openstack
/
nova
Code Issues Proposed changes

Do not manage CPU0's state 

If cpu_power_management_strategy is "cpu_state" and CPU0 is in the
dedicated set, we should just ignore it whenever we go to manage the
state. Since CPU0 cannot be powered off, but may be otherwise suitable
for the dedicated set, we can just skip it whenever we would normally
go to power it up or down.

Change-Id: I995c0953b361c7016bd77482fa2e2f276d239828
Fixes-Bug: #2038840
This commit is contained in:
Dan Smith 2023-10-12 12:12:53 -07:00
parent 1e75373beb
commit 0b9d8cee58
4 changed files with 73 additions and 23 deletions
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75
nova/tests/unit/virt/libvirt/cpu/test_api.py
View File

@ -80,23 +80,23 @@ class TestAPI(test.NoDBTestCase):
@mock.patch.object(core, 'set_online')
def test_power_up_online(self, mock_online):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='1-2', group='compute')
api.power_up(self.fake_inst)
# only core #0 can be set as core #2 is not on the dedicated set
# only core #2 can be set as core #0 is not on the dedicated set
# As a reminder, core(i).online calls set_online(i)
mock_online.assert_called_once_with(0)
mock_online.assert_called_once_with(2)
@mock.patch.object(core, 'set_governor')
def test_power_up_governor(self, mock_set_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_power_management_strategy='governor', group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='1-2', group='compute')
api.power_up(self.fake_inst)
# only core #0 can be set as core #2 is not on the dedicated set
# only core #2 can be set as core #1 is not on the dedicated set
# As a reminder, core(i).set_high_governor calls set_governor(i)
mock_set_governor.assert_called_once_with(0, 'performance')
mock_set_governor.assert_called_once_with(2, 'performance')
@mock.patch.object(core, 'set_online')
def test_power_up_skipped(self, mock_online):
@ -113,23 +113,36 @@ class TestAPI(test.NoDBTestCase):
@mock.patch.object(core, 'set_offline')
def test_power_down_offline(self, mock_offline):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='1-2', group='compute')
api.power_down(self.fake_inst)
# only core #0 can be set as core #2 is not on the dedicated set
# only core #2 can be set as core #1 is not on the dedicated set
# As a reminder, core(i).online calls set_online(i)
mock_offline.assert_called_once_with(0)
mock_offline.assert_called_once_with(2)
@mock.patch.object(core, 'set_governor')
def test_power_down_governor(self, mock_set_governor):
def test_power_down_governor_cpu0_ignored(self, mock_set_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_power_management_strategy='governor', group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
api.power_down(self.fake_inst)
# only core #0 can be set as core #2 is not on the dedicated set
# Make sure that core #0 is ignored, since it is special and cannot
# be powered down.
mock_set_governor.assert_not_called()
@mock.patch.object(core, 'set_governor')
def test_power_down_governor(self, mock_set_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_power_management_strategy='governor', group='libvirt')
self.flags(cpu_dedicated_set='1-2', group='compute')
api.power_down(self.fake_inst)
# only core #2 can be set as core #0 is not on the dedicated set
# As a reminder, core(i).set_high_governor calls set_governor(i)
mock_set_governor.assert_called_once_with(0, 'powersave')
mock_set_governor.assert_called_once_with(2, 'powersave')
@mock.patch.object(core, 'set_offline')
def test_power_down_skipped(self, mock_offline):
@ -146,22 +159,22 @@ class TestAPI(test.NoDBTestCase):
@mock.patch.object(core, 'set_offline')
def test_power_down_all_dedicated_cpus_offline(self, mock_offline):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='0-2', group='compute')
api.power_down_all_dedicated_cpus()
# All dedicated CPUs are turned offline
mock_offline.assert_has_calls([mock.call(0), mock.call(1)])
# All dedicated CPUs are turned offline, except CPU0
mock_offline.assert_has_calls([mock.call(1), mock.call(2)])
@mock.patch.object(core, 'set_governor')
def test_power_down_all_dedicated_cpus_governor(self, mock_set_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_power_management_strategy='governor', group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='0-2', group='compute')
api.power_down_all_dedicated_cpus()
# All dedicated CPUs are turned offline
mock_set_governor.assert_has_calls([mock.call(0, 'powersave'),
mock.call(1, 'powersave')])
# All dedicated CPUs are turned offline, except CPU0
mock_set_governor.assert_has_calls([mock.call(1, 'powersave'),
mock.call(2, 'powersave')])
@mock.patch.object(core, 'set_offline')
def test_power_down_all_dedicated_cpus_skipped(self, mock_offline):
@ -192,9 +205,31 @@ class TestAPI(test.NoDBTestCase):
def test_validate_all_dedicated_cpus_for_cpu_state(self, mock_get_online,
mock_get_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_dedicated_set='0-1', group='compute')
self.flags(cpu_dedicated_set='1-2', group='compute')
self.flags(cpu_power_management_strategy='cpu_state', group='libvirt')
mock_get_online.return_value = True
mock_get_governor.side_effect = ('powersave', 'performance')
self.assertRaises(exception.InvalidConfiguration,
api.validate_all_dedicated_cpus)
@mock.patch.object(core, 'get_governor')
@mock.patch.object(core, 'get_online')
@mock.patch.object(api.LOG, 'warning')
def test_validate_all_dedicated_cpus_for_cpu_state_warning(
self, mock_warning, mock_get_online, mock_get_governor):
self.flags(cpu_power_management=True, group='libvirt')
self.flags(cpu_dedicated_set='0-2', group='compute')
self.flags(cpu_power_management_strategy='cpu_state', group='libvirt')
mock_get_online.return_value = True
mock_get_governor.return_value = 'performance'
api.validate_all_dedicated_cpus()
# Make sure we skipped CPU0
mock_get_online.assert_has_calls([mock.call(1), mock.call(2)])
# Make sure we logged a warning about CPU0
mock_warning.assert_called_once_with(
'CPU0 is in cpu_dedicated_set, but it is not eligible for '
'state management and will be ignored')

