git.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Elijah Newren <newren@gmail.com>
To: Ben Peart <Ben.Peart@microsoft.com>
Cc: "git@vger.kernel.org" <git@vger.kernel.org>,
	"peff@peff.net" <peff@peff.net>,
	"gitster@pobox.com" <gitster@pobox.com>,
	"pclouds@gmail.com" <pclouds@gmail.com>,
	"vmiklos@frugalware.org" <vmiklos@frugalware.org>,
	Kevin Willford <kewillf@microsoft.com>,
	"Johannes.Schindelin@gmx.de" <Johannes.Schindelin@gmx.de>
Subject: Re: [PATCH v1 0/2] add additional config settings for merge
Date: Fri, 20 Apr 2018 10:34:48 -0700	[thread overview]
Message-ID: <CABPp-BEwwn+NwOEtWOKOdUKxoXfq6YwWeoH6OwkPjSwVtTm5=Q@mail.gmail.com> (raw)
In-Reply-To: <20180420133632.17580-1-benpeart@microsoft.com>

On Fri, Apr 20, 2018 at 6:36 AM, Ben Peart <Ben.Peart@microsoft.com> wrote:
> This enables the user to set a couple of additional options for merge.
>
> 1. merge.aggressive - this is to try to resolve a few more trivial
>    merge cases.  It is documented in read-tree and is not something you
>    can pass into merge itself.
>
> 2. merge.renames - this is to save git from having to go through the entire
>    3 trees to see if there were any renames that happened.
>
> For the work item repro that I have been using this drops the merge time
> from ~1 hour to ~5 minutes and the unmerged entries goes down from
> ~40,000 to 1.

Ooh, this is *very* interesting.  Is there any chance I could also get
you to test performing the same merge with the version of git at
https://github.com/newren/git/tree/big-repo-small-cherry-pick and
report on your timings?

The 'big-repo-small-cherry-pick' name could be improved, but that
branch has a number of performance fixes for really poor rename
detection performance during merges.  From your description, I'm
pretty sure it'll apply to your case.  For my specific testcase,  I
got a speedup factor of 30.  Someone else on the list saw a factor of
24[1].  Results are highly dependent on the specific repo, but it's
certainly possible that it gets much of your factor of 12 speedup that
you saw with these new config settings you added.

However, what makes this case even more interesting to me is that my
branch may not be quite as effective as your workarounds.  There are
other other performance issues in merge that I am aware of, but for
which I haven't had the time to write the patches yet (I've been
waiting for the directory rename detection stuff to land and settle
down before working more on the performance aspects).  I do not know
how big a factor those other performance issues are, but your
workarounds (namely the aggressive setting) may get around some of
those other issues as well, so I'm very interested to see how my
current branch compares to the speedups you got with these settings.

Thanks,
Elijah


[1] https://public-inbox.org/git/alpine.DEB.2.00.1711211303290.20686@ds9.cixit.se/

