bug#69263: 29.1; emacs freeze with memory swap

[Eli Zaretskii <eliz@gnu.org>]

tags 69263 moreinfo
thanks

> From: awrhygty@outlook.com
> Date: Mon, 19 Feb 2024 14:56:10 +0900
> 
> 
> My PC has 8GB memory and HDD, no SSD.
> Emacs freezes with the procedure below.
> 
> (0) Close all applications.
> (1) Start task manager.
>     Confirm disk usage is low and memory usage is about 2GB or less.
> (2) Start emacs -Q
> (3) Evaluate the form below
>       (progn (make-string (* 8000 1000 1000) 0)
>              (kill-emacs))
> (4) Memory usage increases and then decreases in ten seconds.
> (5) Disk usage keep 100% active for a few minutes.
> (6) Application window of emacs keep alive and emacs process name is
>     displayed in the process tab of task manager.
>     (At least 10 hours, I waited.)

I don't have a 8GB 64-bit Windows system to try this, and the results
are likely to be dependent on the intimate details of the Virtual
Memory setup on that system.

So if you want to help us understand what happens in the strange case
where a Lisp program creates a 8GB Lisp string, and clear it all, on a
8GB MS-Windows system, please attach GDB to Emacs after running the
above recipe, and produce a backtrace that can be used to try to
figure out what happens.  (I hope that your Emacs binary is not
stripped of debugging symbols, because if it's stripped, GDB will not
tell anything useful.)

Thanks.