520577 2026-05-23 20:23:03 +0000 Navigating in thumbnails/preview uses 100% of main thread for 10-15 seconds on each selection change 2026-05-24 03:55:34 +0000 1 1 2 Applications digikam Albums-ItemsGroup 9.0.0 Arch Linux Linux RESOLVED FIXED NOR normal --- 0 saveliy.v.vasilev digikam-bugs-null caulier.gilles saveliy.v.vasilev 9.1.0 0 oldest_to_newest 2517964 0 saveliy.v.vasilev 2026-05-23 20:23:03 +0000 DESCRIPTION Changing a single-picture selection within folder with grouped JPG and NEF files halts the main thread for 10-15 seconds STEPS TO REPRODUCE 1. Select all files in a folder (~1400 files, 21GB) 2. Right click -> Group -> Group Selected by Filename (resulting in ~700 groups since I shoot NEF+JPG) 3. Go to either preview or remain in thumbnails view, change selection with arrows 5-10 times OBSERVED RESULT DigiKam becomes unresponsive, the main thread goes to 100% CPU usage for 10-15 seconds On any subsequent selection change the same happens -- rendering the experience unusable EXPECTED RESULT Works as if the files were not grouped SOFTWARE/OS VERSIONS Operating System (available in the Info Center app, or by running `kinfo` in a terminal window): KDE Plasma Version: 6.6.5 KDE Frameworks Version: 6.26.0 Qt Version: 6.11.1 Kernel Version: 7.0.9-arch2-1 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 PRO 7840U w/ Radeon 780M Graphics Memory: 64 GiB of RAM (58.6 GiB usable) Graphics Processor: AMD Radeon 780M Graphics ADDITIONAL INFORMATION When the main thread shows 100% usage, below is the gbd backtrace for Thread#1, the Thread#1 is consistently stuck in that state during the unresponsive period. The rest of the threads are waiting with different calls (ppoll, epoll, etc) Thread 1 (Thread 0x7f1520e36cc0 (LWP 57817) "digikam"): #0 0x00007f154e49bb18 in ??? () at /usr/lib/libQt6Core.so.6 #1 0x00007f154e4aa2ee in QtPrivate::QStringList_contains(QList<QString> const*, QStringView, Qt::CaseSensitivity) () at /usr/lib/libQt6Core.so.6 #2 0x00007f15505095e6 in ??? () at /usr/lib/libdigikamcore.so.9.0.0 #3 0x00007f1550511dc0 in Digikam::LoadingCache::putThumbnail(QString const&, QPixmap const&, QString const&) () at /usr/lib/libdigikamcore.so.9.0.0 #4 0x00007f15504f158c in Digikam::ThumbnailLoadThread::slotThumbnailLoaded(Digikam::LoadingDescription const&, QImage const&) () at /usr/lib/libdigikamcore.so.9.0.0 2517973 1 caulier.gilles 2026-05-23 20:53:36 +0000 This problem must be fixed in 9.1.9 pre-release available as AppImage bundle here : https://files.kde.org/digikam/ 2517986 2 saveliy.v.vasilev 2026-05-23 22:24:51 +0000 Confirming it works, thanks a lot!