  parent reply	other threads:[~2018-04-20 17:34 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-20 13:36 Ben Peart
2018-04-20 13:36 ` [PATCH v1 1/2] merge: Add merge.renames config setting Ben Peart
2018-04-20 17:02   ` Elijah Newren
2018-04-20 17:26     ` Elijah Newren
2018-04-23 12:57       ` Ben Peart
2018-04-20 17:59     ` Ben Peart
2018-04-20 18:34       ` Elijah Newren
2018-04-21  4:23         ` Junio C Hamano
2018-04-23 16:00           ` Ben Peart
2018-04-23 23:23             ` Junio C Hamano
2018-04-24 11:58               ` Johannes Schindelin
2018-04-24 17:47                 ` Elijah Newren
2018-04-25  8:20                   ` Johannes Schindelin
2018-04-22 12:07         ` Eckhard Maaß
2018-04-23 13:15           ` Ben Peart
2018-04-23 21:32             ` Eckhard Maaß
2018-04-24 16:53               ` Ben Peart
2018-04-23 13:22         ` Ben Peart
2018-04-20 13:36 ` [PATCH v1 2/2] merge: Add merge.aggressive " Ben Peart
2018-04-20 17:22   ` Elijah Newren
2018-04-24 16:45     ` Ben Peart
2018-04-24 17:36       ` Elijah Newren
2018-04-24 23:57       ` Junio C Hamano
2018-04-25 14:47         ` Ben Peart
2018-04-20 17:34 ` Elijah Newren [this message]
2018-04-20 18:19   ` [PATCH v1 0/2] add additional config settings for merge Ben Peart
2018-04-24 17:11 ` [PATCH v2 " Ben Peart
2018-04-24 17:11   ` [PATCH v2 1/2] merge: Add merge.renames config setting Ben Peart
2018-04-24 18:11     ` Elijah Newren
2018-04-24 18:59     ` Elijah Newren
2018-04-24 20:31       ` Ben Peart
2018-04-25 16:01         ` Elijah Newren
2018-04-24 17:11   ` [PATCH v2 2/2] merge: Add merge.aggressive " Ben Peart
2018-04-25  0:13   ` [PATCH v2 0/2] add additional config settings for merge Junio C Hamano
2018-04-25 15:22     ` Ben Peart
2018-04-26  1:48       ` Junio C Hamano
2018-04-26 20:52 ` [PATCH v3 0/3] add merge.renames config setting Ben Peart
2018-04-26 20:52   ` [PATCH v3 1/3] merge: update documentation for {merge,diff}.renameLimit Ben Peart
2018-04-26 23:11     ` Elijah Newren
2018-04-26 23:23       ` Jonathan Tan
2018-04-26 20:52   ` [PATCH v3 2/3] merge: Add merge.renames config setting Ben Peart
2018-04-26 22:52     ` Elijah Newren
2018-04-27  0:54       ` Ben Peart
2018-04-27  2:23         ` Junio C Hamano
2018-04-27  3:28           ` Elijah Newren
2018-04-27  7:23             ` Johannes Schindelin
2018-04-27 14:32               ` Elijah Newren
2018-04-27 18:37           ` Eckhard Maaß
2018-04-27 20:23             ` Elijah Newren
2018-04-30  8:03               ` Eckhard Maaß
2018-04-30 16:54                 ` Elijah Newren
2018-04-27  4:17         ` Elijah Newren
2018-04-27 18:19         ` Elijah Newren
2018-04-30 13:11           ` Ben Peart
2018-04-30 16:12             ` Re: Elijah Newren
2018-05-02 14:33               ` Re: Ben Peart
2018-04-26 20:52   ` [PATCH v3 3/3] merge: pass aggressive when rename detection is turned off Ben Peart
2018-04-26 23:00     ` Elijah Newren
2018-04-26 22:08   ` [PATCH v3 0/3] add merge.renames config setting Elijah Newren
2018-05-02 16:01 ` [PATCH v4 0/3] add additional config settings for merge Ben Peart
2018-05-02 16:01   ` [PATCH v4 1/3] merge: update documentation for {merge,diff}.renameLimit Ben Peart
2018-05-02 16:01   ` [PATCH v4 2/3] merge: Add merge.renames config setting Ben Peart
2018-05-04  3:07     ` Junio C Hamano
2018-05-02 16:01   ` [PATCH v4 3/3] merge: pass aggressive when rename detection is turned off Ben Peart
2018-05-02 17:20   ` [PATCH v4 0/3] add additional config settings for merge Elijah Newren

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='CABPp-BEwwn+NwOEtWOKOdUKxoXfq6YwWeoH6OwkPjSwVtTm5=Q@mail.gmail.com' \
    --to=newren@gmail.com \
    --cc=Ben.Peart@microsoft.com \
    --cc=Johannes.Schindelin@gmx.de \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=kewillf@microsoft.com \
    --cc=pclouds@gmail.com \
    --cc=peff@peff.net \
    --cc=vmiklos@frugalware.org \
    --subject='Re: [PATCH v1 0/2] add additional config settings for merge' \
    /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

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 NNTP newsgroup(s).