bug#67672: EMACS - Slow opening files

[Eli Zaretskii]

> From: "Moore, Rider" <rmoore@cooley.com>
> CC: "Chand, Suresh" <schand@cooley.com>,
>         "67672@debbugs.gnu.org"
>       <67672@debbugs.gnu.org>
> Date: Tue, 12 Dec 2023 15:52:53 +0000
> 
> The delay is only present for files located within the Truecrypt volume we 
> are using (essential for our purposes).

OK, this is good to know, thanks.

> Do you know of any commands or settings adjustments needed when working with 
> a Emacs and a Truecrypt volume?

No, I don't.  I don't think we have ever heard about problems with
these particular volumes.  Which is why I suggested to run this slow
operation under perf, which will allow you to produce a profile of the
code, and hopefully will show us which part of the code is the
bottleneck.  I don't think we can make any progress here unless we
understand which parts of the code are slow when opening files on
Truecrypt volumes.

Another, less convenient method is to step in a debugger through the
code in find-file and its subroutines, and see which part(s) there
take such a long time.  Presumably, if this takes minutes, you should
be able to identify the calls that take such a long time.

As a "leap of faith", how about timing the following, after starting
"emacs -Q":

  M-: (insert-file-contents "SOME-FILE") RET

where SOME-FILE is a file on a Truecrypt volume.  Does the above take
an abnormally long time, or is it as fast as when you do the same with
a file on any other volume?