This is retry of #1419.
I added flush_fscache macro to flush cached stats after disk writing
with tests for regression reported in #1438 and #1442.
git checkout checks each file path in sorted order, so cache flushing does not
make performance worse unless we have large number of modified files in
a directory containing many files.
Using chromium repository, I tested `git checkout .` performance when I
delete 10 files in different directories.
With this patch:
TotalSeconds: 4.307272
TotalSeconds: 4.4863595
TotalSeconds: 4.2975562
Avg: 4.36372923333333
Without this patch:
TotalSeconds: 20.9705431
TotalSeconds: 22.4867685
TotalSeconds: 18.8968292
Avg: 20.7847136
I confirmed this patch passed all tests in t/ with core_fscache=1.
Signed-off-by: Takuto Ikuta <tikuta@chromium.org>
When I do git fetch, git call file stats under .git/objects for each
refs. This takes time when there are many refs.
By enabling fscache, git takes file stats by directory traversing and that
improved the speed of fetch-pack for repository having large number of
refs.
In my windows workstation, this improves the time of `git fetch` for
chromium repository like below. I took stats 3 times.
* With this patch
TotalSeconds: 9.9825165
TotalSeconds: 9.1862075
TotalSeconds: 10.1956256
Avg: 9.78811653333333
* Without this patch
TotalSeconds: 15.8406702
TotalSeconds: 15.6248053
TotalSeconds: 15.2085938
Avg: 15.5580231
Signed-off-by: Takuto Ikuta <tikuta@chromium.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix regression described in:
https://github.com/git-for-windows/git/issues/1392
which was introduced in:
b2353379bb
Problem Symptoms
================
When the user has a .gitignore file that is a symlink, the fscache
optimization introduced above caused the stat-data from the symlink,
rather that of the target file, to be returned. Later when the ignore
file was read, the buffer length did not match the stat.st_size field
and we called die("cannot use <path> as an exclude file")
Optimization Rationale
======================
The above optimization calls lstat() before open() primarily to ask
fscache if the file exists. It gets the current stat-data as a side
effect essentially for free (since we already have it in memory).
If the file does not exist, it does not need to call open(). And
since very few directories have .gitignore files, we can greatly
reduce time spent in the filesystem.
Discussion of Fix
=================
The above optimization calls lstat() rather than stat() because the
fscache only intercepts lstat() calls. Calls to stat() stay directed
to the mingw_stat() completly bypassing fscache. Furthermore, calls
to mingw_stat() always call {open, fstat, close} so that symlinks are
properly dereferenced, which adds *additional* open/close calls on top
of what the original code in dir.c is doing.
Since the problem only manifests for symlinks, we add code to overwrite
the stat-data when the path is a symlink. This preserves the effect of
the performance gains provided by the fscache in the normal case.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Make fscache_enabled() function public rather than static.
Remove unneeded fscache_is_enabled() function.
Change is_fscache_enabled() macro to call fscache_enabled().
is_fscache_enabled() now takes a pathname so that the answer
is more precise and mean "is fscache enabled for this pathname",
since fscache only stores repo-relative paths and not absolute
paths, we can avoid attempting lookups for absolute paths.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach read_directory_recursive() and add_excludes() to
be aware of optional fscache and avoid trying to open()
and fstat() non-existant ".gitignore" files in every
directory in the worktree.
The current code in add_excludes() calls open() and then
fstat() for a ".gitignore" file in each directory present
in the worktree. Change that when fscache is enabled to
call lstat() first and if present, call open().
This seems backwards because both lstat needs to do more
work than fstat. But when fscache is enabled, fscache will
already know if the .gitignore file exists and can completely
avoid the IO calls. This works because of the lstat diversion
to mingw_lstat when fscache is enabled.
This reduced status times on a 350K file enlistment of the
Windows repo on a NVMe SSD by 0.25 seconds.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach "add" to use preload-index and fscache features
to improve performance on very large repositories.
