From: Derrick Stolee <stolee@gmail.com>
Date: Fri, 13 Oct 2017 14:30:48 GMT
Subject: Re: git-clone causes out of memory
Message-ID: <c4b88c7e-7be3-6acb-71f9-fb0185dc0b7d@gmail.com>
In-Reply-To: <20171013142646.evapso5uxzvh2r2p@sigill.intra.peff.net>

On 10/13/2017 10:26 AM, Jeff King wrote:
> On Fri, Oct 13, 2017 at 10:25:10AM -0400, Derrick Stolee wrote:
>
>> This does appear to be the problem. The missing DIFF_OPT_HAS_CHANGES is
>> causing diff_can_quit_early() to return false. Due to the corner-case of the
>> bug it seems it will not be a huge performance improvement in most cases.
>> Still worth fixing and I'm looking at your suggestions to try and learn this
>> area better.
> Yeah, I just timed some pathspec limits on linux.git, and it makes at
> best a fraction of a percent improvement (but any improvement is well
> within run-to-run noise). Which is not surprising.
>
> I agree it's worth fixing, though.
>
> -Peff

I just ran a first-level folder history in the Windows repository and 
`git rev-list HEAD -- windows >/dev/null` went from 0.43s to 0.04s. So, 
a good percentage improvement but even on this enormous repo the bug 
doesn't present an issue to human users.

Thanks,
-Stolee