From: Julian Phillips <julian@quantumfyre.co.uk>
To: Martin Fick <mfick@codeaurora.org>
Cc: <git@vger.kernel.org>
Subject: Re: Git is not scalable with too many refs/*
Date: Mon, 26 Sep 2011 19:37:10 +0100 [thread overview]
Message-ID: <88a00eadcbb4a7946dbe8d70dd0e933d@quantumfyre.co.uk> (raw)
In-Reply-To: <201109261207.52736.mfick@codeaurora.org>
On Mon, 26 Sep 2011 12:07:52 -0600, Martin Fick wrote:
-- snip --
> Ahh, I think I have some more clues. So while this change
> does not speed things up for me normally, I found a case
> where it does! I set my .git/config to have
>
> [core]
> compression = 0
>
> and ran git-gc on my repo. Now, with a modern git with this
> optimization in it (1.7.6, 1.7.7.rc0...), 'git branch' is
> almost instantaneous (.05s)! But, if I revert c774aa it
> takes > ~15s.
I don't understand this. I don't see why core.compression should have
anything to do with refs ...
> So, it appears that this optimization is foiled by
> compression? In the case when this optimization helps, it
> save about 15s, when it hurts (with compression), it seems
> to cost > 3mins. I am not sure this optimization is worth
> it? Would there be someway for it to adjust to the repo
> conditions?
Well, in the case I tried it was 1.2s vs 40s. It would seem that you
have managed to find some corner case. It doesn't seem right to punish
everyone who has large numbers of refs by making their commands take
orders of magnitude longer to save one person 3m. Much better to find,
understand and fix the actual cause.
I really can't see what effect core.compression can have on loading the
ref_list. Certainly the sort doesn't load anything from the object
database. It would be really good to profile and find out what is
taking all the time - I am assuming that the CPU is at 100% for the 3+
minutes?
Random thought. What happens to the with compression case if you leave
the commit in, but add a sleep(15) to the end of sort_refs_list?
--
Julian
next prev parent reply other threads:[~2011-09-26 18:37 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-09 3:44 Git is not scalable with too many refs/* NAKAMURA Takumi
2011-06-09 6:50 ` Sverre Rabbelier
2011-06-09 15:23 ` Shawn Pearce
2011-06-09 15:52 ` A Large Angry SCM
2011-06-09 15:56 ` Shawn Pearce
2011-06-09 16:26 ` Jeff King
2011-06-10 3:59 ` NAKAMURA Takumi
2011-06-13 22:27 ` Jeff King
2011-06-14 0:17 ` Andreas Ericsson
2011-06-14 0:30 ` Jeff King
2011-06-14 4:41 ` Junio C Hamano
2011-06-14 7:26 ` Sverre Rabbelier
2011-06-14 10:02 ` Johan Herland
2011-06-14 10:34 ` Sverre Rabbelier
2011-06-14 17:02 ` Jeff King
2011-06-14 19:20 ` Shawn Pearce
2011-06-14 19:47 ` Jeff King
2011-06-14 20:12 ` Shawn Pearce
2011-09-08 19:53 ` Martin Fick
2011-09-09 0:52 ` Martin Fick
2011-09-09 1:05 ` Thomas Rast
2011-09-09 1:13 ` Thomas Rast
2011-09-09 15:59 ` Jens Lehmann
2011-09-25 20:43 ` Martin Fick
2011-09-26 12:41 ` Christian Couder
2011-09-26 17:47 ` Martin Fick
2011-09-26 18:56 ` Christian Couder
2011-09-30 16:41 ` Martin Fick
2011-09-30 19:26 ` Martin Fick
2011-09-30 21:02 ` Martin Fick
2011-09-30 22:06 ` Martin Fick
2011-10-01 20:41 ` Junio C Hamano
2011-10-02 5:19 ` Michael Haggerty
2011-10-03 0:46 ` Martin Fick
2011-10-04 8:08 ` Michael Haggerty
2011-10-03 18:12 ` Martin Fick
2011-10-03 19:42 ` Junio C Hamano
2011-10-04 8:16 ` Michael Haggerty
2011-10-08 20:59 ` Martin Fick
2011-10-09 5:43 ` Michael Haggerty
2011-09-28 19:38 ` Martin Fick
2011-09-28 22:10 ` Martin Fick
2011-09-29 0:54 ` Julian Phillips
2011-09-29 1:37 ` Martin Fick
2011-09-29 2:19 ` Julian Phillips
2011-09-29 16:38 ` Martin Fick
2011-09-29 18:26 ` Julian Phillips
2011-09-29 18:27 ` René Scharfe
