Spent some time analyzing this. Frank loaned me a test system. The test system in the "idle" state is enough to see the issue, with a persistent load of 3+ when nothing is happening except event loop spin. The test system is using a dasd as the disk that it is running from.
With some udev tracing, one can see an apparent loop, with udisks2 opening /dev/dasda, which triggers an inotify, which triggers udev rules, which trigger udisks2 again, or something similar to this flow. Workarounds include: * adding a nowatch rule 'ACTION=="add|change", KERNEL=="dasd*", OPTIONS:="nowatch"' * systemctl stop udisks2 I've begun exploring udev changes for udisks2 to ignore dasd. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/2037569 Title: udev issues with mantic beta Status in Ubuntu on IBM z Systems: New Status in systemd package in Ubuntu: Confirmed Status in udisks2 package in Ubuntu: Confirmed Bug description: While installing mantic beta (on s390x, LPAR and z/VM - but this might not be architecture specific) I faced issues with udev. In my installation I've updated the installer to "edge/lp-2009141" (subiquity 22.02.2+git1762.1b1ee6f4 5164). During my installations I first noticed bad response times in case of dealing with devices (like enabling new devices with chzdev). chzdev is used during the installation, hence the installation procedure is also affected by this. (I mainly notice this issue in case of DASD ECKD disk enablements.) But even after after a successful (but due to this issue less snappier) installation, means after the post-install reboot, in the installed system I can find several udev related processes, like: 69448 root 20 0 31280 11944 2560 S 39.2 0.0 2:51.67 (udev-worker) 509 root 20 0 31276 13812 4600 S 20.6 0.0 2:07.76 systemd-udevd 893 root 20 0 469016 13544 10496 R 17.3 0.0 1:43.53 udisksd 1 root 20 0 168664 12748 8396 S 16.3 0.0 1:40.47 systemd which is not only unusual, but (as one can see) they consume quite some resources. Even the remote ssh into that system is impacted by this high load. So far I only see this in mantic. I tried 20.04.3 as well as lunar, but both do not seem to be affected by this udev problem. I neither face the bad response on device enablement, nor can see any udev related processes still running after post-install-reboot in the installed system. (Sometimes I could also see a growing log file 'syslog'). I cannot say yet what is causing this, but since I see 'systemd-udevd' as prominent process in top, I'll first of all mark this as affecting systemd-udevd (or systemd). I've attached the outcome of some more investigations I did ... To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2037569/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
