that need it. Reported-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-15Merge branch 'nk/perf-fsmonitor-cleanup'Junio C Hamano1-1/+6
Test fix. * nk/perf-fsmonitor-cleanup: p7519: allow running without watchman prereq
2021-01-06Merge branch 'es/perf-export-fix'Junio C Hamano1-4/+1
Tweak unneeded recursion from a test framework helper function. * es/perf-export-fix: t/perf: avoid unnecessary test_export() recursion
2021-01-06p7519: allow running without watchman prereqTaylor Blau1-1/+6
p7519 measures the performance of the fsmonitor code. To do this, it uses the installed copy of Watchman. If Watchman isn't installed, a noop integration script is installed in its place. When in the latter mode, it is expected that the script should not write a "last update token": in fact, it doesn't write anything at all since the script is blank. Commit 33226af42b (t/perf/fsmonitor: improve error message if typoing hook name, 2020-10-26) made sure that running 'git update-index --fsmonitor' did not write anything to stderr, but this is not the case when using the empty Watchman script, since Git will complain that: $ which watchman watchman not found $ cat .git/hooks/fsmonitor-empty $ git -c core.fsmonitor=.git/hooks/fsmonitor-empty update-index --fsmonitor warning: Empty last update token. Prior to 33226af42b, the output wasn't checked at all, which allowed this noop mode to work. But, 33226af42b breaks p7519 when running it without a 'watchman(1)' on your system. Handle this by only checking that the stderr is empty only when running with a real watchman executable. Otherwise, assert that the error message is the expected one when running in the noop mode. Signed-off-by: Taylor Blau <me@ttaylorr.com> Acked-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-22t/perf: avoid unnecessary test_export() recursionEric Sunshine1-4/+1
test_export() has been self-recursive since its inception even though a simple for-loop would have served just as well to append its arguments to the `test_export_` variable separated by the pipe character "|". Recently `test_export_` was changed instead to a space-separated list of tokens to be exported, an operation which can be accomplished via a single simple assignment, with no need for looping or recursion. Therefore, simplify the implementation. While at it, take advantage of the fact that variable names to be exported are shell identifiers, thus won't be composed of special characters or whitespace, thus simple a `$*` can be used rather than magical `"$@"`. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-18Merge branch 'es/perf-export-fix'Junio C Hamano1-2/+7
Dev-support fix for BSD. * es/perf-export-fix: t/perf: fix test_export() failure with BSD `sed`
2020-12-16t/perf: fix test_export() failure with BSD `sed`Eric Sunshine1-2/+7
test_perf() runs each test in its own subshell which makes it difficult to persist variables between tests. test_export() addresses this shortcoming by grabbing the values of specified variables after a test runs but before the subshell exits, and writes those values to a file which is loaded into the environment of subsequent tests. To grab the values to be persisted, test_export() pipes the output of the shell's builtin `set` command through `sed` which plucks them out using a regular expression along the lines of `s/^(var1|var2)/.../p`. Unfortunately, though, this use of alternation is not portable. For instance, BSD-lineage `sed` (including macOS `sed`) does not support it in the default "basic regular expression" mode (BRE). It may be possible to enable "extended regular expression" mode (ERE) in some cases with `sed -E`, however, `-E` is neither portable nor part of POSIX. Fortunately, alternation is unnecessary in this case and can easily be avoided, so replace it with a series of simple expressions