Re: Mercurial 0.4b vs git patchbomb benchmark

From: Matt Mackall <mpm@selenic.com>
Date: Apr 30, 2005, 16:06 UTC
Message-ID: <20050430160640.GK21897@waste.org>
In-Reply-To: <200504301444.j3UEiHN05686@adam.yggdrasil.com>

On Sat, Apr 30, 2005 at 07:44:17AM -0700, Adam J. Richter wrote:

Show 13 quoted lines

>
> 	I'd like to mention a couple of possible optimizations
> for both the with and without compression approaches.
> 
> 	If you remove the gzip compression, then I imagine you could
> do much of the IO of checking out files via sendfile, without
> ever copying data to program space or even changing the program's
> memory map.  There apparently exists a python sendfile module.
> 
> 	If this mercurial were written in C, much of the rest of
> the IO could be optimized with mmap (to reduce copies) and writev
> in the absense of a compression pass.  I don't know enough about
> python to know if these optimizations are available.

Python can do mmap, not sure about writev.

But I'm currently still in the "keep it as simple as possible" stage. There's a bunch of room for optimization still, but if I do it all now, it'll make things hard when I run into the next design change.

And there's still some important core work that needs doing - checkout and commit need to be a subcase of the core merge code.

-- 
Mathematics is the supreme nostalgia of our time.