t/perf: add fsmonitor perf test for git diff

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>
1 file changed
tree: 3fa8ab43ea6d48fdf81f371465178d3bc15cebd6
  1. .github/
  2. block-sha1/
  3. builtin/
  4. ci/
  5. compat/
  6. contrib/
  7. Documentation/
  8. ewah/
  9. git-gui/
  10. gitk-git/
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  14. perl/
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  23. vcs-svn/
  24. xdiff/
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  38. add-patch.c
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  79. CODE_OF_CONDUCT.md
  80. color.c
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  85. command-list.txt
  86. commit-graph.c
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  90. commit-slab-decl.h
  91. commit-slab-impl.h
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  93. commit.c
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  95. common-main.c
  96. config.c
  97. config.h
  98. config.mak.dev
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  100. config.mak.uname
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  112. csum-file.c
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  117. decorate.c
  118. decorate.h
  119. delta-islands.c
  120. delta-islands.h
  121. delta.h
  122. detect-compiler
  123. diff-delta.c
  124. diff-lib.c
  125. diff-no-index.c
  126. diff.c
  127. diff.h
  128. diffcore-break.c
  129. diffcore-delta.c
  130. diffcore-order.c
  131. diffcore-pickaxe.c
  132. diffcore-rename.c
  133. diffcore.h
  134. dir-iterator.c
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  138. editor.c
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  140. environment.c
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  143. fetch-negotiator.c
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  145. fetch-pack.c
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  147. fmt-merge-msg.c
  148. fmt-merge-msg.h
  149. fsck.c
  150. fsck.h
  151. fsmonitor.c
  152. fsmonitor.h
  153. fuzz-commit-graph.c
  154. fuzz-pack-headers.c
  155. fuzz-pack-idx.c
  156. generate-cmdlist.sh
  157. generate-configlist.sh
  158. gettext.c
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  160. git-add--interactive.perl
  161. git-archimport.perl
  162. git-bisect.sh
  163. git-compat-util.h
  164. git-cvsexportcommit.perl
  165. git-cvsimport.perl
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  167. git-difftool--helper.sh
  168. git-filter-branch.sh
  169. git-instaweb.sh
  170. git-merge-octopus.sh
  171. git-merge-one-file.sh
  172. git-merge-resolve.sh
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  175. git-p4.py
  176. git-parse-remote.sh
  177. git-quiltimport.sh
  178. git-rebase--preserve-merges.sh
  179. git-request-pull.sh
  180. git-send-email.perl
  181. git-sh-i18n.sh
  182. git-sh-setup.sh
  183. git-submodule.sh
  184. git-svn.perl
  185. GIT-VERSION-GEN
  186. git-web--browse.sh
  187. git.c
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  189. gpg-interface.c
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  209. INSTALL
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  211. json-writer.c
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  213. khash.h
  214. kwset.c
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  216. levenshtein.c
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  226. list-objects-filter-options.h
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  231. list.h
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  240. mailinfo.c
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  243. mailmap.h
  244. Makefile
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  246. mem-pool.c
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  248. merge-blobs.c
  249. merge-blobs.h
  250. merge-recursive.c
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  255. midx.c
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  257. name-hash.c
  258. notes-cache.c
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  260. notes-merge.c
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  271. oidmap.c
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  273. oidset.c
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  275. pack-bitmap-write.c