such as `s/^var1/.../p;s/^var2/.../p`. While at it, tighten the expressions so they match the variable names exactly rather than matching prefixes (i.e. use `s/^var1=/.../p`). If the requirements of test_export() become more complex in the future, then an alternative would be to replace `sed` with `perl` which supports alternation on all platforms, however, the simple elimination of alternation via multiple `sed` expressions suffices for the present. Reported-by: Sangeeta <sangunb09@gmail.com> Diagnosed-by: Philippe Blain <levraiphilippeblain@gmail.com> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-08Merge branch 'nk/perf-fsmonitor-cleanup'Junio C Hamano1-2/+1
Test clean-up. * nk/perf-fsmonitor-cleanup: perf/fsmonitor: use test_must_be_empty helper
2020-12-08Merge branch 'ps/update-ref-multi-transaction'Junio C Hamano1-13/+7
"git update-ref --stdin" learns to take multiple transactions in a single session. * ps/update-ref-multi-transaction: update-ref: disallow "start" for ongoing transactions p1400: use `git-update-ref --stdin` to test multiple transactions update-ref: allow creation of multiple transactions t1400: avoid touching refs on filesystem
2020-11-30perf/fsmonitor: use test_must_be_empty helperNipunn Koorapati1-2/+1
Simplify test and make error messages more clear here. Per feedback from Junio in 33226af42b (t/perf/fsmonitor: improve error message if typoing hook name, 2020-10-26) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16p1400: use `git-update-ref --stdin` to test multiple transactionsPatrick Steinhardt1-13/+7
In commit 0a0fbbe3ff (refs: remove lookup cache for reference-transaction hook, 2020-08-25), a new benchmark was added to p1400 which has the intention to exercise creation of multiple transactions in a single process. As git-update-ref wasn't yet able to create multiple transactions with a single run we instead used git-push. As its non-atomic version creates a transaction per reference update, this was the best approximation we could make at that point in time. Now that `git-update-ref --stdin` supports creation of multiple transactions, let's convert the benchmark to use that instead. It has less overhead and it's also a lot clearer what the actual intention is. Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: add benchmark for dirty statusNipunn Koorapati1-0/+5
This benchmark covers the git status time for a heavily dirty directory - benchmarking fsmonitor's refresh When running to compare our perl vs rs-git-fsmonitor - we see that the perl script incurs significant overhead - further motivation to provide a faster implementation within git. 7519.7: status (dirty) (fsmonitor=query-watchman) 10.05(7.78+1.56) 7519.20: status (dirty) (fsmonitor=rs-git-fsmonitor) 6.72(4.37+1.64) 7519.33: status (dirty) (fsmonitor=disabled) 5.62(4.24+2.03) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: perf comparison of multiple fsmonitor integrationsNipunn Koorapati1-8/+14
Allows for simple perf comparison of different integrations. I ran it to compare our perl script w/ rs-git-fsmonitor and found 20-30ms of overhead on every command. Output looks like this (extra newlines added for readability) Test this tree --------------------------------------------------------------------------- 7519.4: status (fsmonitor=query-watchman) 0.42(0.37+0.05) 7519.5: status -uno (fsmonitor=query-watchman) 0.19(0.12+0.07) 7519.6: status -uall (fsmonitor=query-watchman) 1.36(0.73+0.62) 7519.7: diff (fsmonitor=query-watchman) 0.14(0.09+0.05) 7519.8: diff -- 0_files (fsmonitor=query-watchman) 0.14(0.11+0.03) 7519.9: diff -- 10_files (fsmonitor=query-watchman) 0.14(0.10+0.04) 7519.10: diff -- 100_files (fsmonitor=query-watchman) 0.14(0.09+0.05) 7519.11: diff -- 1000_files (fsmonitor=query-watchman) 0.14(0.08+0.06) 7519.12: diff -- 10000_files (fsmonitor=query-watchman) 0.14(0.09+0.05) 7519.13: add (fsmonitor=query-watchman) 2.04(1.32+0.66) 7519.16: status (fsmonitor=rs-git-fsmonitor) 0.39(0.32+0.08) 7519.17: status -uno (fsmonitor=rs-git-fsmonitor) 0.17(0.11+0.06) 7519.18: status -uall (fsmonitor=rs-git-fsmonitor) 1.33(0.71+0.61) 7519.19: diff (fsmonitor=rs-git-fsmonitor) 0.11(0.07+0.04) 7519.20: diff -- 0_files (fsmonitor=rs-git-fsmonitor) 0.11(0.09+0.03) 7519.21: diff -- 10_files (fsmonitor=rs-git-fsmonitor) 0.11(0.09+0.03) 7519.22: diff -- 100_files (fsmonitor=rs-git-fsmonitor) 0.11(0.07+0.04) 7519.23: diff -- 1000_files (fsmonitor=rs-git-fsmonitor) 0.11(0.06+0.06) 7519.24: diff -- 10000_files (fsmonitor=rs-git-fsmonitor) 0.11(0.06+0.06) 7519.25: add (fsmonitor=rs-git-fsmonitor) 2.03(1.28+0.69) 7519.28: status (fsmonitor=disabled) 0.77(0.59+0.99) 7519.29: status -uno (fsmonitor=disabled) 0.42(0.33+0.85) 7519.30: status -uall (fsmonitor=disabled) 1.59(1.02+1.34) 7519.31: diff (fsmonitor=disabled) 0.35(0.30+0.81) 7519.32: diff -- 0_files (fsmonitor=disabled) 0.11(0.08+0.04) 7519.33: diff -- 10_files (fsmonitor=disabled) 0.11(0.07+0.04) 7519.34: diff -- 100_files (fsmonitor=disabled) 0.11(0.08+0.03) 7519.35: diff -- 1000_files (fsmonitor=disabled) 0.11(0.10+0.02) 7519.36: diff -- 10000_files (fsmonitor=disabled) 0.12(0.07+0.06) 7519.37: add (fsmonitor=disabled) 2.24(1.48+1.44) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: initialize test with git resetNipunn Koorapati1-2/+6
Previously, the git add of the previous suiterun would pollute the numbers in the second run Before: Test this tree ----------------------------------------------------------------------------- 7519.4: status (fsmonitor=fsmonitor-watchman) 0.40(0.36+0.04) 7519.5: status -uno (fsmonitor=fsmonitor-watchman) 0.19(0.12+0.07) 7519.6: status -uall (fsmonitor=fsmonitor-watchman) 1.36(0.74+0.61) 7519.7: diff (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.04) 7519.8: diff -- 0_files (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.04) 7519.9: diff -- 10_files (fsmonitor=fsmonitor-watchman) 0.14(0.09+0.05) 7519.10: diff -- 100_files (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.04) 7519.11: diff -- 1000_files (fsmonitor=fsmonitor-watchman) 0.14(0.08+0.06) 7519.12: diff -- 10000_files (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.04) 7519.13: add (fsmonitor=fsmonitor-watchman) 2.03(1.28+0.69) 7519.16: status (fsmonitor=disabled) 0.64(0.49+0.90) 7519.17: status -uno (fsmonitor=disabled) 1.15(0.92+1.00) 7519.18: status -uall (fsmonitor=disabled) 2.32(1.46+1.55) 7519.19: diff (fsmonitor=disabled) 1.44(1.12+1.76) 7519.20: diff -- 0_files (fsmonitor=disabled) 0.11(0.07+0.05) 7519.21: diff -- 10_files (fsmonitor=disabled) 0.11(0.06+0.05) 7519.22: diff -- 100_files (fsmonitor=disabled) 0.11(0.08+0.03) 7519.23: diff -- 1000_files (fsmonitor=disabled) 0.11(0.08+0.04) 7519.24: diff -- 10000_files (fsmonitor=disabled) 0.12(0.06+0.07) 7519.25: add (fsmonitor=disabled) 2.25(1.47+1.47) After: Test this tree ----------------------------------------------------------------------------- 7519.4: status (fsmonitor=fsmonitor-watchman) 0.41(0.33+0.09) 7519.5: status -uno (fsmonitor=fsmonitor-watchman) 0.20(0.14+0.07) 7519.6: status -uall (fsmonitor=fsmonitor-watchman) 1.37(0.78+0.58) 7519.7: diff (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.04) 7519.8: diff -- 0_files (fsmonitor=fsmonitor-watchman) 0.14(0.08+0.06) 7519.9: diff -- 10_files (fsmonitor=fsmonitor-watchman) 0.14(0.09+0.05) 7519.10: diff -- 100_files (fsmonitor=fsmonitor-watchman) 0.14(0.10+0.05) 7519.11: diff -- 1000_files (fsmonitor=fsmonitor-watchman) 0.14(0.11+0.04) 7519.12: diff -- 10000_files (fsmonitor=fsmonitor-watchman) 0.14(0.09+0.05) 7519.13: add (fsmonitor=fsmonitor-watchman) 2.04(1.27+0.71) 7519.16: status (fsmonitor=disabled) 