This patch fixes an issue in the TopologyManager that wouldn't allow
pods to be admitted if pods were launched with the SingleNUMANode policy
and any of the hint providers had no NUMA preferences.
This is due to 2 factors:
1) Any hint provider that passes back a `nil` as its hints, has its hint
automatically transformed into a single {11 true} hint before merging
2) We added a special casing for the SingleNumaNodePolicy() in the
TopologyManager that essentially turns these hints into a
{11 false} anytime a {11 true} is seen.
The current patch reworks this logic so the that TopologyManager can
tell the difference between a "don't care" hint and a true "{11 true}"
hint returned by the hint provider. Only true "{11 true}" hints will be
converted by the special casing for the SingleNumaNodePolicy(), while
"don't care" hints will not.
This is a short term fix for this issue until we do a larger refactoring
of this code for the 1.17 release.
- As discussed in reviews and other public channels,
this abstraction is used to represent numa nodes, not sockets.
- There is nothing inherently related to sockets in this package anyway.
Added one off fix for single-numa-node policy to correctly
reject pod admission on a resource allocation that spans
NUMA nodes
Co-authored-by: Kevin Klues <kklues@nvidia.com>
Previously it only took a bool, which limited the logic it could perform
to determine if a pod should be admitted or not based on the merged hint
from the policy.
As part of this, update the logic to use the NUMA information instead of
the Socket information when generating and consuming TopologyHints in
the CPUManager.
Unfortunately, the NUMA information is not readily available from
cadvisor, so we have to roll the logic to discover it by hand. In the
future, we should remove this custiom code to use the information
provided by cadvisor once it is made available.
At present, there is no way for a hint provider to return distinct hints
for different resource types via a call to GetTopologyHints(). This
means that hint providers that govern multiple resource types (e.g. the
devicemanager) must do some sort of "pre-merge" on the hints it
generates for each resource type before passing them back to the
TopologyManager.
This patch changes the GetTopologyHints() interface to allow a hint
provider to pass back raw hints for each resource type, and allow the
TopologyManager to merge them using a single unified strategy.
This change also allows the TopologyManager to recognize which
resource type a set of hints originated from, should this information
become useful in the future.
