From: Junio C Hamano <gitster@pobox.com>
To: "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, christian.couder@gmail.com,
johannes.schindelin@gmx.de, johncai86@gmail.com,
jonathantanmy@google.com, karthik.188@gmail.com,
kristofferhaugsbakk@fastmail.com, me@ttaylorr.com,
newren@gmail.com, peff@peff.net, ps@pks.im,
Derrick Stolee <stolee@gmail.com>
Subject: Re: [PATCH v2 00/13] PATH WALK II: Add --path-walk option to 'git pack-objects'
Date: Fri, 02 May 2025 14:24:30 -0700 [thread overview]
Message-ID: <xmqqbjsau2nl.fsf@gitster.g> (raw)
In-Reply-To: <pull.1819.v2.git.1742829769.gitgitgadget@gmail.com> (Derrick Stolee via GitGitGadget's message of "Mon, 24 Mar 2025 15:22:36 +0000")
"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:
> This patch series does the following:
>
> 1. Add a new '--path-walk' option to 'git pack-objects' that uses the
> path-walk API instead of the revision API to collect objects for delta
> compression.
>
> 2. Add a new '--path-walk' option to 'git repack' to pass this option along
> to 'git pack-objects'.
>
> 3. Add a new 'pack.usePathWalk' config option to opt into this option
> implicitly, such as in 'git push'.
>
> 4. Optimize the '--path-walk' option using threading so it better competes
> with the existing multi-threaded delta compression mechanism.
>
> 5. Update the path-walk API with a new 'edge_aggressive' option that pairs
> close to the --edge-aggressive option in the revision API. This is
> useful when creating thin packs inside shallow clones.
>
> This feature works by using the path-walk API to emit groups of objects that
> appear at the same path. These groups are tracked so they can be tested for
> delta compression with each other, and then after those groups are tested a
> second pass using the name-hash attempts to find better (or first time)
> deltas across path boundaries. This second pass is much faster than a fresh
> pass since the existing deltas are used as a limit for the size of
> potentially new deltas, short-circuiting the checks when the delta size
> exceeds the current-best.
> ...
> This feature was shipped with similar features in microsoft/git as of
> v2.47.0.vfs.0.3 [4]. This was used in CI machines for an internal monorepo
> that had significant repository growth due to constructing a batch of
> beachball [5] CHANGELOG.[md|json] files and pushing them to a release
> branch. These pushes were frequently 70-200 MB due to poor delta
> compression. Using the 'pack.usePathWalk=true' config, these pushes dropped
> in size by 100x while improving performance. Since these CI machines were
> working with a shallow clone, the 'edge_aggressive' changes were required to
> enable the path-walk option.
>
> [4] https://github.com/microsoft/git/releases/tag/v2.47.0.vfs.0.3
>
> [5] https://github.com/microsoft/beachball
>
>
> Updates in v2
> =============
>
> * Re-added a dropped comment when moving code in patch 1.
> * Updated documentation to include interaction with --use-bitmap-index.
> * An UNUSED parameter is now used, reducing the use of global variables
> slightly.
The iteration saw no comments from anybody, so I (naturally) forgot
about it for quite a long time. Let me mark it for 'next'.
Thanks.
next prev parent reply other threads:[~2025-05-02 21:24 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-10 1:50 [PATCH 00/13] PATH WALK II: Add --path-walk option to 'git pack-objects' Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 01/13] pack-objects: extract should_attempt_deltas() Derrick Stolee via GitGitGadget
2025-03-12 21:01 ` Taylor Blau
2025-03-20 19:48 ` Derrick Stolee
2025-03-10 1:50 ` [PATCH 02/13] pack-objects: add --path-walk option Derrick Stolee via GitGitGadget
2025-03-12 21:14 ` Taylor Blau
2025-03-20 19:46 ` Derrick Stolee
2025-03-10 1:50 ` [PATCH 03/13] pack-objects: update usage to match docs Derrick Stolee via GitGitGadget
2025-03-12 21:14 ` Taylor Blau
2025-03-10 1:50 ` [PATCH 04/13] p5313: add performance tests for --path-walk Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 05/13] pack-objects: introduce GIT_TEST_PACK_PATH_WALK Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 06/13] t5538: add tests to confirm deltas in shallow pushes Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 07/13] repack: add --path-walk option Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 08/13] pack-objects: enable --path-walk via config Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 09/13] scalar: enable path-walk during push " Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 10/13] pack-objects: refactor path-walk delta phase Derrick Stolee via GitGitGadget
2025-03-12 21:21 ` Taylor Blau
2025-03-20 19:57 ` Derrick Stolee
2025-03-10 1:50 ` [PATCH 11/13] pack-objects: thread the path-based compression Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 12/13] path-walk: add new 'edge_aggressive' option Derrick Stolee via GitGitGadget
