commit 00e5e3a7443dd31720244497013b040729490dcd
Author: Eric Fried <email address hidden>
Date: Fri Feb 15 10:54:36 2019 -0600
Perf: Use dicts for ProviderTree roots
ProviderTree used to keep track of root providers in a list. Since we
don't yet have sharing providers, this would always be a list of one for
non-ironic deployments, or N for ironic deployments of N nodes.
To find a provider (by name or UUID), we would iterate over this list,
an O(N) operation. For large ironic deployments, this added up fast -
see the referenced bug.
With this change, we store roots in two dicts: one keyed by UUID, one
keyed by name. To find a provider, we first check these dicts. If the
provider we're looking for is a root, this is now O(1). (If it's a
child, it would still be O(N), because we iterate over all the roots
looking for a descendant that matches. But ironic deployments don't have
child providers (yet?) (right?) so that should be n/a. For non-ironic
deployments it's unchanged: O(M) where M is the number of descendants,
which should be very small for the time being.)
Test note: Existing tests in nova.tests.unit.compute.test_provider_tree
thoroughly cover all the affected code paths. There was one usage of
ProviderTree.roots that was untested and broken (even before this
change) which is now fixed.
Conflicts (rocky backport):
nova/compute/provider_tree.py
The return_root kwarg to _find_with_lock was added in stein.
nova/tests/unit/virt/libvirt/test_driver.py
and
nova/virt/libvirt/driver.py
are n/a because the code iterating over the provider tree roots was
added in stein (for vgpu handling)
Change-Id: Ibf430a8bc2a2af9353b8cdf875f8506377a1c9c2
Closes-Bug: #1816086
(cherry picked from commit 8c797450cbff5194fb6791cd0a07fa060dc8af72)
(cherry picked from commit 754d8eb76c6fcd539fc2c32f0e2f90f6503b9f0c)
Reviewed: https:/ /review. opendev. org/670182 /git.openstack. org/cgit/ openstack/ nova/commit/ ?id=00e5e3a7443 dd3172024449701 3b040729490dcd
Committed: https:/
Submitter: Zuul
Branch: stable/rocky
commit 00e5e3a7443dd31 720244497013b04 0729490dcd
Author: Eric Fried <email address hidden>
Date: Fri Feb 15 10:54:36 2019 -0600
Perf: Use dicts for ProviderTree roots
ProviderTree used to keep track of root providers in a list. Since we
don't yet have sharing providers, this would always be a list of one for
non-ironic deployments, or N for ironic deployments of N nodes.
To find a provider (by name or UUID), we would iterate over this list,
an O(N) operation. For large ironic deployments, this added up fast -
see the referenced bug.
With this change, we store roots in two dicts: one keyed by UUID, one
keyed by name. To find a provider, we first check these dicts. If the
provider we're looking for is a root, this is now O(1). (If it's a
child, it would still be O(N), because we iterate over all the roots
looking for a descendant that matches. But ironic deployments don't have
child providers (yet?) (right?) so that should be n/a. For non-ironic
deployments it's unchanged: O(M) where M is the number of descendants,
which should be very small for the time being.)
Test note: Existing tests in nova.tests. unit.compute. test_provider_ tree e.roots that was untested and broken (even before this
thoroughly cover all the affected code paths. There was one usage of
ProviderTre
change) which is now fixed.
Conflicts (rocky backport): compute/ provider_ tree.py tests/unit/ virt/libvirt/ test_driver. py virt/libvirt/ driver. py
nova/
The return_root kwarg to _find_with_lock was added in stein.
nova/
and
nova/
are n/a because the code iterating over the provider tree roots was
added in stein (for vgpu handling)
Change-Id: Ibf430a8bc2a2af 9353b8cdf875f85 06377a1c9c2 4fb6791cd0a07fa 060dc8af72) 39fc2c32f0e2f90 f6503b9f0c)
Closes-Bug: #1816086
(cherry picked from commit 8c797450cbff519
(cherry picked from commit 754d8eb76c6fcd5