cpuallocator: allow querying CPU priorities.

Allow querying cpusets for all discovered priorities. This is
useful and necessary for policies which pass pre-filtered CPU
sets to the allocator, to ensure that pre-filtering and the
allocator logic has a mutual understanding of which CPU cores
belong to what priority class.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

pkg/cpuallocator/allocator.go

@@ -65,6 +65,7 @@ type allocatorHelper struct {
 type CPUAllocator interface {
 	AllocateCpus(from *cpuset.CPUSet, cnt int, prefer CPUPriority) (cpuset.CPUSet, error)
 	ReleaseCpus(from *cpuset.CPUSet, cnt int, prefer CPUPriority) (cpuset.CPUSet, error)
+	GetCPUPriorities() map[CPUPriority]cpuset.CPUSet
 }
 
 type CPUPriority int
@@ -670,6 +671,16 @@ func (ca *cpuAllocator) ReleaseCpus(from *cpuset.CPUSet, cnt int, prefer CPUPrio
 	return result, err
 }
 
+// GetCPUPriorities returns the CPUSets for the discovered priorities.
+func (ca *cpuAllocator) GetCPUPriorities() map[CPUPriority]cpuset.CPUSet {
+	prios := make(map[CPUPriority]cpuset.CPUSet)
+	for prio := CPUPriority(0); prio < NumCPUPriorities; prio++ {
+		cset := ca.topologyCache.cpuPriorities[prio]
+		prios[prio] = cset.Clone()
+	}
+	return prios
+}
+
 func newTopologyCache(sys sysfs.System) topologyCache {
 	c := topologyCache{
 		pkg:  make(map[idset.ID]cpuset.CPUSet),