Please enable the performance CPU governor

Bug #1732696 reported by James Troup
18
This bug affects 2 people
Affects Status Importance Assigned to Milestone
OpenStack Nova Compute Charm
Triaged
Medium
Unassigned

Bug Description

Please enable the performance CPU governor in the nova-compute charm or provide a charm option to do so. In our experience the powersave governor wastes a lot of CPU time on servers which are constantly busy¹ and that's often the case for compute nodes.

¹ There's details of this buried in LP #1579278

Tags: cpe-onsite
Revision history for this message
James Page (james-page) wrote :

James - do we want todo this more generally on charms that target hardware? i.e. is this applicable for ceph-osd and neutron-gateway as well?

Changed in charm-nova-compute:
status: New → Triaged
importance: Undecided → Medium
milestone: none → 18.02
Revision history for this message
James Troup (elmo) wrote : Re: [Bug 1732696] Re: Please enable the performance CPU governor

James Page <email address hidden> writes:

> James - do we want todo this more generally on charms that target
> hardware? i.e. is this applicable for ceph-osd and neutron-gateway as
> well?

In an unconverged setting it probably doesn't make as much sense for
ceph-OSD, IMO. I don't think ceph uses much CPU except during
rebulds. (And in converged, it'd be done by nova-compute, so it's
moot.)

OTOH, it definitely makes sense to do it on neutron-gateway, IMO.

--
James

Ryan Beisner (1chb1n)
Changed in charm-nova-compute:
milestone: 18.02 → 18.05
David Ames (thedac)
Changed in charm-nova-compute:
milestone: 18.05 → 18.08
James Page (james-page)
Changed in charm-nova-compute:
milestone: 18.08 → 18.11
tags: added: cpe-onsite
David Ames (thedac)
Changed in charm-nova-compute:
milestone: 18.11 → 19.04
James Page (james-page)
Changed in charm-nova-compute:
milestone: 19.04 → none
Revision history for this message
Haw Loeung (hloeung) wrote :

The Ubuntu distro default is 'performance':

| $ grep -E '^CONFIG_CPU_FREQ_DEFAULT' /boot/config-$(uname -r)
| CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y

FWIW, I have been able to set 'performance' by just disabling the 'ondemand' service with the following:

systemd:

| sudo systemctl mask ondemand.service

upstart:

| sudo update-rc.d ondemand disable

Of course, this requires rebooting unless you run something like:

| for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do sudo sh -c "echo performance > $i"; done

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