cache: support annotations to preserve CPU and memory pinning

Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>

pkg/resmgr/cache/cache.go

@@ -59,6 +59,11 @@ const (
 
 	// TopologyHintsKey can be used to opt out from automatic topology hint generation.
 	TopologyHintsKey = "topologyhints" + "." + kubernetes.ResmgrKeyNamespace
+
+	// PreserveCpuKey means that CPU resources should not be touched.
+	PreserveCpuKey = "cpu.preserve." + kubernetes.ResmgrKeyNamespace
+	// PreserveMemoryKey means that memory resources should not be touched.
+	PreserveMemoryKey = "memory.preserve." + kubernetes.ResmgrKeyNamespace
 )
 
 // PodState is the pod state in the runtime.
@@ -245,6 +250,13 @@ type Container interface {
 	// GetMemorySwap gets the swap limit in bytes for the container.
 	GetMemorySwap() int64
 
+	// PreserveCpuResources() returns true if CPU resources of the
+	// container must not be changed.
+	PreserveCpuResources() bool
+	// PreserveMemoryResources() returns true if memory resources
+	// of the container must not be changed.
+	PreserveMemoryResources() bool
+
 	// GetPendingAdjusmentn clears and returns any pending adjustment for the container.
 	GetPendingAdjustment() *nri.ContainerAdjustment
 	// GetPendingUpdate clears and returns any pending update for the container.

pkg/resmgr/cache/container.go

@@ -761,6 +761,16 @@ func (c *container) GetMemorySwap() int64 {
 	return c.Ctr.GetLinux().GetResources().GetMemory().GetSwap().GetValue()
 }
 
+func (c *container) PreserveCpuResources() bool {
+	value, ok := c.GetEffectiveAnnotation(PreserveCpuKey)
+	return ok && value == "true"
+}
+
+func (c *container) PreserveMemoryResources() bool {
+	value, ok := c.GetEffectiveAnnotation(PreserveMemoryKey)
+	return ok && value == "true"
+}
+
 var (
 	// More complext rules, for Kubelet secrets and config maps
 	ignoredTopologyPathRegexps = []*regexp.Regexp{