Bug 436625 - Face detection: Unchecking "Work on all processor cores" still uses all cpu cores
Summary: Face detection: Unchecking "Work on all processor cores" still uses all cpu c...
Status: RESOLVED NOT A BUG
Alias: None
Product: digikam
Classification: Applications
Component: Faces-Detection (other bugs)
Version First Reported In: 7.2.0
Platform: Compiled Sources Linux
: NOR minor
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-05-05 12:36 UTC by Paul Krause
Modified: 2022-01-09 04:23 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In: 7.5.0
Sentry Crash Report:

Attachments
Terminal output with QT_LOGGING (17.67 KB, text/plain)
2021-05-05 12:36 UTC, Paul Krause 		Details
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Description Paul Krause 2021-05-05 12:36:55 UTC 
Created attachment 138165 [details]
Terminal output with QT_LOGGING

SUMMARY
Digikam uses all cores for face detection, regardless of the "Work on all processor cores" checkbox.


STEPS TO REPRODUCE
1. Goto "people" tab
2. Select "Detect faces"
3. Uncheck "Work on all processor cores" if is checked
4. Push "Scan collection for faces"


OBSERVED RESULT
Digikam uses all cores / as many threads as cores are avaible


EXPECTED RESULT
Only one core / thread is used


ADDITIONAL INFORMATION
Using the "YOLO v3" model or not does not matter.
Output of QT_LOGGING attached.
Thank you!
Comment 1 Maik Qualmann 2021-05-05 12:45:47 UTC 
Maybe we should change the label of the option, but we will definitely only start a face worker thread. Of course, e.g. internally OpenCV can use all processor cores for arithmetic operations, we have little influence on that. You can see that only one thread is started from this message:

digikam.general: Action Thread run  1  new jobs

Maik