Thank you Mike, I'll chime in on bug 1833322 in regard to reconsider it being default enabled.

Now back to this - in regard to the report here which is the more technical "the log is flooded by these messages".
I've looked at this at a few machines I had (I admit, mostly virtual ones where irqbalance isn't doing too much) and it is indeed easy to reproduce.

# Get a clean test system (needs more than 1 cpu or it will exit early):
$ lxc launch ubuntu-minimal-daily:n n-vm --ephemeral --vm -c limits.cpu=4 -c limits.memory=2GiB
$ lxc exec n-vm bash

# Install
# it is BTW no more default installed on cloud images :-)
$ apt install irqbalance

# Check log
$ journalctl -u irqbalance
root@n-vm:~# journalctl -u irqbalance
Jan 05 12:09:40 n-vm systemd[1]: Started irqbalance.service - irqbalance daemon.
Jan 05 12:09:40 n-vm irqbalance[987]: Prevent irq assignment to these isolated CPUs: 00000000
Jan 05 12:09:40 n-vm irqbalance[987]: Prevent irq assignment to these adaptive-ticks CPUs: 00000000
Jan 05 12:09:40 n-vm irqbalance[987]: Banned CPUs: 00000000
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 66 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 65 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 64 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 55 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 58 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 56 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 59 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 57 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 26 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 53 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 54 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 35 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 38 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 36 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 37 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 24 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 48 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 49 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 21 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 31 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 29 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 63 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 61 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 62 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 10 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 27 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 33 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 34 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 25 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 51 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 60 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 45 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 43 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 41 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 46 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 44 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 42 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 40 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 39 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 47 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 52 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 50 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 68 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 69 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 67 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 32 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 30 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 28 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 0 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 1 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 4 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 8 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 9 to database
Jan 05 12:09:40 n-vm irqbalance[987]: Adding IRQ 12 to database
Jan 05 12:09:40 n-vm irqbalance[987]: IRQ 10 is removed from interrupts_db.

Jan 05 12:10:10 n-vm irqbalance[987]: 
 Jan 05 12:09:50 n-vm irqbalance[987]: 
                                      
                                      
                                      -----------------------------------------------------------------------------
Jan 05 12:09:50 n-vm irqbalance[987]: Cannot change IRQ 38 affinity: Input/output error
Jan 05 12:09:50 n-vm irqbalance[987]: IRQ 38 affinity is now unmanaged                                     
                                      
                                      -----------------------------------------------------------------------------
Jan 05 12:10:20 n-vm irqbalance[987]: 
                                      
                                      
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Continues every 10 seconds