Re: git grep performance regression

From: Ross Lagerwall <rosslagerwall@gmail.com>
Date: Jan 15, 2013, 07:36 UTC
Message-ID: <20130115073628.GA647@hobo.wolfson.cam.ac.uk>
In-Reply-To: <CACsJy8AnABCisgSVL7Qh_-uejAJA3x1kzy=4i+uXm3+90m5tuA@mail.gmail.com>

On Tue, Jan 15, 2013 at 11:38:32AM +0700, Duy Nguyen wrote:

Show 6 quoted lines

> dirlen is not expected to include the trailing slash, but
> find_basename() does that. It messes up with the path filters for
> push/pop in the next code. This brings grep performance closely back
> to before for me. Ross, can you check (patch could be whitespace
> damaged by gmail)?
>

Yes, that did seem to bring back the performance to the old level.

I noticed that before the patch, the strace output was something like this: open("tools/vm/.gitattributes", O_RDONLY) = -1 ENOENT open("tools/vm//.gitattributes", O_RDONLY) = -1 ENOENT open("tools/vm//.gitattributes", O_RDONLY) = -1 ENOENT open("tools/vm//.gitattributes", O_RDONLY) = -1 ENOENT open("usr/.gitattributes", O_RDONLY) = -1 ENOENT open("usr//.gitattributes", O_RDONLY) = -1 ENOENT open("usr//.gitattributes", O_RDONLY) = -1 ENOENT open("usr//.gitattributes", O_RDONLY) = -1 ENOENT open("usr//.gitattributes", O_RDONLY) = -1 ENOENT open("usr//.gitattributes", O_RDONLY) = -1 ENOENT

(and yes, the whitespace was damaged by Gmail!)

Regards

-- 
Ross Lagerwall