From: Jeff King <peff@peff.net>
Date: Mon, 20 Feb 2012 14:06:53 GMT
Subject: Re: git status: small difference between stating whole repository and small subdirectory
Message-ID: <20120220140653.GC5131@sigill.intra.peff.net>
In-Reply-To: <CAA01CsozANwtox06iihKBL8iii175FHAhChmNhG1B0ofGKWcEA@mail.gmail.com>

On Mon, Feb 20, 2012 at 09:25:00AM +0100, Piotr Krukowiecki wrote:

> Is the cache set? Not sure how to check it. t0090-cache-tree.sh uses
> test-dump-cache-tree and executes "read-tree HEAD" to establish the
> cache, but in my case read-tree does not make the cache dumpable (but
> it improves status performance).
> 
> $ test-dump-cache-tree  | wc -l
> 0
> $ git read-tree HEAD
> $ test-dump-cache-tree  | wc -l
> 0
> $ echo 3 | sudo tee /proc/sys/vm/drop_caches && time git status -- .
> [...]
> real	0m1.085s

Hmm. I would think test-dump-cache-tree would do it. I don't know why
read-tree wouldn't fill it in, though.

Interestingly, on my git.git repo, I had an empty cache. Running "git
read-tree HEAD" filled it (according to test-dump-cache-tree). It seems
that running "git checkout" empties the cache.  So perhaps git could do
better about keeping the cache valid over time.

-Peff