Skip to content

Port "builtin/add: enable fscache around repo_read_index_preload" to vfs-2.54.0#902

Merged
dscho merged 2 commits intomicrosoft:vfs-2.54.0from
tonybaloney:wsl-fscache-add
Apr 28, 2026
Merged

Port "builtin/add: enable fscache around repo_read_index_preload" to vfs-2.54.0#902
dscho merged 2 commits intomicrosoft:vfs-2.54.0from
tonybaloney:wsl-fscache-add

Conversation

@dscho
Copy link
Copy Markdown
Member

@dscho dscho commented Apr 28, 2026

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.

Anthony Shaw added 2 commits 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>
@dscho dscho requested a review from mjcheetham April 28, 2026 13:31
@dscho dscho self-assigned this Apr 28, 2026
@dscho dscho merged commit 6d20654 into microsoft:vfs-2.54.0 Apr 28, 2026
310 of 316 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant