builtin/add: enable fscache around repo_read_index_preload#899
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dscho
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Apr 28, 2026
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I will split the commit a bit, and "forge" your SOB.
| enable_fscache(0); | ||
| /* We do not really re-read the index but update the up-to-date flags */ | ||
| preload_index(repo->index, &pathspec, 0); | ||
|
|
| dir_clear(&dir); | ||
| clear_pathspec(&pathspec); | ||
| enable_fscache(0); | ||
| disable_fscache(); |
| die_in_unpopulated_submodule(repo->index, prefix); | ||
| die_path_inside_submodule(repo->index, &pathspec); | ||
|
|
||
| enable_fscache(0); |
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April 28, 2026 09:40
Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest `lstat()`-bound work in `git add` happens inside `repo_read_index_preload()`, which currently runs *before* `enable_fscache()` is called. Moving the enable up so the preload phase is wrapped lets the existing batched `NtQueryDirectoryFile()` cache cover the bulk of the lstat traffic. Signed-off-by: Anthony Shaw <anthonyshaw@microsoft.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix a copy-paste bug at the end of `cmd_add()`: the cleanup site called `enable_fscache(0)` again instead of `disable_fscache()`, leaking the refcount. Harmless in a one-shot process today, but it confuses the matching enable/disable contract that callers and reviewers expect. Signed-off-by: Anthony Shaw <anthonyshaw@microsoft.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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I will fix the |
This was referenced Apr 28, 2026
dscho
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Apr 28, 2026
…`vfs-2.54.0` (#902) This is a companion of #899 and git-for-windows#6216. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
dscho
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Jun 5, 2026
This is a companion of microsoft#899. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
gitforwindowshelper Bot
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Jun 10, 2026
This is a companion of microsoft#899. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
gitforwindowshelper Bot
pushed a commit
to git-for-windows/git
that referenced
this pull request
Jun 10, 2026
This is a companion of microsoft#899. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
gitforwindowshelper Bot
pushed a commit
to git-for-windows/git
that referenced
this pull request
Jun 10, 2026
This is a companion of microsoft#899. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
gitforwindowshelper Bot
pushed a commit
to git-for-windows/git
that referenced
this pull request
Jun 11, 2026
This is a companion of microsoft#899. Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in git add happens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add. Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.
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Trace2 + GIT_TRACE_FSCACHE evidence on Windows ARM64 (Snapdragon X Elite, ReFS Dev Drive) shows that the heaviest lstat-bound work in
git addhappens inside repo_read_index_preload(), which currently runs before enable_fscache() is called. Moving the enable up so the preload phase is wrapped lets the existing batched NtQueryDirectoryFile cache cover the bulk of the lstat traffic. This patch gave me a ~30% performance improvement on a large git repo with a batched add.Also at the end of cmd_add(): the cleanup site called enable_fscache(0) again instead of disable_fscache(), leaking the refcount.