topology,sysfs: implement partial hint resolution.

Add functions for resolving partial, NUMA-only topology hints to fully defined CPU-specific ones using a sysfs instance. Signed-off-by: Krisztian Litkey <[email protected]>
containers · Nov 30, 2024 · 36f72ed · 36f72ed
1 parent a8e482d
commit 36f72ed
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diff --git a/pkg/sysfs/system.go b/pkg/sysfs/system.go
@@ -123,6 +123,8 @@ type System interface {
 
 	Offlined() cpuset.CPUSet
 	Isolated() cpuset.CPUSet
+
+	NodeHintToCPUs(string) string
 }
 
 // System devices
@@ -742,6 +744,24 @@ func (sys *system) Isolated() cpuset.CPUSet {
 	return sys.IsolatedCPUs()
 }
 
+// Resolve given node topology hints to CPUs.
+func (sys *system) NodeHintToCPUs(nodes string) string {
+	mset, err := cpuset.Parse(nodes)
+	if err != nil {
+		log.Error("failed to resolve nodes %q to CPUs: %v", nodes, err)
+		return ""
+	}
+
+	cset := cpuset.New()
+	for _, id := range mset.List() {
+		if n, ok := sys.nodes[id]; ok {
+			cset = cset.Union(n.CPUSet())
+		}
+	}
+
+	return cset.Intersection(sys.OnlineCPUs()).String()
+}
+
 // Discover Cpus present in the system.
 func (sys *system) discoverCPUs() error {
 	if sys.cpus != nil {

diff --git a/pkg/topology/topology.go b/pkg/topology/topology.go
@@ -227,6 +227,17 @@ func MergeTopologyHints(org, hints Hints) (res Hints) {
 	return
 }
 
+// ResolvePartialHints resolves NUMA-only hints to CPU hints using the given function.
+func (hints Hints) ResolvePartialHints(resolve func(NUMAs string) string) {
+	for k, h := range hints {
+		if h.CPUs == "" && h.NUMAs != "" {
+			h.CPUs = resolve(h.NUMAs)
+			log.Debugf("partial NUMA hint %q resolved to CPUs %q", h.NUMAs, h.CPUs)
+			hints[k] = h
+		}
+	}
+}
+
 // String returns the hints as a string.
 func (h *Hint) String() string {
 	cpus, nodes, sockets, sep := "", "", "", ""