From: Patrick Steinhardt <ps@pks.im>
To: git@vger.kernel.org
Cc: Taylor Blau <me@ttaylorr.com>, Derrick Stolee <stolee@gmail.com>
Subject: [PATCH v2 0/2] fetch: speed up mirror-fetches with many refs
Date: Wed, 2 Feb 2022 13:51:43 +0100 [thread overview]
Message-ID: <cover.1643806143.git.ps@pks.im> (raw)
In-Reply-To: <cover.1643364888.git.ps@pks.im>
[-- Attachment #1: Type: text/plain, Size: 2458 bytes --]
Hi,
this is the second version of my patch series which aims to speed up
mirror-fetches in repos with huge amounts of refs. The only change
compared to v1 is a fixed up commit message: Taylor has pointed out to
me that commit dates retrieved from the commit-graph are not in fact the
corrected commit dates, which are stored separately.
Patrick
Patrick Steinhardt (2):
fetch-pack: use commit-graph when computing cutoff
fetch: skip computing output width when not printing anything
builtin/fetch.c | 8 ++++++--
fetch-pack.c | 28 ++++++++++++++++------------
2 files changed, 22 insertions(+), 14 deletions(-)
Range-diff against v1:
1: 31cf8f87a1 ! 1: 6fac914f0f fetch-pack: use commit-graph when computing cutoff
@@ Commit message
the cutoff date. This can be sped up by trying to look up commits via
the commit-graph first, which is a lot more efficient.
- One thing to keep in mind though is that the commit-graph corrects
- committer dates:
-
- * A commit with at least one parent has corrected committer date
- equal to the maximum of its commiter date and one more than the
- largest corrected committer date among its parents.
-
- As a result, it may be that the commit date we load via the commit graph
- is more recent than it would have been when loaded via the ODB, and as a
- result we may also choose a more recent cutoff point. But as the code
- documents, this is only a heuristic and it is okay if we determine a
- wrong cutoff date. The worst that can happen is that we report more
- commits as HAVEs to the server when using corrected dates.
-
- Loading commits via the commit-graph is typically much faster than
- loading commits via the object database. Benchmarks in a repository with
- about 2,1 million refs and an up-to-date commit-graph show a 20% speedup
- when mirror-fetching:
+ Benchmarks in a repository with about 2,1 million refs and an up-to-date
+ commit-graph show a 20% speedup when mirror-fetching:
Benchmark 1: git fetch --atomic +refs/*:refs/* (v2.35.0)
Time (mean ± σ): 75.264 s ± 1.115 s [User: 68.199 s, System: 10.094 s]
2: 5a3fd3232f = 2: 4b9bbcf795 fetch: skip computing output width when not printing anything
--
2.35.1
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2022-02-02 12:51 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-28 10:15 [PATCH 0/2] fetch: speed up mirror-fetches with many refs Patrick Steinhardt
2022-01-28 10:17 ` [PATCH 1/2] fetch-pack: use commit-graph when computing cutoff Patrick Steinhardt
2022-01-31 22:53 ` Taylor Blau
2022-02-02 12:46 ` Patrick Steinhardt
2022-01-28 10:19 ` [PATCH 2/2] fetch: skip computing output width when not printing anything Patrick Steinhardt
2022-02-02 12:51 ` Patrick Steinhardt [this message]
2022-02-02 12:51 ` [PATCH v2 1/2] fetch-pack: use commit-graph when computing cutoff Patrick Steinhardt
2022-02-09 18:01 ` Christian Couder
2022-02-10 11:43 ` Patrick Steinhardt
2022-02-02 12:51 ` [PATCH v2 2/2] fetch: skip computing output width when not printing anything Patrick Steinhardt
2022-02-09 18:10 ` Christian Couder
2022-02-10 12:23 ` Patrick Steinhardt
2022-02-10 12:28 ` [PATCH v3 0/2] fetch: speed up mirror-fetches with many refs Patrick Steinhardt
2022-02-10 12:28 ` [PATCH v3 1/2] fetch-pack: use commit-graph when computing cutoff Patrick Steinhardt
2022-02-10 12:28 ` [PATCH v3 2/2] fetch: skip computing output width when not printing anything Patrick Steinhardt
2022-02-10 18:04 ` [PATCH v3 0/2] fetch: speed up mirror-fetches with many refs Junio C Hamano
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
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cover.1643806143.git.ps@pks.im \
--to=ps@pks.im \
--cc=git@vger.kernel.org \
--cc=me@ttaylorr.com \
--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.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
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).