0.78(0.59+0.99) 7519.17: status -uno (fsmonitor=disabled) 0.43(0.32+0.88) 7519.18: status -uall (fsmonitor=disabled) 1.58(0.96+1.38) 7519.19: diff (fsmonitor=disabled) 0.36(0.31+0.79) 7519.20: diff -- 0_files (fsmonitor=disabled) 0.11(0.08+0.03) 7519.21: diff -- 10_files (fsmonitor=disabled) 0.11(0.07+0.04) 7519.22: diff -- 100_files (fsmonitor=disabled) 0.11(0.08+0.04) 7519.23: diff -- 1000_files (fsmonitor=disabled) 0.11(0.07+0.05) 7519.24: diff -- 10000_files (fsmonitor=disabled) 0.12(0.08+0.05) 7519.25: add (fsmonitor=disabled) 2.25(1.48+1.47) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: factor setup for fsmonitor into functionNipunn Koorapati1-2/+6
This prepares for it being called multiple times when testing different hooks Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: silence initial git commitNipunn Koorapati1-1/+1
It is extremely verbose, printing >10K non-useful lines Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: shorten DESC to basenameNipunn Koorapati1-1/+5
The full name is lengthy and makes it hard to read Before: 7519.3: status (fsmonitor=/home/nipunn/src/server/.git/hooks/rs-git-fsmonitor) 0.02(0.01+0.00) After 7519.3: status (fsmonitor=rs-git-fsmonitor) 0.03(0.02+0.00) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: factor description out for readabilityNipunn Koorapati1-10/+12
There was much duplication here. Prepares for making changes to the description. Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: improve error message if typoing hook nameNipunn Koorapati1-1/+3
Previously - it would silently run the perf suite w/o using fsmonitor - fsmonitor errors are not hard failures. Now it errors loudly. GIT_PERF_7519_FSMONITOR="$HOME/rs-git-fsmonitorr" ./p7519-fsmonitor.sh -i -v fatal: cannot run /home/nipunn/rs-git-fsmonitorr: No such file or directory not ok 2 - setup for fsmonitor Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: move watchman setup to one-time-repo-setupNipunn Koorapati1-7/+9
It is only required to be set up once. This prepares for testing multiple hooks in one invocation. Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26t/perf/fsmonitor: separate one time repo initializationNipunn Koorapati1-8/+11
In preparation for testing multiple fsmonitor hooks Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20p7519-fsmonitor: add a git add benchmarkNipunn Koorapati1-0/+4
Test v2.29.0-rc1 this tree ----------------------------------------------------------------------------------------------------------------- 7519.2: status (fsmonitor=.git/hooks/fsmonitor-watchman) 1.48(0.79+0.67) 1.48(0.79+0.67) +0.0% 7519.3: status -uno (fsmonitor=.git/hooks/fsmonitor-watchman) 0.16(0.11+0.05) 0.17(0.13+0.04) +6.3% 7519.4: status -uall (fsmonitor=.git/hooks/fsmonitor-watchman) 1.36(0.77+0.58) 1.37(0.72+0.63) +0.7% 7519.5: diff (fsmonitor=.git/hooks/fsmonitor-watchman) 0.84(0.21+0.63) 0.14(0.11+0.03) -83.3% 7519.6: diff -- 0_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.07+0.05) 0.13(0.09+0.04) +8.3% 7519.7: diff -- 10_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.09+0.04) 0.13(0.07+0.06) +8.3% 7519.8: diff -- 100_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.08+0.05) 0.12(0.08+0.05) +0.0% 7519.9: diff -- 1000_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.08+0.05) 0.13(0.09+0.04) +8.3% 7519.10: diff -- 10000_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.14(0.08+0.06) 0.13(0.07+0.06) -7.1% 7519.11: add (fsmonitor=.git/hooks/fsmonitor-watchman) 2.75(1.41+1.27) 2.03(1.26+0.70) -26.2% 7519.13: status (fsmonitor=) 1.38(1.03+1.04) 1.37(1.04+1.04) -0.7% 7519.14: status -uno (fsmonitor=) 1.11(0.83+0.98) 1.10(0.89+0.90) -0.9% 7519.15: status -uall (fsmonitor=) 2.30(1.57+1.42) 2.31(1.49+1.50) +0.4% 7519.16: diff (fsmonitor=) 1.43(1.13+1.76) 1.46(1.19+1.72) +2.1% 7519.17: diff -- 0_files (fsmonitor=) 0.10(0.08+0.04) 0.11(0.08+0.04) +10.0% 7519.18: diff -- 10_files (fsmonitor=) 0.10(0.07+0.05) 0.11(0.08+0.04) +10.0% 7519.19: diff -- 100_files (fsmonitor=) 0.10(0.07+0.04) 0.11(0.07+0.05) +10.0% 7519.20: diff -- 1000_files (fsmonitor=) 0.10(0.08+0.03) 0.11(0.08+0.04) +10.0% 7519.21: diff -- 10000_files (fsmonitor=) 0.11(0.08+0.05) 0.12(0.07+0.06) +9.1% 7519.22: add (fsmonitor=) 2.26(1.46+1.49) 2.27(1.42+1.55) +0.4% Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20p7519-fsmonitor: refactor to avoid code duplicationNipunn Koorapati1-99/+37
