From: Nguyen Thai Ngoc Duy <pclouds@gmail.com>
Date: Sat, 24 Dec 2011 10:55:14 GMT
Subject: Re: [PATCH v2 3/3] grep: disable threading in all but worktree case
Message-ID: <CACsJy8DbfE8r3KsxCnb30-sb3LUAAWapAKJUSJ1zBZme1FoMwg@mail.gmail.com>
In-Reply-To: <20111224070715.GA32267@sigill.intra.peff.net>

(Sorry I replied without reading though the mail)

On Sat, Dec 24, 2011 at 2:07 PM, Jeff King <peff@peff.net> wrote:
> The case where we would most expect the setup cost to be drowned out is
> using a more complex regex, grepping tree objects. There we have a
> baseline of:
>
>  $ time git grep 'a.*c' HEAD >/dev/null
>  real    0m5.684s
>  user    0m5.472s
>  sys     0m0.196s
>
>  $ time git ls-tree --name-only -r HEAD |
>      xargs git grep 'a.*c' HEAD -- >/dev/null
>  real    0m10.906s
>  user    0m10.725s
>  sys     0m0.240s
>
> Here, we still almost double our time. It looks like we don't use the
> same pathspec matching code in this case. But we do waste a lot of extra
> time zlib-inflating the trees in "ls-tree", only to do it separately in
> "grep".

I assume this is gree_tree(), we have another form of pathspec
matching here: tree_entry_interesting() and it's still a bunch of
strcmp inside. Does strcmp show up in perf report?
-- 
Duy