During an "add", a call is made to run_diff_files()
which calls check_remove() for each index-entry. This
calls lstat(). On Windows, the fscache code intercepts
the lstat() calls and builds a private cache using the
FindFirst/FindNext routines, which are much faster.
Somewhat independent of this, is the preload-index code
which distributes some of the start-up costs across
multiple threads.
We need to keep the call to read_cache() before parsing the
pathspecs (and hence cannot use the pathspecs to limit any preload)
because parse_pathspec() is using the index to determine whether a
pathspec is, in fact, in a submodule. If we would not read the index
first, parse_pathspec() would not error out on a path that is inside
a submodule, and t7400-submodule-basic.sh would fail with
not ok 47 - do not add files from a submodule
We still want the nice preload performance boost, though, so we simply
call read_cache_preload(&pathspecs) after parsing the pathspecs.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Teach FSCACHE to remember "not found" directories.
This is a performance optimization.
FSCACHE is a performance optimization available for Windows. It
intercepts Posix-style lstat() calls into an in-memory directory
using FindFirst/FindNext. It improves performance on Windows by
catching the first lstat() call in a directory, using FindFirst/
FindNext to read the list of files (and attribute data) for the
entire directory into the cache, and short-cut subsequent lstat()
calls in the same directory. This gives a major performance
boost on Windows.
However, it does not remember "not found" directories. When STATUS
runs and there are missing directories, the lstat() interception
fails to find the parent directory and simply return ENOENT for the
file -- it does not remember that the FindFirst on the directory
failed. Thus subsequent lstat() calls in the same directory, each
re-attempt the FindFirst. This completely defeats any performance
gains.
This can be seen by doing a sparse-checkout on a large repo and
then doing a read-tree to reset the skip-worktree bits and then
running status.
This change reduced status times for my very large repo by 60%.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
If multiple threads access a directory that is not yet in the cache, the
directory will be loaded by each thread. Only one of the results is added
to the cache, all others are leaked. This wastes performance and memory.
On cache miss, add a future object to the cache to indicate that the
directory is currently being loaded. Subsequent threads register themselves
with the future object and wait. When the first thread has loaded the
directory, it replaces the future object with the result and notifies
waiting threads.
Signed-off-by: Karsten Blees <blees@dcon.de>
Checking the work tree status is quite slow on Windows, due to slow
`lstat()` emulation (git calls `lstat()` once for each file in the
index). Windows operating system APIs seem to be much better at scanning
the status of entire directories than checking single files.
Add an `lstat()` implementation that uses a cache for lstat data. Cache
misses read the entire parent directory and add it to the cache.
Subsequent `lstat()` calls for the same directory are served directly
from the cache.
Also implement `opendir()`/`readdir()`/`closedir()` so that they create
and use directory listings in the cache.
The cache doesn't track file system changes and doesn't plug into any
modifying file APIs, so it has to be explicitly enabled for git functions
that don't modify the working copy.
Note: in an earlier version of this patch, the cache was always active and
tracked file system changes via ReadDirectoryChangesW. However, this was
much more complex and had negative impact on the performance of modifying
git commands such as 'git checkout'.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Add a macro to mark code sections that only read from the file system,
along with a config option and documentation.
This facilitates implementation of relatively simple file system level
caches without the need to synchronize with the file system.
Enable read-only sections for 'git status' and preload_index.
Signed-off-by: Karsten Blees <blees@dcon.de>
Emulating the POSIX lstat API on Windows via GetFileAttributes[Ex] is quite
slow. Windows operating system APIs seem to be much better at scanning the
status of entire directories than checking single files. A caching
implementation may improve performance by bulk-reading entire directories
or reusing data obtained via opendir / readdir.
Make the lstat implementation pluggable so that it can be switched at
runtime, e.g. based on a config option.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Emulating the POSIX `dirent` API on Windows via
`FindFirstFile()`/`FindNextFile()` is pretty staightforward, however,
most of the information provided in the `WIN32_FIND_DATA` structure is
thrown away in the process. A more sophisticated implementation may
cache this data, e.g. for later reuse in calls to `lstat()`.
