From: Clement Moyroud <clement.moyroud@gmail.com>
To: bturner@atlassian.com
Cc: git@vger.kernel.org
Subject: Re: Git blame performance on files with a lot of history
Date: Mon, 17 Dec 2018 12:43:31 -0800 [thread overview]
Message-ID: <CABXAcUyiJOcZwjSyvCKJC0vKDRbSP21sY_Fa7-WfmQHsczYbzQ@mail.gmail.com> (raw)
In-Reply-To: <CAGyf7-EZaiVBnoBfRJXAK7KdaXzPaDFVocUrB8LQNU_Hi16u7g@mail.gmail.com>
did hOn Fri, Dec 14, 2018 at 11:10 AM Bryan Turner
<bturner@atlassian.com> wrote:
>
> After you converted the repository from CVS to Git, did you run a manual repack?
>
> The process of converting a repository from another SCM often results
> in poor delta chain selections which result in a repository that's
> unnecessarily large on disk, and/or performs quite slowly.
>
Yep I did a repack, using 'git repack -A -d --pack-kept-objects'. On
NFS it'd be even
worse, because of all the small objects Git would have to go through.
> Something like `git repack -Adf --depth=50 --window=200` discards the
> existing delta chains and chooses new ones, and may result in
> significantly improved performance. A smaller depth, like --depth=20,
> might result in even more performance improvement, but may also make
> the repository larger on disk; you'll need to find the balance that
> works for you.
>
I re-ran with 'git repack -Adf --depth=20 --window=200' and that did
help quite a bit:
> time git blame master -- important/file.C > /tmp/foo
Blaming lines: 100% (33179/33179), done.
git blame master -- important/file.C > /tmp/foo 50.70s user 0.55s
system 99% cpu 51.298 total
That's roughly a 3x improvement, great. I just need another 10x one
and we'll be in business :) Based on
experiments with the Bloom filter, maybe that'll help enough to get
our users on board.
Cheers,
Clément
next prev parent reply other threads:[~2018-12-17 20:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-14 18:29 Git blame performance on files with a lot of history Clement Moyroud
2018-12-14 19:10 ` Bryan Turner
2018-12-17 20:43 ` Clement Moyroud [this message]
2018-12-14 21:31 ` Derrick Stolee
2018-12-17 20:59 ` Clement Moyroud
2018-12-14 22:48 ` Ævar Arnfjörð Bjarmason
2018-12-17 20:30 ` Clement Moyroud
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