On ppc64 el host, SMT is not set at off upon reboot
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Nova Compute Charm |
Triaged
|
Medium
|
Unassigned |
Bug Description
Following a hardware issue on a ppc64el host, the server was restarted.
However, upon reboot, smt was not set as off, given that no juju changed had occurred, the hooks were not run.
As a result, qemu was not happy:
"""
2019-05-
error: kvm run failed Device or resource busy
This is probably because your SMT is enabled.
VCPU can only run on primary threads with all secondary threads offline.
"""
I created this little systemd unit to do the trick upon reboot:
"""
[Unit]
Description=Set SMT to off
After=network.
Before=
[Service]
Type=oneshot
ExecStart=
ExecStop=
RemainAfterExit
StandardOutput=
[Install]
WantedBy=
"""
But it would be better to have a way to turn it on or off at boot time, not only during hooks, based on option and/or architecture
At least on ppc64el, it should be turned off permanently.
Regards,
This is a bit of a fallout from the change in behaviour in Juju which means config-changed only runs after something actually changes - a reboot no longer triggers this hook.