Make the `dirent` implementation pluggable so that it can be switched at
runtime, e.g. based on a config option.
Define a base DIR structure with pointers to `readdir()`/`closedir()`
that match the `opendir()` implementation (similar to vtable pointers in
Object-Oriented Programming). Define `readdir()`/`closedir()` so that
they call the function pointers in the `DIR` structure. This allows to
choose the `opendir()` implementation on a call-by-call basis.
Make the fixed-size `dirent.d_name` buffer a flex array, as `d_name` may
be implementation specific (e.g. a caching implementation may allocate a
`struct dirent` with _just_ the size needed to hold the `d_name` in
question).
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We will use them in the upcoming "FSCache" patches (to accelerate
sequential lstat() calls).
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Historically, the macOS jobs have always been among the longest-running
ones, and recently the `git p4` tests became another liability: They
started to fail much more often (maybe as of the switch away from the
`macos-13` pool?), requiring re-runs of the jobs that already were
responsible for long CI build times.
Of the 35 test scripts that exercise `git p4`, 32 are actually run on
macOS (3 are skipped for reasons like case-sensitivee filesystem), and
they take an accumulated runtime of over half an hour.
Furthermore, the `git p4` command is not really affected by Git for
Windows' patches, at least not as far as macOS is concerned, therefore
it is not only causing developer friction to have these long-running,
frequently failing tests, it is also quite wasteful: There has not been
a single instance so far where any `git p4` test failure in Git for
Windows had demonstrated an actionable bug.
So let's just disable those tests in the CI runs, at least on macOS.
There have been too many challenges supporting `git svn`, including lack
of participation in developing/maintaining the required stack.
See https://github.com/git-for-windows/git/issues/5405 for full details.
Historically, the macOS jobs have always been among the longest-running
ones, and recently the `git p4` tests became another liability: They
started to fail much more often (maybe as of the switch away from the
`macos-13` pool?), requiring re-runs of the jobs that already were
responsible for long CI build times.
Of the 35 test scripts that exercise `git p4`, 32 are actually run on
macOS (3 are skipped for reasons like case-sensitivee filesystem), and
they take an accumulated runtime of over half an hour.
Furthermore, the `git p4` command is not really affected by Git for
Windows' patches, at least not as far as macOS is concerned, therefore
it is not only causing developer friction to have these long-running,
frequently failing tests, it is also quite wasteful: There has not been
a single instance so far where any `git p4` test failure in Git for
Windows had demonstrated an actionable bug.
While upstream Git is confident to have addressed the flakiness of the
`git p4` tests via ffff0bb0dac1 (Use Perforce arm64 binary on macOS CI
jobs, 2025-11-16) (which got slipped in at the 11th hour into the
v2.52.0 release, fast-tracked without ever hitting `seen` even after
-rc2 was released), I am not quite so confident, and besides, the
runtime penalty of running those tests in Git for Windows' CI runs is
still a worrisome burden.
So let's just disable those tests in the CI runs, at least on macOS.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the branch thicket of patches in Git for Windows that are
considered ready for upstream. To keep them in a ready-to-submit shape,
they are kept as close to the beginning of the branch thicket as
possible.
There have been too many challenges supporting `git svn`, including lack
of participation in developing/maintaining the required stack.
See https://github.com/git-for-windows/git/issues/5405 for full details.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
To avoid `check-whitespace` failures when rebasing Git for Windows onto
new Git versions, let's limit that job's scope to downstream commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This introduces `git survey` to Git for Windows ahead of upstream for
the express purpose of getting the path-based analysis in the hands of
more folks.
The inspiration of this builtin is
[`git-sizer`](https://github.com/github/git-sizer), but since that
command relies on `git cat-file --batch` to get the contents of objects,
it has limits to how much information it can provide.