Much of the benchmark code is redundant. This is easier to understand and edit. Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20perf lint: add make test-lint to perf testsNipunn Koorapati2-4/+7
Perf tests have not been linted for some time. They've grown some seq instead of test_seq. This runs the existing lints on the perf tests as well. Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20t/perf: add fsmonitor perf test for git diffNipunn Koorapati1-0/+71
Results for the git-diff fsmonitor optimization in patch in the parent-rev (using a 400k file repo to test) As you can see here - git diff with fsmonitor running is significantly better with this patch series (80% faster on my workload)! GIT_PERF_LARGE_REPO=~/src/server ./run v2.29.0-rc1 . -- p7519-fsmonitor.sh Test v2.29.0-rc1 this tree ----------------------------------------------------------------------------------------------------------------- 7519.2: status (fsmonitor=.git/hooks/fsmonitor-watchman) 1.46(0.82+0.64) 1.47(0.83+0.62) +0.7% 7519.3: status -uno (fsmonitor=.git/hooks/fsmonitor-watchman) 0.16(0.12+0.04) 0.17(0.12+0.05) +6.3% 7519.4: status -uall (fsmonitor=.git/hooks/fsmonitor-watchman) 1.36(0.73+0.62) 1.37(0.76+0.60) +0.7% 7519.5: diff (fsmonitor=.git/hooks/fsmonitor-watchman) 0.85(0.22+0.63) 0.14(0.10+0.05) -83.5% 7519.6: diff -- 0_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.08+0.05) 0.13(0.11+0.02) +8.3% 7519.7: diff -- 10_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.08+0.04) 0.13(0.09+0.04) +8.3% 7519.8: diff -- 100_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.07+0.05) 0.13(0.07+0.06) +8.3% 7519.9: diff -- 1000_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.12(0.09+0.04) 0.13(0.08+0.05) +8.3% 7519.10: diff -- 10000_files (fsmonitor=.git/hooks/fsmonitor-watchman) 0.14(0.09+0.05) 0.13(0.10+0.03) -7.1% 7519.12: status (fsmonitor=) 1.67(0.93+1.49) 1.67(0.99+1.42) +0.0% 7519.13: status -uno (fsmonitor=) 0.37(0.30+0.82) 0.37(0.33+0.79) +0.0% 7519.14: status -uall (fsmonitor=) 1.58(0.97+1.35) 1.57(0.86+1.45) -0.6% 7519.15: diff (fsmonitor=) 0.34(0.28+0.83) 0.34(0.27+0.83) +0.0% 7519.16: diff -- 0_files (fsmonitor=) 0.09(0.06+0.04) 0.09(0.08+0.02) +0.0% 7519.17: diff -- 10_files (fsmonitor=) 0.09(0.07+0.03) 0.09(0.06+0.05) +0.0% 7519.18: diff -- 100_files (fsmonitor=) 0.09(0.06+0.04) 0.09(0.06+0.04) +0.0% 7519.19: diff -- 1000_files (fsmonitor=) 0.09(0.06+0.04) 0.09(0.05+0.05) +0.0% 7519.20: diff -- 10000_files (fsmonitor=) 0.10(0.08+0.04) 0.10(0.06+0.05) +0.0% I also added a benchmark for a tiny git diff workload w/ a pathspec. I see an approximately .02 second overhead added w/ and w/o fsmonitor From looking at these results, I suspected that refresh_fsmonitor is already happening during git diff - independent of this patch series' optimization. Confirmed that suspicion by breaking on refresh_fsmonitor. (gdb) bt [simplified] 0 refresh_fsmonitor at fsmonitor.c:176 1 ie_match_stat at read-cache.c:375 2 match_stat_with_submodule at diff-lib.c:237 4 builtin_diff_files at builtin/diff.c:260 5 cmd_diff at builtin/diff.c:541 6 run_builtin at git.c:450 7 handle_builtin at git.c:700 8 run_argv at git.c:767 9 cmd_main at git.c:898 10 main at common-main.c:52 Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20t/perf/p7519-fsmonitor.sh: warm cache on first git statusNipunn Koorapati1-1/+2
