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From: Junio C Hamano <gitster@pobox•com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail•com>
Cc: Duy Nguyen <pclouds@gmail•com>,
	Stephen Morton <stephen.c.morton@gmail•com>,
	Git Mailing List <git@vger•kernel.org>
Subject: Re: Git Scaling: What factors most affect Git performance for a large repo?
Date: Mon, 02 Mar 2015 12:15:39 -0800	[thread overview]
Message-ID: <xmqqsidn9mvo.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <CACBZZX7O77zfn75vJXsSyR58UjC_bfTu-DWwJC8n2fhemVBn2w@mail.gmail.com> ("Ævar Arnfjörð Bjarmason"'s message of "Mon, 2 Mar 2015 20:36:43 +0100")

Ævar Arnfjörð Bjarmason <avarab@gmail•com> writes:

> On Fri, Feb 20, 2015 at 10:04 PM, Junio C Hamano <gitster@pobox•com> wrote:
>> Ævar Arnfjörð Bjarmason <avarab@gmail•com> writes:
>>
>>> I actually ran this a few times while testing it, so this is a before
>>> and after on a hot cache of linux.git with 406 tags v.s. ~140k. I ran
>>> the gc + repack + bitmaps for both repos noted in an earlier reply of
>>> mine, and took the fastest run out of 3:
>>>
>>>     $ time (git log master -100 >/dev/null)
>>>     Before: real    0m0.021s
>>>     After: real    0m2.929s
>>
>> Do you force --decorate with some config?  Or do you see similar
>> performance difference with "git rev-parse master", too?
>
> Yes, I had log.decorate=short set in my config. With --no-decorate:
>
>     $ time (git log --no-decorate -100 >/dev/null)
>     # Before: real    0m0.010s
>     # After: real    0m0.065s

There you have the answer to your earlier question, then, which was:

>> tl;dr: After some more testing it turns out the performance issues we
>> have are almost entirely due to the number of refs. Some of these I
>> knew about and were obvious (e..g. git pull), but some aren't so
>> obvious (why does "git log" without "--all" slow down as a function of
>> the overall number of refs?).

  reply	other threads:[~2015-03-02 20:16 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-19 21:26 Git Scaling: What factors most affect Git performance for a large repo? Stephen Morton
2015-02-19 22:21 ` Stefan Beller
2015-02-19 23:06   ` Stephen Morton
2015-02-19 23:15     ` Stefan Beller
2015-02-19 23:29 ` Ævar Arnfjörð Bjarmason
2015-02-20  0:04   ` Duy Nguyen
2015-02-20 12:09     ` Ævar Arnfjörð Bjarmason
2015-02-20 12:11       ` Ævar Arnfjörð Bjarmason
2015-02-20 14:25       ` Ævar Arnfjörð Bjarmason
2015-02-20 21:04         ` Junio C Hamano
2015-03-02 19:36           ` Ævar Arnfjörð Bjarmason
2015-03-02 20:15             ` Junio C Hamano [this message]
2015-02-20 22:02         ` Sebastian Schuberth
2015-02-24 12:44         ` Michael Haggerty
2015-03-02 19:42           ` Ævar Arnfjörð Bjarmason
2015-02-21  3:51       ` Duy Nguyen
2015-02-19 23:38 ` Duy Nguyen
2015-02-20  0:42   ` David Turner
2015-02-20 20:59     ` Junio C Hamano
2015-02-23 20:23       ` David Turner
2015-02-21  4:01     ` Duy Nguyen
2015-02-25 12:02       ` Duy Nguyen
2015-02-20  0:03 ` brian m. carlson
2015-02-20 16:06   ` Stephen Morton
2015-02-20 16:38     ` Matthieu Moy
2015-02-20 17:16     ` brian m. carlson
2015-02-20 22:08   ` Sebastian Schuberth
2015-02-20 22:58     ` brian m. carlson
  -- strict thread matches above, loose matches on Subject: below --
2015-02-20  6:57 Martin Fick
2015-02-20 18:29 ` David Turner
2015-02-20 20:37   ` Martin Fick
2015-02-21  0:41     ` David Turner
2015-02-20 19:27 ` Randall S. Becker

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