This is mostly a rewrite of the `git survey` builtin that was introduced
into the `microsoft/git` fork in microsoft/git#667. That version had a
lot more bells and whistles, including an analysis much closer to what
`git-sizer` provides.
The biggest difference in this version is that this one is focused on
using the path-walk API in order to visit batches of objects based on a
common path. This allows identifying, for instance, the path that is
contributing the most to the on-disk size across all versions at that
path.
For example, here are the top ten paths contributing to my local Git
repository (which includes `microsoft/git` and `gitster/git`):
```
TOP FILES BY DISK SIZE
============================================================================
Path | Count | Disk Size | Inflated Size
-----------------------------------------+-------+-----------+--------------
whats-cooking.txt | 1373 | 11637459 | 37226854
t/helper/test-gvfs-protocol | 2 | 6847105 | 17233072
git-rebase--helper | 1 | 6027849 | 15269664
compat/mingw.c | 6111 | 5194453 | 463466970
t/helper/test-parse-options | 1 | 3420385 | 8807968
t/helper/test-pkt-line | 1 | 3408661 | 8778960
t/helper/test-dump-untracked-cache | 1 | 3408645 | 8780816
t/helper/test-dump-fsmonitor | 1 | 3406639 | 8776656
po/vi.po | 104 | 1376337 | 51441603
po/de.po | 210 | 1360112 | 71198603
```
This kind of analysis has been helpful in identifying the reasons for
growth in a few internal monorepos. Those findings motivated the changes
in #5157 and #5171.
With this early version in Git for Windows, we can expand the reach of
the experimental tool in advance of it being contributed to the upstream
project.
Unfortunately, this will mean that in the next `microsoft/git` rebase,
Jeff Hostetler's version will need to be pulled out since there are
enough conflicts. These conflicts include how tables are stored and
generated, as the version in this PR is slightly more general to allow
for different kinds of data.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is a follow up to #5157 as well as motivated by the RFC in
gitgitgadget/git#1786.
We have ways of walking all objects, but it is focused on visiting a
single commit and then expanding the new trees and blobs reachable from
that commit that have not been visited yet. This means that objects
arrive without any locality based on their path.
Add a new "path walk API" that focuses on walking objects in batches
according to their type and path. This will walk all annotated tags, all
commits, all root trees, and then start a depth-first search among all
paths in the repo to collect trees and blobs in batches.
The most important application for this is being fast-tracked to Git for
Windows: `git pack-objects --path-walk`. This application of the path
walk API discovers the objects to pack via this batched walk, and
automatically groups objects that appear at a common path so they can be
checked for delta comparisons.
This use completely avoids any name-hash collisions (even the collisions
that sometimes occur with the new `--full-name-hash` option) and can be
much faster to compute since the first pass of delta calculations does
not waste time on objects that are unlikely to be diffable.
Some statistics are available in the commit messages.
This is an updated version of gitgitgadget/git#1785, intended for early
consumption into Git for Windows.
The idea here is to add a new `--full-name-hash` option to `git
pack-objects` and `git repack`. This adjusts the name-hash value used
for finding delta bases in such a way that uses the full path name with
a lower likelihood of collisions than the default name-hash algorithm.
In many repositories with name-hash collisions and many versions of
those paths, this can significantly reduce the size of a full repack. It
can also help in certain cases of `git push`, but only if the pack is
already artificially inflated by name-hash collisions; cases that find
"sibling" deltas as better choices become worse with `--full-name-hash`.
Thus, this option is currently recommended for full repacks of large
repos, and on client machines without reachability bitmaps.
Some care is taken to ignore this option when using bitmaps, either
writing bitmaps or using a bitmap walk during reads. The bitmap file
format contains name-hash values, but no way to indicate which function
is used, so compatibility is a concern for bitmaps. Future work could
explore this idea.
After this PR is merged, then the more-involved `--path-walk` option may
be considered.
