Add support for updating oom_score_adj

rebase

Author: Karthik-K-N

libcontainer/container_linux.go

@@ -171,6 +171,16 @@ func (c *Container) Set(config configs.Config) error {
 	if status == Stopped {
 		return ErrNotRunning
 	}
+
+	// Set the oom_score_adj value
+	if config.OomScoreAdj != nil && *config.OomScoreAdj != 0 {
+		if c.hasInit() {
+			if err := os.WriteFile(fmt.Sprintf("/proc/%d/oom_score_adj", c.initProcess.pid()), []byte(strconv.Itoa(*config.OomScoreAdj)), unix.O_WRONLY); err != nil {
+				return err
+			}
+		}
+	}
+
 	if err := c.cgroupManager.Set(config.Cgroups.Resources); err != nil {
 		// Set configs back
 		if err2 := c.cgroupManager.Set(c.config.Cgroups.Resources); err2 != nil {

update.go

@@ -136,6 +136,10 @@ other options are ignored.
 			Name:  "mem-bw-schema",
 			Usage: "The string of Intel RDT/MBA memory bandwidth schema",
 		},
+		cli.StringFlag{
+			Name:  "oom-score-adj",
+			Usage: "oom score adj value",
+		},
 	},
 	Action: func(context *cli.Context) error {
 		if err := checkArgs(context, 1, exactArgs); err != nil {
@@ -255,6 +259,10 @@ other options are ignored.
 			r.Pids.Limit = int64(context.Int("pids-limit"))
 		}
 
+		if oomScoreAdj := context.Int("oom-score-adj"); oomScoreAdj != 0 {
+			config.OomScoreAdj = &oomScoreAdj
+		}
+
 		// Fix up values
 		if r.Memory.Limit != nil && *r.Memory.Limit == -1 && r.Memory.Swap == nil {
 			// To avoid error "unable to set swap limit without memory limit"