windows - git stash 在 Windows 上运行缓慢

Question

在我的 Windows 机器上，git stash 每次调用都有大约 3.5 秒的开销，这使我的 git 提交 Hook 增加了大约 7 秒。

linux下(同一台机器)相同的命令大约需要0.01秒。性能问题也适用于空存储库。

我已经尝试了来自 this thread 的以下内容和 this thread :

• core.fscache 设置为 true
• core.preloadindex 设置为 true
• gc.auto 设置为 256
• 设置 PS1='$'
• 在管理模式下运行 cmd
• 在 cmd.exe 而不是 git-bash 中运行

运行 GIT_TRACE=true git stash list

16:58:16.844591 git.c:563               trace: exec: 'git-stash' 'list'
16:58:16.844591 run-command.c:336       trace: run_command: 'git-stash' 'list'
16:58:19.699591 git.c:350               trace: built-in: git 'rev-parse' '--git-dir'
16:58:19.859591 git.c:350               trace: built-in: git 'rev-parse' '--git-path' 'objects'
16:58:20.069591 git.c:350               trace: built-in: git 'rev-parse' '--show-toplevel'
16:58:20.154591 git.c:350               trace: built-in: git 'rev-parse' '--git-path' 'index'
16:58:20.244591 git.c:350               trace: built-in: git 'config' '--get-colorbool' 'color.interactive'
16:58:20.334591 git.c:350               trace: built-in: git 'config' '--get-color' 'color.interactive.help' 'red bold'
16:58:20.424591 git.c:350               trace: built-in: git 'config' '--get-color' '' 'reset'
16:58:20.514591 git.c:350               trace: built-in: git 'rev-parse' '--verify' '--quiet' 'refs/stash'

real    0m3.845s
user    0m0.000s
sys     0m0.047s

运行 GIT_TRACE_PERFORMANCE=true git stash list

16:59:18.414591 trace.c:420             performance: 0.001078046 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-dir'                                          
16:59:18.569591 trace.c:420             performance: 0.000947184 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-path' 'objects'                               
16:59:18.779591 trace.c:420             performance: 0.001253627 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--show-toplevel'                                    
16:59:18.869591 trace.c:420             performance: 0.001285517 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-path' 'index'                                 
16:59:18.955591 trace.c:420             performance: 0.001139994 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-colorbool' 'color.interactive'                   
16:59:19.040591 trace.c:420             performance: 0.001182881 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-color' 'color.interactive.help' 'red bold'       
16:59:19.125591 trace.c:420             performance: 0.001128997 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-color' '' 'reset'                                
16:59:19.215591 trace.c:420             performance: 0.001567766 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--verify' '--quiet' 'refs/stash'                    
16:59:19.295591 trace.c:420             performance: 3.730583540 s: git command: 'C:\Program Files\Git\mingw64\bin\git.exe' 'stash' 'list'                                                                

real    0m3.819s                                                                                                                                                                                          
user    0m0.000s                                                                                                                                                                                          
sys     0m0.062s                                                                                                                                                                                          

从日志中我们看到，在运行 git-stash 命令和运行 git-rev-parse 之间大约需要 3 秒。我可以运行任何其他标志来查找瓶颈吗？

Answer 1

与 Git for Windows 2.19 (2018 年 9 月)，git stash(和 git rebase)不再是纯脚本，而是使用 git.exe 编译的二进制文件.
参见 git-for-windows/build-extra PR 203 .

要激活它们，输入:

git config --global rebase.useBuiltin true
git config --global stash.useBuiltin true

警告:

As nice as the speed-ups are, the patches in question are still in flux, and they are not battle-tested at all.

所以，目前 git stash 的脚本版本仍然是默认的，这样:

• users who want the raw speed improvement we got through three Google Summer of Code projects working in parallel can have that,
• while others who are reluctant to play guinea pig by running only well-tested code can stay on the safe side.

