Hello Gilles and other, I am writing this bug report more to gather answers. While the behavior is buggy, you typical grounds some may not ack this as a bug report. top - 19:22:47 up 1:22, 1 user, load average: 2.46, 2.47, 2.66 Tasks: 280 total, 1 running, 279 sleeping, 0 stopped, 0 zombie %Cpu0 : 0.0 us, 0.0 sy, 0.0 ni,100.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu1 : 1.0 us, 1.0 sy, 0.0 ni, 98.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu2 :100.0 us, 0.0 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu3 : 2.0 us, 0.0 sy, 0.0 ni, 98.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st MiB Mem : 7908.926 total, 54.078 free, 7101.984 used, 752.863 buff/cache MiB Swap: 8579.996 total, 8229.297 free, 350.699 used. 426.590 avail Mem Change delay from 1.0 to PID PPID nTH USER PR NI S %CPU %MEM TIME+ COMMAND UID 15220 1 22 rrs 20 0 S 25.0 72.7 42:36.95 digikam 1000 10567 10565 2 rrs 20 0 S 0.2 0.7 1:04.03 Xorg 1000 10912 10555 4 rrs 20 0 S 0.2 0.3 0:25.02 gnome-terminal- 1000 18604 2 1 root 20 0 S 0.2 0:01.35 kworker/2:2 0 The problem with the current digikam/libkface implementation is 2 fold. First, it blocks so much memory. I think most of it is reclaimable as needed. But the other problem, of not using all available cores, is more annoying. It ends up taking way more time than necessary. PS: Yes. I did select "Work on all cores" in the Advanced Tab. Reproducible: Always Steps to Reproduce: 1. Scan collection for faces 2. Ensure "Work on all cores" is selected 3. Start the scan Actual Results: Memory Consumption spikes. Only 1 processor core is in use. Expected Results: Memory consumption shouldn't spike All available cores should be used, perhaps with a slightly higher nice level
yes libkface interface is multithreaded. In libkface/tests, you will found CLI tool to check multicores-multithreads processing with the library. In digiKam, face management use multicores-multithreads interface. About the memory consumption, this is already fixed with recent libkface provided with last KDE4 release. Gilles Caulier
*** This bug has been marked as a duplicate of bug 338176 ***
Problem is fixed with new 7.0.0-beta1 through this long story from this bug https://bugs.kde.org/show_bug.cgi?id=399923 You can test digiKam 7.0.0-beta1 with bundle available here: https://download.kde.org/unstable/digikam/ Don't hesitate to give us a fresh feedback about his entry. Thanks in advance Gilles Caulier