Re: info -w is slow for man pages

[Eli Zaretskii]

> Date: Sat, 15 Oct 2022 23:58:53 +0200
> From: Hilmar Preusse <hille42@web.de>
> 
> I noticed that "info -w" is puzzlingly slow when the argument is a man page:
> 
>     $ time -p info -w ffmpeg-all
>     *manpages*
>     real 1.06
>     user 1.47
>     sys 0.16
> 
> In contrast, "man -w" is near-instantaneous:
> 
>     $ time -p man -w ffmpeg-all
>     /usr/share/man/man1/ffmpeg-all.1.gz
>     real 0.05
>     user 0.04
>     sys 0.01
> 
> Apparently this is because "info -w" calls "man -a", which is a very 
> inefficent way to check if a man page exists:
> 
>     $ strace -f -e trace=execve -o '| grep -w man >&2' info -w ffmpeg-all > 
> /dev/null
>     1142  execve("/usr/bin/man", ["/usr/bin/man", "-a", "ffmpeg-all"], 
> 0xfffd7dd4 /* 52 vars */) = 0
> 
> The issue was reported for texinfo 6.8, but is reproducible w/ latest
> checkout the git master. Please keep me in Cc, I'm not subscribed to
> the list.

I'm not a Texinfo maintainer, so this isn't my decision to make, but
Info shows man pages only as the last resort.  As such, I'm not sure
we should worry about minor inefficiency in that last-resort case.
The main job of Info is to display the Info manuals.