Re: git checkout running very slowly (>12s)

From: Andreas Ericsson <ae@op5.se>
Date: Jun 15, 2011, 22:46 UTC
Message-ID: <4DF9363F.6080009@op5.se>
In-Reply-To: <loom.20110615T213016-856@post.gmane.org>

On 06/15/2011 09:30 PM, Andrew Cameron wrote:

Show 5 quoted lines

> Some git operations (notably checkouts) are taking a very long time to execute.
> Here is a shell session which illustrates the problem.
> 
> $ time git branch foo
> git branch foo  0.01s user 0.00s system 77% cpu 0.016 total

Creating a branch is just a matter of creating a new ref. In this case, you're doing it on the currently checked out ref. That's a constant-time operation that is always very quick.

> $ time git checkout foo
> Switched to branch 'foo'
> git checkout foo  11.73s user 0.18s system 99% cpu 11.937 total

If this sequence of commands is accurate, that's a bit weird. If you've got another branch checked out first and then switch it would be understandable, considering the size of the repository. We should probably still do a tree-by-tree comparison to see which files are changed though, but I thought that's already done to avoid superfluous work and allow worktree changes to carry over to other branches. What version of git are you using?

Show 12 quoted lines

> $ time git checkout master
> Switched to branch 'master'
> git checkout master  11.62s user 0.18s system 99% cpu 11.813 total
> $ git count-objects -v
> count: 953
> size: 527012
> in-pack: 153432
> packs: 7
> size-pack: 1986072
> prune-packable: 0
> garbage: 0
>

These figures are nowhere near as interesting as those from
  git ls-files | wc -l
after the checkout is completed.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

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