2011-09-29 19:10 ` Junio C Hamano
2011-09-29 4:18 ` [PATCH] refs: Use binary search to lookup refs faster Julian Phillips
2011-09-29 21:57 ` Junio C Hamano
2011-09-29 22:04 ` [PATCH v2] " Julian Phillips
2011-09-29 22:06 ` [PATCH] " Junio C Hamano
2011-09-29 22:11 ` [PATCH v3] " Julian Phillips
2011-09-29 23:48 ` Junio C Hamano
2011-09-30 15:30 ` Michael Haggerty
2011-09-30 16:38 ` Junio C Hamano
2011-09-30 17:56 ` [PATCH] refs: Remove duplicates after sorting with qsort Julian Phillips
2011-10-02 5:15 ` [PATCH v3] refs: Use binary search to lookup refs faster Michael Haggerty
2011-10-02 5:45 ` Junio C Hamano
2011-10-04 20:58 ` Junio C Hamano
2011-09-30 1:13 ` Martin Fick
2011-09-30 3:44 ` Junio C Hamano
2011-09-30 8:04 ` Julian Phillips
2011-09-30 15:45 ` Martin Fick
2011-09-29 20:44 ` Git is not scalable with too many refs/* Martin Fick
2011-09-29 19:10 ` Julian Phillips
2011-09-29 20:11 ` Martin Fick
2011-09-30 9:12 ` René Scharfe
2011-09-30 16:09 ` Martin Fick
2011-09-30 16:52 ` Junio C Hamano
2011-09-30 18:17 ` René Scharfe
2011-10-01 15:28 ` René Scharfe
2011-10-01 15:38 ` [PATCH 1/8] checkout: check for "Previous HEAD" notice in t2020 René Scharfe
2011-10-01 19:02 ` Sverre Rabbelier
2011-10-01 15:43 ` [PATCH 2/8] revision: factor out add_pending_sha1 René Scharfe
2011-10-01 15:51 ` [PATCH 3/8] checkout: use add_pending_{object,sha1} in orphan check René Scharfe
2011-10-01 15:56 ` [PATCH 4/8] revision: add leak_pending flag René Scharfe
2011-10-01 16:01 ` [PATCH 5/8] bisect: use " René Scharfe
2011-10-01 16:02 ` [PATCH 6/8] bundle: " René Scharfe
2011-10-01 16:09 ` [PATCH 7/8] checkout: " René Scharfe
2011-10-01 16:16 ` [PATCH 8/8] commit: factor out clear_commit_marks_for_object_array René Scharfe
2011-09-26 15:15 ` Git is not scalable with too many refs/* Martin Fick
2011-09-26 15:21 ` Sverre Rabbelier
2011-09-26 15:48 ` Martin Fick
2011-09-26 15:56 ` Sverre Rabbelier
2011-09-26 16:38 ` Martin Fick
2011-09-26 16:49 ` Julian Phillips
2011-09-26 18:07 ` Martin Fick
2011-09-26 18:37 ` Julian Phillips [this message]
2011-09-26 20:01 ` Martin Fick
2011-09-26 20:07 ` Junio C Hamano
2011-09-26 20:28 ` Julian Phillips
2011-09-26 21:39 ` Martin Fick
2011-09-26 21:52 ` Martin Fick
2011-09-26 23:26 ` Julian Phillips
2011-09-26 23:37 ` David Michael Barr
2011-09-27 1:01 ` [PATCH] refs.c: Fix slowness with numerous loose refs David Barr
2011-09-27 2:04 ` David Michael Barr
2011-09-26 23:38 ` Git is not scalable with too many refs/* Junio C Hamano
2011-09-27 0:00 ` [PATCH] Don't sort ref_list too early Julian Phillips
2011-10-02 4:58 ` Michael Haggerty
2011-09-27 0:12 ` Git is not scalable with too many refs/* Martin Fick
2011-09-27 0:22 ` Julian Phillips
2011-09-27 2:34 ` Martin Fick
2011-09-27 7:59 ` Julian Phillips
2011-09-27 8:20 ` Sverre Rabbelier
2011-09-27 9:01 ` Julian Phillips
2011-09-27 10:01 ` Sverre Rabbelier
2011-09-27 10:25 ` Nguyen Thai Ngoc Duy
2011-09-27 11:07 ` Michael Haggerty
2011-09-27 12:10 ` Julian Phillips
2011-09-26 22:30 ` Julian Phillips
2011-09-26 15:32 ` Michael Haggerty
2011-09-26 15:42 ` Martin Fick
2011-09-26 16:25 ` Thomas Rast
2011-09-09 13:50 ` Michael Haggerty
2011-09-09 15:51 ` Michael Haggerty
2011-09-09 16:03 ` Jens Lehmann
2011-06-10 7:41 ` Andreas Ericsson
2011-06-10 19:41 ` Shawn Pearce
2011-06-10 20:12 ` Jakub Narebski
2011-06-10 20:35 ` Jeff King
2011-06-13 7:08 ` Andreas Ericsson
2011-06-09 11:18 ` Jakub Narebski
2011-06-09 15:42 ` Stephen Bash
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=88a00eadcbb4a7946dbe8d70dd0e933d@quantumfyre.co.uk \
--to=julian@quantumfyre.co.uk \
--cc=git@vger.kernel.org \
--cc=mfick@codeaurora.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.