Since Git LFS v3.5.x implicitly dropped Windows 7 support, we now want
users to be advised _what_ is going wrong on that Windows version. This
topic branch goes out of its way to provide users with such guidance.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch adds support for a more Windows-native user-wide
config file than `XDG_CONFIG_HOME` (or `~/.config/`) will ever be.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch contains a patch that made it into Git for Windows
v2.45.1 but not into Git v2.45.1 (because the latter does not come with
symlink support on Windows).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Another (hopefully clean) PR for showing the error warning about atomic
append on windows after failure on APFS, which returns EBADF not EINVAL.
Signed-off-by: David Lomas <dl3@pale-eds.co.uk>
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
This patch adds a GitHub workflow (to be triggered manually) to allow
for conveniently verifying that Git and Scalar still work as intended in
Windows Nano Server (a relatively small container base image that is
frequently used where a "small Windows" is needed, e.g. in automation
;-))
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
As per
https://github.com/git-for-windows/git/issues/4350#issuecomment-1485041503,
the major block for upgrading Git for Windows' OpenSSL from v1.1 to v3
is the tricky part where such an upgrade would break `git fetch`/`git
clone` and `git push` because the libcurl depends on the OpenSSL DLL,
and the major version bump will _change_ the file name of said DLL.
To overcome that, the plan is to build libcurl flavors for each
supported SSL/TLS backend, aligning with the way MSYS2 builds libcurl,
then switch Git for Windows' SDK to the Secure Channel-flavored libcurl,
and teach Git to look for the specific flavor of libcurl corresponding
to the `http.sslBackend` setting (if that was configured).
Here is the PR to teach Git that trick.
Every once in a while, there are bug reports in Git for Windows' bug
tracker that describe an issue running [inside MSYS2
proper](https://gitforwindows.org/install-inside-msys2-proper), totally
ignoring the big, honking warning on top of [the
page](https://gitforwindows.org/install-inside-msys2-proper) that spells
out clearly that this is an unsupported use case.
At the same time, we cannot easily deflect and say "just use MSYS2
directly" (and leave the "and stop pestering us" out). We cannot do that
because there is only an _MSYS_ `git` package in MSYS2 (i.e. a Git that
uses the quite slow POSIX emulation layer provided by the MSYS2
runtime), but no `mingw-w64-git` package (which would be equivalent in
speed to Git for Windows).
In https://github.com/msys2/MINGW-packages/pull/26470, I am preparing to
change that. As part of that PR, I noticed and fixed a couple of issues
_in `git-for-windows/git` that prevented full support for
`mingw-w64-git` in MSYS2, such as problems with CLANG64 and UCRT64.
While at it, I simplified the entire setup to trust MSYS2's
`MINGW_PREFIX` & related environment variables instead of hard-coding
values like the installation prefix and what `MSYSTEM` to fall back on
if it is unset.
It is merely a historical wart that, say, `git-commit` exists in the
`libexec/git-core/` directory, a tribute to the original idea to let Git
be essentially a bunch of Unix shell scripts revolving around very few
"plumbing" (AKA low-level) commands.
Git has evolved a lot from there. These days, most of Git's
functionality is contained within the `git` executable, in the form of
"built-in" commands.
To accommodate for scripts that use the "dashed" form of Git commands,
even today, Git provides hard-links that make the `git` executable
available as, say, `git-commit`, just in case that an old script has not
been updated to invoke `git commit`.
Those hard-links do not come cheap: they take about half a minute for
every build of Git on Windows, they are mistaken for taking up huge
amounts of space by some Windows Explorer versions that do not
understand hard-links, and therefore many a "bug" report had to be
addressed.
The "dashed form" has been officially deprecated in Git version 1.5.4,
which was released on February 2nd, 2008, i.e. a very long time ago.
This deprecation was never finalized by skipping these hard-links, but
we can start the process now, in Git for Windows.