The first git status would be inflated due to warming of filesystem cache. This makes the results comparable. Before Test this tree -------------------------------------------------------------------------------- 7519.2: status (fsmonitor=.git/hooks/fsmonitor-watchman) 2.52(1.59+1.56) 7519.3: status -uno (fsmonitor=.git/hooks/fsmonitor-watchman) 0.18(0.12+0.06) 7519.4: status -uall (fsmonitor=.git/hooks/fsmonitor-watchman) 1.36(0.73+0.62) 7519.7: status (fsmonitor=) 0.69(0.52+0.90) 7519.8: status -uno (fsmonitor=) 0.37(0.28+0.81) 7519.9: status -uall (fsmonitor=) 1.53(0.93+1.32) After Test this tree -------------------------------------------------------------------------------- 7519.2: status (fsmonitor=.git/hooks/fsmonitor-watchman) 0.39(0.33+0.06) 7519.3: status -uno (fsmonitor=.git/hooks/fsmonitor-watchman) 0.17(0.13+0.05) 7519.4: status -uall (fsmonitor=.git/hooks/fsmonitor-watchman) 1.34(0.77+0.56) 7519.7: status (fsmonitor=) 0.70(0.53+0.90) 7519.8: status -uno (fsmonitor=) 0.37(0.32+0.78) 7519.9: status -uall (fsmonitor=) 1.55(1.01+1.25) Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-20t/perf/README: elaborate on output formatNipunn Koorapati1-0/+2
Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-22Merge branch 'jk/dont-count-existing-objects-twice'Junio C Hamano1-0/+4
There is a logic to estimate how many objects are in the repository, which is mean to run once per process invocation, but it ran every time the estimated value was requested. * jk/dont-count-existing-objects-twice: packfile: actually set approximate_object_count_valid
2020-09-17packfile: actually set approximate_object_count_validJeff King1-0/+4
The approximate_object_count() function tries to compute the count only once per process. But ever since it was introduced in 8e3f52d778 (find_unique_abbrev: move logic out of get_short_sha1(), 2016-10-03), we failed to actually set the "valid" flag, meaning we'd compute it fresh on every call. This turns out not to be _too_ bad, because we're only iterating through the packed_git list, and not making any system calls. But since it may get called for every abbreviated hash we output, even this can add up if you have many packs. Here are before-and-after timings for a new perf test which just asks rev-list to abbreviate each commit hash (the test repo is linux.git, with commit-graphs): Test origin HEAD ---------------------------------------------------------------------------- 5303.3: rev-list (1) 28.91(28.46+0.44) 29.03(28.65+0.38) +0.4% 5303.4: abbrev-commit (1) 1.18(1.06+0.11) 1.17(1.02+0.14) -0.8% 5303.7: rev-list (50) 28.95(28.56+0.38) 29.50(29.17+0.32) +1.9% 5303.8: abbrev-commit (50) 3.67(3.56+0.10) 3.57(3.42+0.15) -2.7% 5303.11: rev-list (1000) 30.34(29.89+0.43) 30.82(30.35+0.46) +1.6% 5303.12: abbrev-commit (1000) 86.82(86.52+0.29) 77.82(77.59+0.22) -10.4% 5303.15: load 10,000 packs 0.08(0.02+0.05) 0.08(0.02+0.06) +0.0% It doesn't help at all when we have 1 pack (5303.4), but we get a 10% speedup when there are 1000 packs (5303.12). That's a modest speedup for a case that's already slow and we'd hope to avoid in general (note how slow it is even after, because we have to look in each of those packs for abbreviations). But it's a one-line change that clearly matches the original intent, so it seems worth doing. The included perf test may also be useful for keeping an eye on any regressions in the overall abbreviation code. Reported-by: Rasmus Villemoes <rv@rasmusvillemoes.dk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31Merge branch 'ps/ref-transaction-hook'Junio C Hamano1-3/+10
Code simplification by removing ineffective optimization. * ps/ref-transaction-hook: refs: remove lookup cache for reference-transaction hook