重点仍然是:在下一个版本的 Git 中，git-stash 的 bash 脚本最终会消失，并且它的替代品会更快。

注意:下一个版本将是 Git 2.27(2020 年第 2 季度):“git stash”保留了一个逃生 channel ，以便在几个版本中使用脚本版本，但它已经过时了。

它已被删除。

参见 commit 8a2cd3f , commit b0c7362 (2020 年 3 月 3 日)作者:Thomas Gummerer (tgummerer) .
^{(由 Junio C Hamano -- gitster -- merge 于 commit 369ae75，2020 年 3 月 27 日)}

stash: remove the stash.useBuiltin setting

^{Signed-off-by: Thomas Gummerer}

Remove the stash.useBuiltin setting which was added as an escape hatch to disable the builtin version of stash first released with Git 2.22.

Carrying the legacy version is a maintenance burden, and has in fact become out of date failing a test since the 2.23 release, without anyone noticing until now.

So users would be getting a hint to fall back to a potentially buggy version of the tool.

We used to shell out to git config to get the useBuiltin configuration to avoid changing any global state before spawning legacy-stash.
However that is no longer necessary, so just use the 'git_config' function to get the setting instead.

Similar to what we've done in d03ebd411c ("rebase: remove the rebase.useBuiltin setting", 2019-03-18, Git v2.22.0-rc0 -- merge listed in batch #5), where we remove the corresponding setting for rebase, we leave the documentation in place, so people can refer back to it when searching for it online, and so we can refer to it in the commit message.

---

2019 年第二季度更新，使用 Git 2.22，git stash 完全用 C 重写。²参见 commit 40af146 , commit 48ee24a , commit ef0f0b4 , commit 64fe9c2 , commit 1ac528c , commit d553f53 , commit d4788af , commit 41e0dd5 , commit dc7bd38 , commit 130f269 , commit bef55dc , commit dac566c , commit ab8ad46 (2019 年 2 月 25 日)Paul-Sebastian Ungureanu (weekly-digest[bot]) .
参见 commit c4de61d , commit 577c199 , commit 4e2dd39 , commit 8a0fc8d (2019 年 2 月 25 日)Joel Teichroeb (klusark) .
参见 commit 7906af0 , commit 90a4627 , commit 8d8e9c2 (2019 年 2 月 25 日)Johannes Schindelin (dscho) .
^{(由 Junio C Hamano -- gitster -- merge 于 commit e36adf7 ，2019 年 4 月 22 日)}

您仍然可以 use the shell script with git legacy-stash .

和:

stash: convert stash--helper.c into stash.c

The old shell script git-stash.sh was removed and replaced entirely by builtin/stash.c.
In order to do that, create and push were adapted to work without stash.sh.

For example, before this commit, git stash create called git stash--helper create --message "$*". If it called git stash--helper create "$@", thensome of these changes wouldn't have been necessary.

This commit also removes the word helper since now stash iscalled directly and not by a shell script.

有优化:

stash: optimize get_untracked_files() and check_changes()

This commits introduces a optimization by avoiding calling thesame functions again.
For example, git stash push -u would call at some points the following functions:

• check_changes() (inside do_push_stash())
• do_create_stash(), which calls: check_changes() andget_untracked_files()

Note that check_changes() also calls get_untracked_files().
So, check_changes() is called 2 times and get_untracked_files()3 times.

The old function check_changes() now consists of two functions:get_untracked_files() and check_changes_tracked_files().

These are the call chains for push and create:

• push_stash() -> do_push_stash() -> do_create_stash()
• create_stash() -> do_create_stash()

To prevent calling the same functions over and over again, check_changes() inside do_create_stash() is now placed in the caller functions (create_stash() and do_push_stash()).
This way check_changes() and get_untracked files() are calledonly one time.

---

在 Git 2.36(2022 年第 2 季度)中，警告“the stash.useBuiltin support has been removed!”的删除终于完成了!

参见 commit e9b272e , commit deeaf5e , commit 5d4dc38 , commit 6de0722 (2022 年 1 月 27 日)Johannes Schindelin (dscho) .
^{(由 Junio C Hamano -- gitster -- merge 于 commit b9f791a ，2022 年 2 月 16 日)}

stash: stop warning about the obsolete stash.useBuiltin config setting

^{Signed-off-by: Johannes Schindelin}

In 8a2cd3f ("stash: remove the stash.useBuiltin setting", 2020-03-03, Git v2.27.0-rc0 -- merge listed in batch #2), we removed support for stash.useBuiltin, but left a warning in its place.

After almost two years, and several major versions, it is time to remove even that warning.