Re: Git is not scalable with too many refs/*

From: Martin Fick <mfick@codeaurora.org>
Date: Sep 26, 2011, 15:48 UTC
Message-ID: <201109260948.25312.mfick@codeaurora.org>
In-Reply-To: <CAGdFq_iuY0-PBDOmtz1pRvh6J9EDRiRJHsWkTN_cHjGU20PYTQ@mail.gmail.com>

On Monday, September 26, 2011 09:21:30 am Sverre Rabbelier wrote:

> Heya,
> 
> On Mon, Sep 26, 2011 at 17:15, Martin Fick

<mfick@codeaurora.org> wrote:

Show 10 quoted lines

> > If this change does not actually speed things up,
> > should it be reverted?  Or was there a bug in the
> > change that makes it not do what it was supposed to
> > do?
> 
> It probably looks at the refs in refs/changes while it
> shouldn't, hence worsening your performance compared to
> not looking at those refs. I assume that it does improve
> your situation if you have all those refs under say
> refs/heads.

Hmm, I was thinking that too, and I just did a test.

Instead of storing the changes under refs/changes, I fetched them under refs/heads/changes and then ran git 1.7.6 and it took about 3 mins. Then, I ran the 1.7.7.rc0.73 with c774aab98ce6c5ef7aaacbef38da0a501eb671d4 reverted and it only took 13s! So, if this indeed tests what you were suggesting, I think it shows that even in the intended case this change slowed things down?

-Martin

-- 
Employee of Qualcomm Innovation Center, Inc. which is a 
member of Code Aurora Forum