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  277. pack-bitmap.h
  278. pack-check.c
  279. pack-objects.c
  280. pack-objects.h
  281. pack-revindex.c
  282. pack-revindex.h
  283. pack-write.c
  284. pack.h
  285. packfile.c
  286. packfile.h
  287. pager.c
  288. parse-options-cb.c
  289. parse-options.c
  290. parse-options.h
  291. patch-delta.c
  292. patch-ids.c
  293. patch-ids.h
  294. path.c
  295. path.h
  296. pathspec.c
  297. pathspec.h
  298. pkt-line.c
  299. pkt-line.h
  300. preload-index.c
  301. pretty.c
  302. pretty.h
  303. prio-queue.c
  304. prio-queue.h
  305. progress.c
  306. progress.h
  307. promisor-remote.c
  308. promisor-remote.h
  309. prompt.c
  310. prompt.h
  311. protocol.c
  312. protocol.h
  313. prune-packed.c
  314. prune-packed.h
  315. quote.c
  316. quote.h
  317. range-diff.c
  318. range-diff.h
  319. reachable.c
  320. reachable.h
  321. read-cache.c
  322. README.md
  323. rebase-interactive.c
  324. rebase-interactive.h
  325. rebase.c
  326. rebase.h
  327. ref-filter.c
  328. ref-filter.h
  329. reflog-walk.c
  330. reflog-walk.h
  331. refs.c
  332. refs.h
  333. refspec.c
  334. refspec.h
  335. remote-curl.c
  336. remote.c
  337. remote.h
  338. replace-object.c
  339. replace-object.h
  340. repo-settings.c
  341. repository.c
  342. repository.h
  343. rerere.c
  344. rerere.h
  345. reset.c
  346. reset.h
  347. resolve-undo.c
  348. resolve-undo.h
  349. revision.c
  350. revision.h
  351. run-command.c
  352. run-command.h
  353. send-pack.c
  354. send-pack.h
  355. sequencer.c
  356. sequencer.h
  357. serve.c
  358. serve.h
  359. server-info.c
  360. setup.c
  361. sh-i18n--envsubst.c
  362. sha1-file.c
  363. sha1-lookup.c
  364. sha1-lookup.h
  365. sha1-name.c
  366. sha1dc_git.c
  367. sha1dc_git.h
  368. shallow.c
  369. shallow.h
  370. shell.c
  371. shortlog.h
  372. sideband.c
  373. sideband.h
  374. sigchain.c
  375. sigchain.h
  376. split-index.c
  377. split-index.h
  378. stable-qsort.c
  379. strbuf.c
  380. strbuf.h
  381. streaming.c
  382. streaming.h
  383. string-list.c
  384. string-list.h
  385. strvec.c
  386. strvec.h
  387. sub-process.c
  388. sub-process.h
  389. submodule-config.c
  390. submodule-config.h
  391. submodule.c
  392. submodule.h
  393. symlinks.c
  394. tag.c
  395. tag.h
  396. tar.h
  397. tempfile.c
  398. tempfile.h
  399. thread-utils.c
  400. thread-utils.h
  401. tmp-objdir.c
  402. tmp-objdir.h
  403. trace.c
  404. trace.h
  405. trace2.c
  406. trace2.h
  407. trailer.c
  408. trailer.h
  409. transport-helper.c
  410. transport-internal.h
  411. transport.c
  412. transport.h
  413. tree-diff.c
  414. tree-walk.c
  415. tree-walk.h
  416. tree.c
  417. tree.h
  418. unicode-width.h
  419. unimplemented.sh
  420. unix-socket.c
  421. unix-socket.h
  422. unpack-trees.c
  423. unpack-trees.h
  424. upload-pack.c
  425. upload-pack.h
  426. url.c
  427. url.h
  428. urlmatch.c
  429. urlmatch.h
  430. usage.c
  431. userdiff.c
  432. userdiff.h
  433. utf8.c
  434. utf8.h
  435. varint.c
  436. varint.h
  437. version.c
  438. version.h
  439. versioncmp.c
  440. walker.c
  441. walker.h
  442. wildmatch.c
  443. wildmatch.h
  444. worktree.c
  445. worktree.h
  446. wrap-for-bin.sh
  447. wrapper.c
  448. write-or-die.c
  449. ws.c
  450. wt-status.c
  451. wt-status.h
  452. xdiff-interface.c
  453. xdiff-interface.h
  454. zlib.c
README.md

Build status

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-<commandname>.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission). To subscribe to the list, send an email with just “subscribe git” in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.

Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.

The maintainer frequently sends the “What's cooking” reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name “git” was given by Linus Torvalds when he wrote the very first version. He described the tool as “the stupid content tracker” and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of “get” may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • “global information tracker”: you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • “goddamn idiotic truckload of sh*t”: when it breaks