2025-03-10 1:50 ` [PATCH 13/13] pack-objects: allow --shallow and --path-walk Derrick Stolee via GitGitGadget
2025-03-10 17:28 ` [PATCH 00/13] PATH WALK II: Add --path-walk option to 'git pack-objects' Junio C Hamano
2025-03-12 20:47 ` Taylor Blau
2025-03-20 20:18 ` Derrick Stolee
2025-03-24 15:22 ` [PATCH v2 " Derrick Stolee via GitGitGadget
2025-03-24 15:22 ` [PATCH v2 01/13] pack-objects: extract should_attempt_deltas() Derrick Stolee via GitGitGadget
2025-05-02 22:48 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 02/13] pack-objects: add --path-walk option Derrick Stolee via GitGitGadget
2025-05-02 23:21 ` Taylor Blau
2025-05-06 19:39 ` Derrick Stolee
2025-05-16 15:27 ` Derrick Stolee
2025-03-24 15:22 ` [PATCH v2 03/13] pack-objects: update usage to match docs Derrick Stolee via GitGitGadget
2025-03-24 15:22 ` [PATCH v2 04/13] p5313: add performance tests for --path-walk Derrick Stolee via GitGitGadget
2025-05-02 23:25 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 05/13] pack-objects: introduce GIT_TEST_PACK_PATH_WALK Derrick Stolee via GitGitGadget
2025-05-02 23:31 ` Taylor Blau
2025-05-06 19:43 ` Derrick Stolee
2025-03-24 15:22 ` [PATCH v2 06/13] t5538: add tests to confirm deltas in shallow pushes Derrick Stolee via GitGitGadget
2025-05-02 23:34 ` Taylor Blau
2025-05-16 15:32 ` Derrick Stolee
2025-03-24 15:22 ` [PATCH v2 07/13] repack: add --path-walk option Derrick Stolee via GitGitGadget
2025-05-02 23:38 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 08/13] pack-objects: enable --path-walk via config Derrick Stolee via GitGitGadget
2025-05-02 23:42 ` Taylor Blau
2025-05-06 19:46 ` Derrick Stolee
2025-05-16 15:41 ` Derrick Stolee
2025-03-24 15:22 ` [PATCH v2 09/13] scalar: enable path-walk during push " Derrick Stolee via GitGitGadget
2025-05-07 0:58 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 10/13] pack-objects: refactor path-walk delta phase Derrick Stolee via GitGitGadget
2025-05-07 1:14 ` Taylor Blau
2025-05-16 16:27 ` Derrick Stolee
2025-05-29 0:17 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 11/13] pack-objects: thread the path-based compression Derrick Stolee via GitGitGadget
2025-05-07 1:33 ` Taylor Blau
2025-03-24 15:22 ` [PATCH v2 12/13] path-walk: add new 'edge_aggressive' option Derrick Stolee via GitGitGadget
2025-03-24 15:22 ` [PATCH v2 13/13] pack-objects: allow --shallow and --path-walk Derrick Stolee via GitGitGadget
2025-05-02 21:24 ` Junio C Hamano [this message]
2025-05-02 22:45 ` [PATCH v2 00/13] PATH WALK II: Add --path-walk option to 'git pack-objects' Taylor Blau
2025-05-02 23:44 ` Taylor Blau
2025-05-07 1:35 ` Taylor Blau
2025-05-16 18:11 ` [PATCH v3 " Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 01/13] pack-objects: extract should_attempt_deltas() Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 02/13] pack-objects: add --path-walk option Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 03/13] pack-objects: update usage to match docs Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 04/13] p5313: add performance tests for --path-walk Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 05/13] pack-objects: introduce GIT_TEST_PACK_PATH_WALK Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 06/13] t5538: add tests to confirm deltas in shallow pushes Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 07/13] repack: add --path-walk option Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 08/13] pack-objects: enable --path-walk via config Derrick Stolee via GitGitGadget
2025-05-16 18:11 ` [PATCH v3 09/13] scalar: enable path-walk during push " Derrick Stolee via GitGitGadget
2025-05-16 18:12 ` [PATCH v3 10/13] pack-objects: refactor path-walk delta phase Derrick Stolee via GitGitGadget
2025-05-16 18:12 ` [PATCH v3 11/13] pack-objects: thread the path-based compression Derrick Stolee via GitGitGadget
2025-05-16 18:12 ` [PATCH v3 12/13] path-walk: add new 'edge_aggressive' option Derrick Stolee via GitGitGadget
2025-05-16 18:12 ` [PATCH v3 13/13] pack-objects: allow --shallow and --path-walk Derrick Stolee via GitGitGadget
2025-05-29 0:20 ` [PATCH v3 00/13] PATH WALK II: Add --path-walk option to 'git pack-objects' Taylor Blau
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqbjsau2nl.fsf@gitster.g \
--to=gitster@pobox.com \
--cc=christian.couder@gmail.com \
--cc=git@vger.kernel.org \
--cc=gitgitgadget@gmail.com \
--cc=johannes.schindelin@gmx.de \
--cc=johncai86@gmail.com \
--cc=jonathantanmy@google.com \
--cc=karthik.188@gmail.com \
--cc=kristofferhaugsbakk@fastmail.com \
--cc=me@ttaylorr.com \
--cc=newren@gmail.com \
--cc=peff@peff.net \
--cc=ps@pks.im \
--cc=stolee@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).