Bug 341161

Summary:	Utilize more than one CPU core
Product:	[Applications] okular	Reporter:	Richard Llom <richard.llom>
Component:	PDF backend	Assignee:	Okular developers <okular-devel>
Status:	RESOLVED DUPLICATE
Severity:	wishlist	CC:	rigo, rikudou__sennin, sebastian.englbrecht
Priority:	NOR	Keywords:	investigated, triaged
Version:	0.20.60
Target Milestone:	---
Platform:	Chakra
OS:	Linux
Latest Commit:		Version Fixed In:

Description Richard Llom 2014-11-21 14:09:48 UTC

Example PDF:
http://oneplus.net/downloads/presentations/oneplus-one-keynote.pdf
160 MB / 122 Slides

I wanted to view the above mentioned "heavy" presentation slide by slide. No fast scrolling through, but just a quick glance at every slide.
However this was not possible, because the rendering wasn't fast enough and I had to wait a little for each slide.

During the scrolling Okular used 100% CPU but only on one of my 4 CPU cores. So I was wondering if it wasn't possible to use more than one core?

My CPU: AMD Phantom X4 955 @ 3.2 GHz

Possible related bugs:
Okular:
bug 185908

Poppler: 
https://bugs.freedesktop.org/show_bug.cgi?id=50993

Comment 1 sebastian 2015-09-25 21:18:47 UTC

I think that you should vote on your bug. I am interested in your bug too

Comment 2 sebastian 2015-09-25 21:23:35 UTC

i am not a member, i too post my bugs

Comment 3 Rigo Wenning 2016-03-09 16:31:05 UTC

I can confirm this bug. I really wonder about okular's usage of the underlying framework. The QT framework should use all CPU

Comment 4 Sebastian 2018-11-17 20:21:03 UTC

Hey richard,

as you already noted yourself this is a very similar if not same wish as another wishlist report.

Unfortunately it seems that this is a very hard improvement that is not doable at the current state because the backends are not threadsafe.

I hope someone will someday work on this issue.
If you are interested yourself feel free to contribute and thank you very much for reporting this idea and trying to improve okular!

Note: I am no maintainer but from the KDE Bugsquad

*** This bug has been marked as a duplicate of bug 185908 ***