Cg2: Expose OOMGroupKill event/writes

cgroup2/manager.go

@@ -59,11 +59,12 @@ var (
 )
 
 type Event struct {
-	Low     uint64
-	High    uint64
-	Max     uint64
-	OOM     uint64
-	OOMKill uint64
+	Low          uint64
+	High         uint64
+	Max          uint64
+	OOM          uint64
+	OOMKill      uint64
+	OOMGroupKill uint64
 }
 
 // Resources for a cgroups v2 unified hierarchy
@@ -679,11 +680,12 @@ func readMemoryEvents(cgroupPath string) (*stats.MemoryEvents, error) {
 		return nil, nil
 	}
 	return &stats.MemoryEvents{
-		Low:     memoryEvents["low"],
-		High:    memoryEvents["high"],
-		Max:     memoryEvents["max"],
-		Oom:     memoryEvents["oom"],
-		OomKill: memoryEvents["oom_kill"],
+		Low:          memoryEvents["low"],
+		High:         memoryEvents["high"],
+		Max:          memoryEvents["max"],
+		Oom:          memoryEvents["oom"],
+		OomKill:      memoryEvents["oom_kill"],
+		OomGroupKill: memoryEvents["oom_group_kill"],
 	}, nil
 }
 
@@ -837,11 +839,12 @@ func (c *Manager) EventChan() (<-chan Event, <-chan error) {
 			}
 
 			ec <- Event{
-				Low:     out["low"],
-				High:    out["high"],
-				Max:     out["max"],
-				OOM:     out["oom"],
-				OOMKill: out["oom_kill"],
+				Low:          out["low"],
+				High:         out["high"],
+				Max:          out["max"],
+				OOM:          out["oom"],
+				OOMKill:      out["oom_kill"],
+				OOMGroupKill: out["oom_group_kill"],
 			}
 
 			if shouldExit {

cgroup2/memory.go

@@ -17,11 +17,12 @@
 package cgroup2
 
 type Memory struct {
-	Swap *int64
-	Min  *int64
-	Max  *int64
-	Low  *int64
-	High *int64
+	Swap     *int64
+	Min      *int64
+	Max      *int64
+	Low      *int64
+	High     *int64
+	OOMGroup *bool
 }
 
 func (r *Memory) Values() (o []Value) {
@@ -55,5 +56,15 @@ func (r *Memory) Values() (o []Value) {
 			value:    *r.High,
 		})
 	}
+	if r.OOMGroup != nil {
+		var val int64
+		if *r.OOMGroup {
+			val = 1
+		}
+		o = append(o, Value{
+			filename: "memory.oom.group",
+			value:    val,
+		})
+	}
 	return o
 }

cgroup2/stats/metrics.pb.txt

@@ -509,6 +509,13 @@ file {
       type: TYPE_UINT64
       json_name: "oomKill"
     }
+    field {
+      name: "oom_group_kill"
+      number: 6
+      label: LABEL_OPTIONAL
+      type: TYPE_UINT64
+      json_name: "oomGroupKill"
+    }
   }
   message_type {
     name: "RdmaStat"

cgroup2/stats/metrics.proto

@@ -91,6 +91,7 @@ message MemoryEvents {
 	uint64 max = 3;
 	uint64 oom = 4;
 	uint64 oom_kill = 5;
+	uint64 oom_group_kill = 6;
 }
 
 message RdmaStat {