From: Jeff King <peff@peff.net>
To: Duy Nguyen <pclouds@gmail.com>
Cc: Elijah Newren <newren@gmail.com>, Git Mailing List <git@vger.kernel.org>
Subject: Re: 2.18.0 Regression: packing performance and effectiveness
Date: Thu, 19 Jul 2018 01:49:54 -0400 [thread overview]
Message-ID: <20180719054953.GA24268@sigill.intra.peff.net> (raw)
In-Reply-To: <CACsJy8Cc=h3ptDaW=oUGXqRZAvNU8-pUCe1cVFpRd0t8O1a0Gw@mail.gmail.com>
On Thu, Jul 19, 2018 at 07:41:03AM +0200, Duy Nguyen wrote:
> On Thu, Jul 19, 2018 at 12:51 AM Elijah Newren <newren@gmail.com> wrote:
> >
> > I had a user report some poor behavior of 'git gc --aggressive' on a
> > certain repo (which I sadly cannot share). Turns out that on this
> > repo, this operation takes about 60% longer and produces a pack
> > roughly twice the expected size.
>
> The intention was to make life better for weaker machines but
> definitely should not slow down beefier ones, so yes this is
> definitely a regression.
>
> Is it possible to share "verify-pack -v <pack file>" output of the
> pack produced by 2.17.0 and 2.18.0? The only sensitive info there is
> sha-1, which you can replace with just "SHA-1" if you want. I'm more
> interested in delta sizes and distribution.
Try this:
-- >8 --
#!/bin/sh
rm -rf repo
git init repo
cd repo
dd if=/dev/urandom of=one.rand bs=1M count=2
dd if=/dev/urandom of=two.rand bs=1M count=2
dd if=/dev/urandom of=big.rand bs=1M count=20
cat one.rand big.rand >file
git add file
git commit -m one
cat two.rand big.rand >file
git add file
git commit -m two
git repack -ad
git cat-file --batch-all-objects --batch-check='%(objectname) %(deltabase)'
-- 8< --
Using git 2.17 for the repack results in a single delta (which should be
about 2MB, because it will say "delete one.rand and add two.rand" or
vice versa).
Using git 2.18, I get no delta at all.
-Peff
next prev parent reply other threads:[~2018-07-19 5:49 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 22:51 2.18.0 Regression: packing performance and effectiveness Elijah Newren
2018-07-18 22:51 ` [RFC PATCH] fix-v1: revert "pack-objects: shrink delta_size field in struct object_entry" Elijah Newren
2018-07-18 22:51 ` [RFC PATCH] fix-v2: make OE_DELTA_SIZE_BITS a bit bigger Elijah Newren
2018-07-19 5:41 ` 2.18.0 Regression: packing performance and effectiveness Duy Nguyen
2018-07-19 5:49 ` Jeff King [this message]
2018-07-19 15:27 ` Elijah Newren
2018-07-19 15:43 ` Duy Nguyen
2018-07-19 5:44 ` Jeff King
2018-07-19 5:57 ` Duy Nguyen
2018-07-19 15:16 ` Duy Nguyen
2018-07-19 16:42 ` Elijah Newren
2018-07-19 17:23 ` Jeff King
2018-07-19 17:31 ` Duy Nguyen
2018-07-19 18:24 ` Duy Nguyen
2018-07-19 19:17 ` Jeff King
2018-07-19 23:11 ` Elijah Newren
2018-07-20 5:28 ` Jeff King
2018-07-20 5:30 ` Jeff King
2018-07-20 5:47 ` Duy Nguyen
2018-07-20 17:21 ` Elijah Newren
2018-07-19 17:04 ` Jeff King
2018-07-19 19:25 ` Junio C Hamano
2018-07-19 19:27 ` Junio C Hamano
2018-07-20 15:39 ` [PATCH] pack-objects: fix performance issues on packing large deltas Nguyễn Thái Ngọc Duy
2018-07-20 17:40 ` Jeff King
2018-07-21 4:23 ` Duy Nguyen
2018-07-23 21:37 ` Jeff King
2018-07-20 17:43 ` Elijah Newren
2018-07-20 23:52 ` Elijah Newren
2018-07-21 4:07 ` Duy Nguyen
2018-07-21 7:08 ` Duy Nguyen
2018-07-21 4:47 ` Duy Nguyen
2018-07-21 6:56 ` Elijah Newren
2018-07-21 7:14 ` Duy Nguyen
2018-07-22 6:22 ` Elijah Newren
2018-07-22 6:49 ` Duy Nguyen
2018-07-23 12:34 ` Elijah Newren
2018-07-23 15:50 ` Duy Nguyen
2018-07-22 8:04 ` [PATCH v2] " Nguyễn Thái Ngọc Duy
2018-07-23 18:04 ` Junio C Hamano
2018-07-23 18:38 ` Duy Nguyen
2018-07-23 18:49 ` Duy Nguyen
2018-07-23 21:30 ` Jeff King
2018-07-26 8:12 ` Johannes Sixt
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=20180719054953.GA24268@sigill.intra.peff.net \
--to=peff@peff.net \
--cc=git@vger.kernel.org \
--cc=newren@gmail.com \
--cc=pclouds@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).