This addresses the concern raised in
https://github.com/git-for-windows/git/pull/4185#discussion_r1051661894
It is checked for w.r.t. global repository struct down in the callstack
in compatibility layer for MinGW before being assigned in the function
that `free()`'d it.
Add `FileVersion`, which is a required string ([Microsoft
documentation](https://learn.microsoft.com/en-us/windows/win32/menurc/versioninfo-resource))
in the `StringFileInfo` block.
As not all required strings were present in the block, none were being
included.
Fixes#4090
After including the `FileVersion` string, all other defined strings are
now being included on executables.
File version information for `git.exe` has changed from:
```
PS C:\Program Files\Git\bin> [System.Diagnostics.FileVersionInfo]::GetVersionInfo("C:\Data\git-sdk-64\usr\src\git\git.exe") | Select-Object *
FileVersionRaw : 2.38.1.1
ProductVersionRaw : 2.38.1.1
Comments :
CompanyName :
FileBuildPart : 1
FileDescription :
FileMajorPart : 2
FileMinorPart : 38
FileName : C:\Data\git-sdk-64\usr\src\git\git.exe
FilePrivatePart : 1
FileVersion :
InternalName :
IsDebug : False
IsPatched : False
IsPrivateBuild : False
IsPreRelease : False
IsSpecialBuild : False
Language : English (United States)
LegalCopyright :
LegalTrademarks :
OriginalFilename :
PrivateBuild :
ProductBuildPart : 1
ProductMajorPart : 2
ProductMinorPart : 38
ProductName :
ProductPrivatePart : 1
ProductVersion :
SpecialBuild :
```
To the following:
```
PS C:\Program Files\Git\bin> [System.Diagnostics.FileVersionInfo]::GetVersionInfo("C:\Data\git-sdk-64\usr\src\git\git.exe") | Select-Object *
FileVersionRaw : 2.38.1.1
ProductVersionRaw : 2.38.1.1
Comments :
CompanyName : The Git Development Community
FileBuildPart : 1
FileDescription : Git for Windows
FileMajorPart : 2
FileMinorPart : 38
FileName : C:\Data\git-sdk-64\usr\src\git\git.exe
FilePrivatePart : 1
FileVersion : 2.38.1.windows.1.10.g6ed65a6fab
InternalName : git
IsDebug : False
IsPatched : False
IsPrivateBuild : False
IsPreRelease : False
IsSpecialBuild : False
Language : English (United States)
LegalCopyright :
LegalTrademarks :
OriginalFilename : git.exe
PrivateBuild :
ProductBuildPart : 1
ProductMajorPart : 2
ProductMinorPart : 38
ProductName : Git
ProductPrivatePart : 1
ProductVersion : 2.38.1.windows.1.10.g6ed65a6fab
SpecialBuild :
```
I wasn't really expecting `GIT_VERSION` to contain the Git commit, I was
hoping for just `2.38.1` or `2.38.1.1`, at least for the `FileVersion`
string.
Anybody know if it's possible to concatenate the `MAJOR`, `MINOR`,
`MICRO`, and `PATCHLEVEL` fields with dots, or if there's another
variable that can be used (with or without `PATCHLEVEL`)?
Alternatively, use the complete `GIT_VERSION` for both `FileVersion` and
`ProductVersion`.
The first three commits are rebased versions of those in gitgitgadget/git#1215. These allow the following:
1. Fix `git config --global foo.bar <path>` from allowing the `<path>`. As a bonus, users with a config value starting with `/` will not get a warning about "old-style" paths needing a "`%(prefix)/`".
2. When in WSL, the path starts with `/` so it needs to be interpolated properly. Update the warning to include `%(prefix)/` to get the right value for WSL users. (This is specifically for using Git for Windows from Git Bash, but in a WSL directory.)
3. When using WSL, the ownership check fails and reports an error message. This is noisy, and happens even if the user has marked the path with `safe.directory`. Remove that error message.