5
nova/tests/unit/virt/test_hardware.py
View File

@ -90,6 +90,11 @@ class CPUSetTestCase(test.NoDBTestCase):
cpuset_ids = hw.get_cpu_dedicated_set()
self.assertEqual(set([0, 1, 3, 4, 5, 6]), cpuset_ids)
def test_get_cpu_dedicated_set_nozero(self):
self.flags(cpu_dedicated_set='0-5,6,^2', group='compute')
cpuset_ids = hw.get_cpu_dedicated_set_nozero()
self.assertEqual(set([1, 3, 4, 5, 6]), cpuset_ids)
def test_get_cpu_dedicated_set__unset(self):
self.flags(cpu_dedicated_set=None, group='compute')
cpuset_ids = hw.get_cpu_dedicated_set()

5
nova/virt/hardware.py
View File

@ -76,6 +76,11 @@ def get_cpu_dedicated_set():
return cpu_ids
def get_cpu_dedicated_set_nozero():
"""Return cpu_dedicated_set without CPU0, if present"""
return get_cpu_dedicated_set() - {0}
def get_cpu_shared_set():
"""Parse ``[compute] cpu_shared_set`` config.

11
nova/virt/libvirt/cpu/api.py
View File

@ -81,7 +81,7 @@ def power_up(instance: objects.Instance) -> None:
if instance.numa_topology is None:
return
cpu_dedicated_set = hardware.get_cpu_dedicated_set() or set()
cpu_dedicated_set = hardware.get_cpu_dedicated_set_nozero() or set()
pcpus = instance.numa_topology.cpu_pinning
powered_up = set()
for pcpu in pcpus:
@ -101,7 +101,7 @@ def power_down(instance: objects.Instance) -> None:
if instance.numa_topology is None:
return
cpu_dedicated_set = hardware.get_cpu_dedicated_set() or set()
cpu_dedicated_set = hardware.get_cpu_dedicated_set_nozero() or set()
pcpus = instance.numa_topology.cpu_pinning
powered_down = set()
for pcpu in pcpus:
@ -127,7 +127,7 @@ def power_down_all_dedicated_cpus() -> None:
"power management if you only use shared CPUs.")
raise exception.InvalidConfiguration(msg)
cpu_dedicated_set = hardware.get_cpu_dedicated_set() or set()
cpu_dedicated_set = hardware.get_cpu_dedicated_set_nozero() or set()
for pcpu in cpu_dedicated_set:
pcpu = Core(pcpu)
if CONF.libvirt.cpu_power_management_strategy == 'cpu_state':
@ -144,6 +144,11 @@ def validate_all_dedicated_cpus() -> None:
governors = set()
cpu_states = set()
for pcpu in cpu_dedicated_set:
if (pcpu == 0 and
CONF.libvirt.cpu_power_management_strategy == 'cpu_state'):
LOG.warning('CPU0 is in cpu_dedicated_set, but it is not eligible '
'for state management and will be ignored')
continue
pcpu = Core(pcpu)
# we need to collect the governors strategy and the CPU states
governors.add(pcpu.governor)