2020-08-25refs: remove lookup cache for reference-transaction hookPatrick Steinhardt1-3/+10
When adding the reference-transaction hook, there were concerns about the performance impact it may have on setups which do not make use of the new hook at all. After all, it gets executed every time a reftx is prepared, committed or aborted, which linearly scales with the number of reference-transactions created per session. And as there are code paths like `git push` which create a new transaction for each reference to be updated, this may translate to calling `find_hook()` quite a lot. To address this concern, a cache was added with the intention to not repeatedly do negative hook lookups. Turns out this cache caused a regression, which was fixed via e5256c82e5 (refs: fix interleaving hook calls with reference-transaction hook, 2020-08-07). In the process of discussing the fix, we realized that the cache doesn't really help even in the negative-lookup case. While performance tests added to benchmark this did show a slight improvement in the 1% range, this really doesn't warrent having a cache. Furthermore, it's quite flaky, too. E.g. running it twice in succession produces the following results: Test master pks-reftx-hook-remove-cache -------------------------------------------------------------------------- 1400.2: update-ref 2.79(2.16+0.74) 2.73(2.12+0.71) -2.2% 1400.3: update-ref --stdin 0.22(0.08+0.14) 0.21(0.08+0.12) -4.5% Test master pks-reftx-hook-remove-cache -------------------------------------------------------------------------- 1400.2: update-ref 2.70(2.09+0.72) 2.74(2.13+0.71) +1.5% 1400.3: update-ref --stdin 0.21(0.10+0.10) 0.21(0.08+0.13) +0.0% One case notably absent from those benchmarks is a single executable searching for the hook hundreds of times, which is exactly the case for which the negative cache was added. p1400.2 will spawn a new update-ref for each transaction and p1400.3 only has a single reference-transaction for all reference updates. So this commit adds a third benchmark, which performs an non-atomic push of a thousand references. This will create a new reference transaction per reference. But even for this case, the negative cache doesn't consistently improve performance: Test master pks-reftx-hook-remove-cache -------------------------------------------------------------------------- 1400.4: nonatomic push 6.63(6.50+0.13) 6.81(6.67+0.14) +2.7% 1400.4: nonatomic push 6.35(6.21+0.14) 6.39(6.23+0.16) +0.6% 1400.4: nonatomic push 6.43(6.31+0.13) 6.42(6.28+0.15) -0.2% So let's just remove the cache altogether to simplify the code. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-21p5302: count up to online-cpus for thread testsJeff King1-23/+24
When PERF_EXTRA is enabled, p5302 checks the performance of index-pack with various numbers of threads. This can be useful for deciding what the default should be (which is currently capped at 3 threads based on the results of this script). However, we only go up to 8 threads, and modern machines may have more. Let's get the number of CPUs from test-tool, and test various numbers of threads between one and that maximum. Note that the current tests aren't all identical, as we have to set GIT_FORCE_THREADS for the --threads=1 test (which measures the overhead of starting a single worker thread versus the "0" case of using the main thread). To keep the loop simple, we'll keep the "0" case out of it, and set GIT_FORCE_THREADS=1 for all of the other cases (it's a noop for all but the "1" case, since numbers higher than 1 would always need threads). Note also that we could skip running "test-tool" if PERF_EXTRA isn't set. However, there's some small value in knowing the number of threads, so that we can mark each test as skipped in the output. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>