Playing around with the now available IO schedulers does not appear to help much and looking at iotop while the test runs does show ext4lazyinit consuming much of the IO most of the time while the test runs.
I wonder if this is a more ominous change of behavior after all Total DISK READ: 0.00 B/s | Total DISK WRITE: 0.00 B/s Current DISK READ: 0.00 B/s | Current DISK WRITE: 22.22 M/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND 948 be/4 root 0.00 B/s 0.00 B/s 0.00 % 99.99 % [ext4lazyinit] 5651 be/4 root 0.00 B/s 0.00 B/s 0.00 % 99.99 % fio /usr~write.fio 22 be/4 root 0.00 B/s 0.00 B/s 0.00 % 94.61 % [kworker~-252:384] Reopening to get some take from kernel team on the change of IO schedulers and if this is an anticipated side effect and/or if any known regression surrounding the ext4lazyinit process. ** Changed in: linux (Ubuntu) Status: Invalid => New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1880943 Title: [focal] disk I/O performance regression To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1880943/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs