[Digikam-users] svn version memory usage

D Bera dbera.web at gmail.com
Sat Oct 14 20:13:51 BST 2006

On 9/27/06, Marcel Wiesweg <marcel.wiesweg at gmx.de> wrote:
> Hi,
> here are some numbers of current svn.

Sorry, I couldnt get back earlier. Recently I synced to svn and after
trying to show off some pictures to friends, I got extremely
frustrated. Unlike 0.8.x series, 0.9.x series is not that snappy and
lightweight. Specially when you double click a thumbnail to see an
image. As I am writing this email, I am rebuilding digikam with -g and
then intend to run valgrind on that.
Read my response inline below.

> First using exmap (which is, according to Lubos Lunak's blog, the tool to be
> used to measure memory usage)
> Pixmaps are stored in the X server, so the memory usage of X is given as well.
> First number is "Effective resident" which is - as there was no swapping -
> the effective memory usage in KB.
> It is made up of executable code (which can be reduced by stripping) and two
> other numbers, "heap" and "anon", no definition from me, both are given here.
> Before start
>         X 17929 heap 13644 anon 1427
> digikam first
>         X 23537 heap 13644 anon 6051
>         digikam 31574 heap 7152 anon 3228
> digikam thumbnail cache
>         X 27153 heap 17260 anon 6051
>         digikam 31556 heap 7164 anon 3228
> (-> 100 pixmaps stored in the server)
> digikam image editor one image
>         X 34525 heap 18992 anon 11687
>         digikam 71146 heap 9096 anon 40592
> (-> widget, canvas and image data of one image, pixmaps)
> digikam image editor cache full
>         X no significant change
>         digikam 120500 heap 9220 anon 89764
> (-> 40MB DImg cache)
> digikam image editor closed (cache still full)
>         X no significant change
>         digikam 108336, heap 9240 anon 77472
> digikam closed
>         X 21900 heap 17616 anon 431

"cache still full"  - which cache is this ? DImg ?
Why is the dimg cache not cleared when the editor is closed ? Is that
for performance reason ? As a result, if I keep open digikam after
viewing a few images, it will keep blocking that 40MB memory ?
I guess what I am asking is why isnt the memory usage after
image-editor same as that before ? I might be ok when I am using
image-editor since I understand it has to do lots of things, but when
I close it, things should be back to normal. (BTW, the image-editor
felt much snappy in 0.8.x series, dunno what changed).

> Second, using valgrind's massif tool.
> The attached chart was taken with a similar run as above.
> Colors #1 and #2 represent memory used by DImg.
> With the exception of the 45MB peak of "other", the cause of which I don't
> know, and QImage::create, which is probably the preview feature, what you can
> see from this is that the real large part of memory is used for image
> editing.

I am sorry I didnt quite understand the conclusion :(. Are you saying
that the memory usage is normal(read: as expected) or agreeing that
there is a leak worth investigating?
- dBera

Debajyoti Bera @ http://dtecht.blogspot.com
beagle / KDE fan
Mandriva / Inspiron-1100 user

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