public inbox for git@vger.kernel.org 
 help / color / mirror / Atom feed
From: Junio C Hamano <gitster@pobox•com>
To: Christian Jaeger <chrjae@gmail•com>
Cc: Duy Nguyen <pclouds@gmail•com>,
	Philippe Vaucher <philippe.vaucher@gmail•com>,
	Jonathan Nieder <jrnieder@gmail•com>, David Kastrup <dak@gnu•org>,
	Git Mailing List <git@vger•kernel.org>
Subject: Re: git gc --aggressive led to about 40 times slower "git log --raw"
Date: Fri, 21 Feb 2014 09:36:14 -0800	[thread overview]
Message-ID: <xmqq4n3s5pwx.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <CAEjYwfU7un6wuA0Z-hSycROSWNdfQq1NawC7=+cNZeNu4-DpJg@mail.gmail.com> (Christian Jaeger's message of "Fri, 21 Feb 2014 00:32:48 +0000")

Christian Jaeger <chrjae@gmail•com> writes:

> Also, in "man git-gc" document --aggressive that it leads to slower
> *read* performance after the gc, I remember having red that option's
> docs when I ran it, and since it didn't mention that it makes reads
> slower, I didn't expect it to, and thus didn't remember this as the
> source of the problem when I noticed that things were slow.

Good point. We would at least need such a documentation update to
warn users.

> (But, I took from the discussion that increasing the gzip window size
> (?) would make things smaller anyway, so perhaps all that isn't even
> necessary?)

If you are talking about "--window" in "git repack --window=xxxx",
that is not related to gzip.  It is how many other "similar" objects
an object will be tried to delta against to find a smallest delta
that can represent it in the pack.  Such a better delta, if found,
can give you a packfile with a smaller depth that is as small as
another packfile created with a larger depth, which is an overall
win, and using a wider window is a way to achieve such a result.

  reply	other threads:[~2014-02-21 17:36 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-18  7:25 git gc --aggressive led to about 40 times slower "git log --raw" Christian Jaeger
2014-02-18  8:55 ` David Kastrup
2014-02-18  9:45   ` Duy Nguyen
2014-02-18 10:25     ` David Kastrup
2014-02-18 15:59       ` Jonathan Nieder
2014-02-18 20:59         ` Junio C Hamano
2014-02-18 22:46           ` Duy Nguyen
2014-02-19  0:10             ` Junio C Hamano
2014-02-19  0:33               ` Duy Nguyen
2014-02-19  8:38                 ` Philippe Vaucher
2014-02-19  9:01                   ` David Kastrup
2014-02-19 10:24                     ` Duy Nguyen
2014-02-19 10:14                   ` Duy Nguyen
2014-02-20  4:09                     ` Christian Jaeger
2014-02-20 16:48                     ` David Kastrup
2014-02-20 17:06                       ` David Kastrup
2014-02-20 18:07                         ` David Kastrup
2014-02-19 18:59                   ` Junio C Hamano
2014-02-20 23:35                     ` Duy Nguyen
2014-02-21  0:32                       ` Christian Jaeger
2014-02-21 17:36                         ` Junio C Hamano [this message]
2014-02-21  5:09                       ` Duy Nguyen
2014-02-21 17:47                       ` Junio C Hamano
2014-02-24  9:27                         ` Philippe Vaucher
2014-02-22  0:36           ` Duy Nguyen
2014-02-22  6:20             ` David Kastrup
2014-02-22  8:53               ` David Kastrup
2014-02-22  9:14                 ` Duy Nguyen
2014-02-22 13:00                   ` Duy Nguyen
2014-02-22  9:57               ` Andreas Schwab
2014-02-18 16:43     ` Christian Jaeger

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=xmqq4n3s5pwx.fsf@gitster.dls.corp.google.com \
    --to=gitster@pobox$(echo .)com \
    --cc=chrjae@gmail$(echo .)com \
    --cc=dak@gnu$(echo .)org \
    --cc=git@vger$(echo .)kernel.org \
    --cc=jrnieder@gmail$(echo .)com \
    --cc=pclouds@gmail$(echo .)com \
    --cc=philippe.vaucher@gmail$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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