bug#1053: 23.0.60; 600 MB memory not freed after keyboard-quit

[Stefan Monnier]

> could move the point (with the arroy keys): I thought yyy-process is
> stopped and I can use Emacs again. But after a while Emacs again
> stopped responding. Even the buffer content was not redrawn. I tried

It was probably busy doing garbage-collection.

> C-g again and again, but nothing happened. I hoped just memory freeing
> takes a long time, so left my PC for some minutes. This didn't helped
> either. But after a while I could again use Emacs: killed the buffer
> (containing yyy) and moved around the point just to see it works. But
> memory still was occupied: Emacs used ~600MB. Later I killed Emacs
> (with C-x C-c) and got back the memory.

Releasing such memory is surprisingly difficult, so you may indeed end
up with a large Emacs process with a large heap that takes a long time
to GC, so every time Emacs calls the GC your Emacs appears frozen.

If you try M-: (garbage-collect) RET in such a process you should see
how long it takes, and the returned value contains useful info to have
a vague idea of what's going on.


        Stefan