From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 01 Feb 2012 16:28:46 GMT
Subject: Re: [PATCH] Don't search files with an unset "grep" attribute
Message-ID: <7vd39y4iwx.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20120201091009.GA20984@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Part of the problem, I suspect, is that the attribute lookup code is
> optimized for locality. We only unwind as much of the stack as we need,
> so looking at "foo/bar/baz.c" after "foo/bar/bleep.c" is much cheaper
> than looking at "some/other/directory.c". But with threaded grep, that
> locality is likely lost, as we are mixing up attribute requests from
> different threads.
>
> Given that binary lookup means we need every file's gitattribute, it
> might be better to look them up serially at the beginning of the
> program, and then pass the resulting userdiff driver to grep_buffer
> along with each path.

Yeah, that was my impression when the performance of threaded grep was
discussed, which was before this "let's honor binary attribute".