GNU bug report logs - #42482
27.0.91; emacs modules memory leak

Previous Next

Full log

Message #10 received at 42482-done <at> debbugs.gnu.org (full text, mbox):

From: Philipp Stephani <p.stephani2 <at> gmail.com>
To: Milan Stanojević <mstanojevic <at> janestreet.com>
Cc: 42482-done <at> debbugs.gnu.org
Subject: Re: bug#42482: 27.0.91; emacs modules memory leak
Date: Thu, 23 Jul 2020 14:06:57 +0200

Am Do., 23. Juli 2020 um 01:27 Uhr schrieb Milan Stanojević
<mstanojevic <at> janestreet.com>:
>
> env-make_global_ref adds a reference to the underlying Lisp_Object
> and allocates emacs_value from the global storage. env->free_global_ref
> on the other hand will only remove a reference to the underlying
> Lisp_Object and not free the emacs_value.
>
> Here is a simple recipe to reproduce the problem (I only tested this
> on linux). I'm attaching the necessary files.
>
> $ gcc -shared -fpic -std=c99 -I <dir-with-emacs-module.h>
> create_global_refs.c -o create_global_refs.so
> $ emacs --no-splash -q -l create_global_refs.so -l create_global_refs_test.el
>
> If you look at the memory usage of emacs (for example in htop) you'll
> see that with emacs-26 it is constant but with emacs-27 the resident
> memory quickly grows.

Thanks for the report. I've fixed this in commit
5c5eb9790898e4ab10bcbbdb6871947ed3018569; the fix is slightly
different from what you proposed in that it stores the emacs_value
object in the global references hashtable, but it should have the same
effect. At least I can't reproduce the symptom any more after that
commit.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.