Fix failure setting OOM score adjustment

When OOM score adjustment needs to be set, all the containers need to be
loaded to find all containers that belong to the sandbox. However, each
load signals the container to ensure it is still alive. OOM score
adjustment is set during creation and deletion of every container, generating
a flood of signals to all containers. The fix removes the signal check
when it's not needed.

There is also a race fetching OOM score adjustment value from the parent when
the sandbox exits at the same  time (the time it took to signal containers above
made this window quite large). The fix is to store the original value
in the sandbox state file and use it when the value needs to be restored.

Also add more logging and made the existing ones more consistent to help with
debugging.

PiperOrigin-RevId: 340940799

1 files changed, 11 insertions, 2 deletions

diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go
index c4309feb3..4a4110477 100644
--- a/runsc/sandbox/sandbox.go
+++ b/runsc/sandbox/sandbox.go
@@ -66,6 +66,10 @@ type Sandbox struct {
 	// Cgroup has the cgroup configuration for the sandbox.
 	Cgroup *cgroup.Cgroup `json:"cgroup"`
 
+	// OriginalOOMScoreAdj stores the value of oom_score_adj when the sandbox
+	// started, before it may be modified.
+	OriginalOOMScoreAdj int `json:"originalOomScoreAdj"`
+
 	// child is set if a sandbox process is a child of the current process.
 	//
 	// This field isn't saved to json, because only a creator of sandbox
@@ -739,6 +743,11 @@ func (s *Sandbox) createSandboxProcess(conf *config.Config, args *Args, startSyn
 		}
 		return err
 	}
+	s.OriginalOOMScoreAdj, err = specutils.GetOOMScoreAdj(cmd.Process.Pid)
+	if err != nil {
+		return err
+	}
+
 	s.child = true
 	s.Pid = cmd.Process.Pid
 	log.Infof("Sandbox started, PID: %d", s.Pid)
@@ -1133,11 +1142,11 @@ func (s *Sandbox) DestroyContainer(cid string) error {
 
 func (s *Sandbox) destroyContainer(cid string) error {
 	if s.IsRootContainer(cid) {
-		log.Debugf("Destroying root container %q by destroying sandbox", cid)
+		log.Debugf("Destroying root container by destroying sandbox, cid: %s", cid)
 		return s.destroy()
 	}
 
-	log.Debugf("Destroying container %q in sandbox %q", cid, s.ID)
+	log.Debugf("Destroying container, cid: %s, sandbox: %s", cid, s.ID)
 	conn, err := s.sandboxConnect()
 	if err != nil {
 		return err