openstack/nova
Code Issues Proposed changes

compute: introduce cpu_shared_set option

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The CONF.compute.cpu_shared_set option will be used for best-effort
guest vCPU resources.

It's to note that an other effort done by spec cpu-resources will use
that same option to provide isolation between dedicated and shared
instances. But currently outside of the scope of that whole serie.

Change-Id: Ibedd31e284ec9bc70e257e6a88b4d82b021db0fd
Partial-implement: bp/overhead-pin-set
Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@redhat.com>
This commit is contained in:
Sahid Orentino Ferdjaoui
2018-04-17 07:04:26 -04:00
parent 50f42333f5
commit 30cda5113c
3 changed files with 41 additions and 0 deletions
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11
nova/conf/compute.py
View File

@@ -655,6 +655,17 @@ node.
Possible values: Possible values:
* Any positive integer in seconds. * Any positive integer in seconds.
"""),
cfg.StrOpt('cpu_shared_set',
help="""
Defines which physical CPUs (pCPUs) will be used for best-effort guest vCPU
resources.
Currently only used by libvirt driver to place guest emulator threads when
hw:emulator_threads_policy:share.
::
cpu_shared_set = "4-12,^8,15"
""") """)
] ]

14
nova/tests/unit/virt/test_hardware.py
View File

@@ -61,11 +61,25 @@ class CpuSetTestCase(test.NoDBTestCase):
cpuset_ids = hw.get_vcpu_pin_set() cpuset_ids = hw.get_vcpu_pin_set()
self.assertEqual(set([1, 3, 5]), cpuset_ids) self.assertEqual(set([1, 3, 5]), cpuset_ids)
def test_get_cpu_shared_set(self):
self.flags(cpu_shared_set="0-5,6,^2", group='compute')
cpuset_ids = hw.get_cpu_shared_set()
self.assertEqual(set([0, 1, 3, 4, 5, 6]), cpuset_ids)
def test_parse_cpu_spec_none_returns_none(self): def test_parse_cpu_spec_none_returns_none(self):
self.flags(vcpu_pin_set=None) self.flags(vcpu_pin_set=None)
cpuset_ids = hw.get_vcpu_pin_set() cpuset_ids = hw.get_vcpu_pin_set()
self.assertIsNone(cpuset_ids) self.assertIsNone(cpuset_ids)
def test_parse_cpu_shared_set_returns_none(self):
self.flags(cpu_shared_set=None, group='compute')
cpuset_ids = hw.get_cpu_shared_set()
self.assertIsNone(cpuset_ids)
def test_parse_cpu_shared_set_error(self):
self.flags(cpu_shared_set="0-1,^0,^1", group='compute')
self.assertRaises(exception.Invalid, hw.get_cpu_shared_set)
def test_parse_cpu_spec_valid_syntax_works(self): def test_parse_cpu_spec_valid_syntax_works(self):
cpuset_ids = hw.parse_cpu_spec("1") cpuset_ids = hw.parse_cpu_spec("1")
self.assertEqual(set([1]), cpuset_ids) self.assertEqual(set([1]), cpuset_ids)

16
nova/virt/hardware.py
View File

@@ -54,6 +54,22 @@ def get_vcpu_pin_set():
return cpuset_ids return cpuset_ids
def get_cpu_shared_set():
"""Parse cpu_shared_set config.
:returns: a set of pcpu ids can be used for best effort workloads
"""
if not CONF.compute.cpu_shared_set:
return None
shared_ids = parse_cpu_spec(CONF.compute.cpu_shared_set)
if not shared_ids:
raise exception.Invalid(_("No CPUs available after parsing "
"cpu_shared_set config. %r ") %
CONF.compute.cpu_shared_set)
return shared_ids
def parse_cpu_spec(spec): def parse_cpu_spec(spec):
"""Parse a CPU set specification. """Parse a CPU set specification.