2 files changed, 39 insertions, 2 deletions
diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index e32404c6aa..7f69ae4855 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt
@@ -15,7 +15,8 @@ SYNOPSIS
 	[--revs [--unpacked | --all]] [--keep-pack=<pack-name>]
 	[--cruft] [--cruft-expiration=<time>]
 	[--stdout [--filter=<filter-spec>] | <base-name>]
-	[--shallow] [--keep-true-parents] [--[no-]sparse] < <object-list>
+	[--shallow] [--keep-true-parents] [--[no-]sparse]
+	[--name-hash-version=<n>] < <object-list>
 
 
 DESCRIPTION
@@ -345,6 +346,35 @@ raise an error.
 	Restrict delta matches based on "islands". See DELTA ISLANDS
 	below.
 
+--name-hash-version=<n>::
+	While performing delta compression, Git groups objects that may be
+	similar based on heuristics using the path to that object. While
+	grouping objects by an exact path match is good for paths with
+	many versions, there are benefits for finding delta pairs across
+	different full paths. Git collects objects by type and then by a
+	"name hash" of the path and then by size, hoping to group objects
+	that will compress well together.
++
+The default name hash version is `1`, which prioritizes hash locality by
+considering the final bytes of the path as providing the maximum magnitude
+to the hash function. This version excels at distinguishing short paths
+and finding renames across directories. However, the hash function depends
+primarily on the final 16 bytes of the path. If there are many paths in
+the repo that have the same final 16 bytes and differ only by parent
+directory, then this name-hash may lead to too many collisions and cause
+poor results. At the moment, this version is required when writing
+reachability bitmap files with `--write-bitmap-index`.
++
+The name hash version `2` has similar locality features as version `1`,
+except it considers each path component separately and overlays the hashes
+with a shift. This still prioritizes the final bytes of the path, but also
+"salts" the lower bits of the hash using the parent directory names. This
+method allows for some of the locality benefits of version `1` while
+breaking most of the collisions from a similarly-named file appearing in
+many different directories. At the moment, this version is not allowed
+when writing reachability bitmap files with `--write-bitmap-index` and it
+will be automatically changed to version `1`.
+
 
 DELTA ISLANDS
 -------------
diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt
index c902512a9e..5852a5c973 100644
--- a/Documentation/git-repack.txt
+++ b/Documentation/git-repack.txt
@@ -9,7 +9,9 @@ git-repack - Pack unpacked objects in a repository
 SYNOPSIS
 --------
 [verse]
-'git repack' [-a] [-A] [-d] [-f] [-F] [-l] [-n] [-q] [-b] [-m] [--window=<n>] [--depth=<n>] [--threads=<n>] [--keep-pack=<pack-name>] [--write-midx]
+'git repack' [-a] [-A] [-d] [-f] [-F] [-l] [-n] [-q] [-b] [-m]
+	[--window=<n>] [--depth=<n>] [--threads=<n>] [--keep-pack=<pack-name>]
+	[--write-midx] [--name-hash-version=<n>]
 
 DESCRIPTION
 -----------
@@ -249,6 +251,11 @@ linkgit:git-multi-pack-index[1]).
 	Write a multi-pack index (see linkgit:git-multi-pack-index[1])
 	containing the non-redundant packs.
 
+--name-hash-version=<n>::
+	Provide this argument to the underlying `git pack-objects` process.
+	See linkgit:git-pack-objects[1] for full details.
+
+
 CONFIGURATION
 -------------