Separating cgroup Memory and MemoryReservation.

This will allow for these to be set independently. Keep the current Docker behavior where Memory and MemoryReservation are set to the value of Memory.

Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)

daemon/execdriver/native/configuration/parse.go

@@ -21,10 +21,11 @@ var actions = map[string]Action{
 
 	"net.join": joinNetNamespace, // join another containers net namespace
 
-	"cgroups.cpu_shares":  cpuShares,  // set the cpu shares
-	"cgroups.memory":      memory,     // set the memory limit
-	"cgroups.memory_swap": memorySwap, // set the memory swap limit
-	"cgroups.cpuset.cpus": cpusetCpus, // set the cpus used
+	"cgroups.cpu_shares":         cpuShares,         // set the cpu shares
+	"cgroups.memory":             memory,            // set the memory limit
+	"cgroups.memory_reservation": memoryReservation, // set the memory reservation
+	"cgroups.memory_swap":        memorySwap,        // set the memory swap limit
+	"cgroups.cpuset.cpus":        cpusetCpus,        // set the cpus used
 
 	"apparmor_profile": apparmorProfile, // set the apparmor profile to apply
 
@@ -70,6 +71,19 @@ func memory(container *libcontainer.Container, context interface{}, value string
 	return nil
 }
 
+func memoryReservation(container *libcontainer.Container, context interface{}, value string) error {
+	if container.Cgroups == nil {
+		return fmt.Errorf("cannot set cgroups when they are disabled")
+	}
+
+	v, err := utils.RAMInBytes(value)
+	if err != nil {
+		return err
+	}
+	container.Cgroups.MemoryReservation = v
+	return nil
+}
+
 func memorySwap(container *libcontainer.Container, context interface{}, value string) error {
 	if container.Cgroups == nil {
 		return fmt.Errorf("cannot set cgroups when they are disabled")

daemon/execdriver/native/configuration/parse_test.go

@@ -93,7 +93,7 @@ func TestCpuShares(t *testing.T) {
 	}
 }
 
-func TestCgroupMemory(t *testing.T) {
+func TestMemory(t *testing.T) {
 	var (
 		container = template.New()
 		opts      = []string{
@@ -109,6 +109,22 @@ func TestCgroupMemory(t *testing.T) {
 	}
 }
 
+func TestMemoryReservation(t *testing.T) {
+	var (
+		container = template.New()
+		opts      = []string{
+			"cgroups.memory_reservation=500m",
+		}
+	)
+	if err := ParseConfiguration(container, nil, opts); err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := int64(500 * 1024 * 1024); container.Cgroups.MemoryReservation != expected {
+		t.Fatalf("expected memory reservation %d got %d", expected, container.Cgroups.MemoryReservation)
+	}
+}
+
 func TestAddCap(t *testing.T) {
 	var (
 		container = template.New()

daemon/execdriver/native/create.go

@@ -91,6 +91,7 @@ func (d *driver) setupCgroups(container *libcontainer.Container, c *execdriver.C
 	if c.Resources != nil {
 		container.Cgroups.CpuShares = c.Resources.CpuShares
 		container.Cgroups.Memory = c.Resources.Memory
+		container.Cgroups.MemoryReservation = c.Resources.Memory
 		container.Cgroups.MemorySwap = c.Resources.MemorySwap
 	}
 	return nil