Bug 429725

Summary:	Parallelize thumbnail generation on multicore systems
Product:	[Frameworks and Libraries] kio-extras	Reporter:	Florian Dittmer <kde-bugs>
Component:	Thumbnails and previews	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	REPORTED ---
Severity:	wishlist	CC:	kfm-devel, nate, postix
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Florian Dittmer 2020-11-27 15:19:01 UTC

SUMMARY

I have folders with lots of images. My system is a modern 8core/16thread Ryzen with NVMe storage and 32GB of RAM. When opening a folder in "thumbail view" for the first time, Dolphin will start thumbnail generation. Looking at the "top" output, I can only see one thumbnail.so process while most of the CPU cores are idle.

Is it possible to parallelize the thumbnail generation to make it faster? E.g. when opening a folder with 100 images, why not divide them and start X threads of the thumbnail generator in parallel? Number of threads could be calculated based on number of cores/threads and/or made configurable to fit user needs.


STEPS TO REPRODUCE
1. Open folder with logs of images in Dolphin in icon/thumbnail mode
2. Look at top/ps -> only one thumbnail.so process processing sequentially the directory, other cpu cores idle.
3. 

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Operating System: Gentoo Linux
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.15.1
Kernel Version: 5.9.11
OS Type: 64-bit
Processors: 16 × AMD Ryzen 7 3700X 8-Core Processor
Memory: 31.4 GiB of RAM
Graphics Processor: AMD Radeon RX 5700 XT

ADDITIONAL INFORMATION