SUMMARY I am using a workstation which had been extremely performant (see SW and HW below) and is now extremely slow and not responsive due to letting Inotify increase its limits. I installed Kubuntu 26.04.2 just to see it is not my HW but KDE 6. STEPS TO REPRODUCE 1. KDE neon 6.3.5 - updated 2. having 8 virtual desks and more the 100 konsole windows with login shell (see screenshot) 3. increase limits as desired by Inotify OBSERVED RESULT System is no longer responsive ... games are unplayable ... even TeXLive is slow. EXPECTED RESULT System should be working as fast as before and no more "increase limits" calls by Inotify would be seen. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE neon 6.3.5 (24.04.2 based/Noble) - up-to-date KDE Plasma Version: 6.3.5 KDE Frameworks Version: 6.14.0 Qt Version: 6.9.0 Gears: 25.4.2 Using X11 session (as Wayland has not even session save) HARDWARE: Silent Workstation, Zen 4: Ryzen 9 7900, RDNA 3: Radeon RX 7800 XT, ASUS ROG STRIX X670E‑E, Kingston KSM48E40BD8KM‑32HM 64 GB DDR5‑ECC RAM, 3x Samsung EVOs 870 SATA III 4 TB, 2x Samsung 980 PRO Interne NVMe SSD 2 TB M.2 2280 PCIe 4.0. ADDITIONAL INFORMATION I am using 8 virtual desks - each with at least 9 - typically more - konsole windows with login shells - a professional workflow. This might be the cause for the trouble (due to KDE 6 not using resources efficiently as KDE 5 did it perfectly) and a screenshot of my desktop is seen here (<4kB attatchment is a joke): https://www.jmb-edu.de/images/KDE_Problem_with_holes_in_konsole_windows_showing_rectangular_parts_of_background_20250506_221202_medium.jpg to give you an impression of the desk and one can see visible problems (two rectangle showing background image an not the background of the konsole window) which may be related to this bug. As experienced Unix expert I thought a component is dying or a mitigation hit me ... would have never thought of a system going crazy for monitoting files. I just installed Kubuntu 24.04.2 and it works like a charm ... the oposite of the dead system KDE 6 created. Before KDE 6 was introduced, KDE neon was king - nearly perfectly configuered, fast, reliable - and with KDE 6 I could not even decide which bugs to report first. But now this is a game changer - if this is not revoked easily, KDE 6 is dead for me!
I thought "baloo" is an ill sevice which should be off by default - but at least I can swith that off in KDE settings ... Why is Inotify going crazy that way - and no warning presented. How can I revoke those bad things Inotify did when it increases the limit (3 times, I think - not sure - and still demanding the limit to be further increases!). It must severly disturb the kernel for such an extreme reaction - with 128 GB ECC memory! So like Baloo, Inotify and general file monitoring should never be started in that way and it should be asked if this is welcome with a warning about performance! And it is still crazy giving the same message: ~~ Inotify Instance Capacity Low You have too many applications wanting to monitor file changes! When the capacity is exhausted it will prevent further file monitoring from working correctly. Either close some applications or increase the limit. Currently using 90% of instances and 0% of watches. ~~ And I still wonder why any file should get monitored - this is no trusted system (i.e. hardened) and the only things monitored would bei root filesystem and memory for getting out of free space and causing some info that it is below ??%. But this is not done ... Any explanation what it is intended for and why it ruins a capable workstation that easy would be welcom. Especially how to revoce the ill things Inotify did so I can at least tests KDE 6 - I will work with the Kubuntu partition till KDE 6 is in a suitable situation like Debian Testing - currently KDE neon with KDE 6 is just unstable!
What's the output of kde-inotify-survey
You can see the output (from 18. May, so one month ago - but I think this should be the current situation - as I was busy to make sure my HW is not the culprit): https://www.jmb-edu.de/KDE_bug_with_inotify_survey.txt
What makes you think inotify is the problem. You are at "maxInstances": 256, which doesn't seem that wild considering the default is 128.
My system was fast - and it got slowed about the same time I agreed to extent the limit - even though I did not understand what it does and why. Additionally it asked again and again - and after some time it wants to further extent the limit. So from my perspective it goes crazy! Additionally I don't think that monitoring files is sane ... but mabe one could explain what inotify really does, why and how the changes are done. Currently it is not transparent for me ... Especially as the performance fell more severly than with my old Haswell system with huge mitigations happening in a few months (CPU and chipset graphics) ... so from my point of view if HW is ok which is proved by the other system - the kernel is sevrely limited under KDE6. And as KDE 6 is userspace, this should not be possible ... an extreme memory leak should be well known ... and this would result in some other effects and could be seen. So if Inotify is not the cause for trouble and KDE neon is not known to have problem with some similar AMD systems concerning performance I just have no guess. But I still think it is KDE 6 related - after I have seen Kubuntu with 5.27.12. KDE neon was terrific - a pleanat ride - till it switched to KDE 6 (which was started with 22.04 unfortunately; so no longer a working KDE neon for my new machine).
Run sudo mv -v /etc/sysctl.d/50-kde-inotify-survey* /root Then reboot and check if performance is back to normal.
Thanks for your help! I used the command as suggested: sudo su - mv -v /etc/sysctl.d/50-kde-inotify-survey* /root # renamed '/etc/sysctl.d/50-kde-inotify-survey-max_user_instances.conf' -> '/root/50-kde-inotify-survey-max_user_instances.conf' ... and after a reboot I tested the two games which were unpayable with KDE neon after allowing it to rise the limit 3x ... and now I can play them - so what inotify did IS really ugly - even though I must confess that Kubuntu 24.04 LTS is faster and more responsive. But maybe KDE 5 has a smaller footprint than KDE 6 - as KDE 6 is not that optimized yet? From what I saw KDE 6 is in alpha state - not ready to get tested by users ... KDE neon was so fast and responsive with KDE 5 - much better than Kubuntu 24.04.2 I use now - and I just installed it to proove KDE 6 as cuprit ... and that was right. For this bug report: I don't know why any file should be monitored at all. Root FS and Memory may be monitored and induce warnings ... these are the only two things which should be looked for. Well, another problem emerged as I thought everything was moved away, and so after a reboot and testing I was shocked to get another "Inotify Instance Capacity Low" message. So this message does not come from "/etc/sysctl.d/" but from the running KDE ??? From my point of view this should be switched off by default as baloo. But while baloo can at least be switched off, intotify is not even found in KDE search (i.e. Quick Setting - System Settings - `Search Field´). So how can I make sure this 'service' (I would rather regard it as malware) never runs on my KDE neon system again? And why has KDE 6 a problem on my oversized machine (see HW data given on "2025-06-17 13:23:58") but still thinks "capacity low" ??? There must be a fundamental problem - and I guessed that KDE developers don't test a system with more than 100 konsole windows each with login shell. That is my working style since 1993 for maximum user efficiency ... and KDE 6 may not be prepared to do that efficiently - while with KDE 5 this is no problem at all.
Please attach /etc/sysctl.d/50-kde-inotify-survey-max_user_instances.conf and /root/50-kde-inotify-survey-max_user_instances.conf to this bug report. Thanks./
As it was moved to /root the file '50-kde-inotify-survey-max_user_instances.conf' is only there: ~~ # This file was auto-generated by kde-inotify-survey. Manual changes will be overwritten. fs.inotify.max_user_instances=256 ~~
And if you move the file back I assume things are slow again?
This is certain - as more than 4 weeks the system was extremely slow. The question is how to stop innotification from doing harm to the system performance again.