Re: [PATCH 0/5] A series of performance enhancements in the memihash and name-cache area

From: Jeff King <peff@peff.net>
Date: Feb 14, 2017, 22:03 UTC
Message-ID: <20170214220332.753i4tgclm62er4f@sigill.intra.peff.net>
In-Reply-To: <cover.1487071883.git.johannes.schindelin@gmx.de>

On Tue, Feb 14, 2017 at 12:31:46PM +0100, Johannes Schindelin wrote:

Show 9 quoted lines

> On Windows, calls to memihash() and maintaining the istate.name_hash and
> istate.dir_hash HashMaps take significant time on very large
> repositories. This series of changes reduces the overall time taken for
> various operations by reducing the number calls to memihash(), moving
> some of them into multi-threaded code, and etc.
> 
> Note: one commenter in https://github.com/git-for-windows/git/pull/964
> pointed out that memihash() only handles ASCII correctly. That is true.
> And fixing this is outside the purview of this patch series.

Out of curiosity, do you have numbers? Bonus points if the speedup can be shown via a t/perf script.

We have a read-cache perf-test already, but I suspect you'd want something more like "git status" or "ls-files -o" that calls into read_directory().

-Peff