Re: [emacs_user@hotmail.com: reproducible cygwin memory problems]

[David Kastrup <dak@gnu.org>]

Richard Stallman <rms@gnu.org> writes:

> Would someone please help him investigate this -- then ack this message?
>
> Are the images kept in a cache?  Is there a way to clear it?
>

They are, and he does already clear the cache:

> after killing the buffer with the image and using
> M-:(clear-image-cache t)RET: 16476;

Incidentally, the cache is there since we are very inefficient turning
image data into images: it would probably make sense to let gdk (or
equivalent code working on entire images) handle this where available
(the main problem is that the conversion is done pixel-by-pixel).

But that is a long-standing peeve of mine, and certainly not something
to be tackled for Emacs 22.

The memory issues, however, are a different thing.  I guess it might
be because image data gets allocated by xmalloc, out of Emacs' memory
pool.  xmalloc would not be able to make use of previous small memory
allocations.

> after editing a large image: 39164;
>
> again quit+clear cache: 34484;
>
> edit small+medium+large images: 58936;
>
> quit+clear: 87636...  (increased!)
>
> I hope someone can look into this, and I am happy to provide
> information given specific instructions.
>
> thanks...  EU
>
>
> In GNU Emacs 22.0.50.1 (i686-pc-cygwin, X toolkit, Xaw3d scroll bars)
> of 2006-07-31 on cata2

The problem might be related to the "malloc" or equivalent memory
allocation strategy that is available on a copmilation for Cygwin.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum