It's a regression from xenial and took a few weeks to appear on bionic. I tried using lock_page_killable() in __unmap_and_move() but as far as I can tell kcompactd0 hasn't got stuck in the same way. Instead I now have every btrfs_start_transaction suddenly blocking for all processes, which is impossible to debug because I can't even login.
I've installed the 5.4 HWE kernel instead because 4.15 is just unusable on two hosts. ** Attachment added: "Screenshot from 2020-08-25 08-03-16.png" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891773/+attachment/5408793/+files/Screenshot%20from%202020-08-25%2008-03-16.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1891773 Title: kcompactd0 and btrfs-transaction keep deadlocking with each other To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891773/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs