Subject: bug#71094: [PATCH] Prefer to run find and grep in parallel in rgrep

From: Dmitry Gutov <[email-masked]>
Date: Wed, 22 May 2024 20:47:57 +0300

On 22/05/2024 18:26, Eli Zaretskii wrote:

> I'd be happy if someone could time these methods on MS-Windows and on
> some *BSD system, at least.  Bonus points for macOS.

As luck would have it, I have an M3 Pro macOS laptop around.

The situation with it is odd, as usual. First of all, the default 
find/xargs/grep installed are some very slow versions from Apple.

The patch doesn't seem to change the performance of the search using 
them, it's just slow either way.

Things get better if I install the GNU versions from Homebrew and

    (setq grep-program "ggrep")

at startup. Performance gets better by 4x or so just from that, but 
still not to the level of my 5-year-old GNU/Linux laptop. The patch 
doesn't seem to have a make a difference still. If I also set

    (setq xargs-program "gxargs")

then the patch starts improving performance in a large directory (again: 
Linux kernel), by around 10%. Still more than 3x slower than on my older 
laptop with Linux. No idea why - the ggrep, gxargs and gfind executables 
are all reported to be arm64, so I can't blame the x64->arm64 
translation layer.

To sum up though, the patch under discussion doesn't make things worse 
on the macOS laptop I tested.