Re: speed of git reset -- file

[Jeff King <peff@peff.net>]

On Wed, Jun 01, 2011 at 06:05:02PM -0400, Joey Hess wrote:

> Jeff King wrote:
> > > My experience with semi-large trees[1] is that I have to remember to use
> > > "git status ." in a subdir; that "git commit -a" is of course slow when
> > > I need to use it; and that the index gets big and things that need to
> > > update it can become somewhat slow especially on slow disks, but that
> > 
> > Generally I find that the stats are very fast because everything is in
> > cache, and the disk doesn't come into it at all. Are you on an OS
> > besides Linux, or on a machine with low memory?
> 
> I have Linux and a gigabyte of ram and a not particularly good SSD.
> Here `git reset file` takes 30 seconds, `git status` 45 seconds.

OK, that's horrific. For me, the stat information for linux-2.6 all sits
in cache and it takes about 0.3 seconds to refresh the index. I have 8G
of ram and a nice SSD, though it doesn't actually hit the disk at all.

Is it really faulting the stat information from disk that takes so long?
Have you tried running "perf" on "git update-index --refresh"?

-Peff