Add support for kernel memory limit

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

integration-cli/docker_cli_run_unix_test.go

@@ -283,6 +283,18 @@ func (s *DockerSuite) TestRunWithCpuPeriod(c *check.C) {
 	}
 }
 
+func (s *DockerSuite) TestRunWithKernelMemory(c *check.C) {
+	testRequires(c, kernelMemorySupport)
+
+	dockerCmd(c, "run", "--kernel-memory", "50M", "--name", "test", "busybox", "true")
+
+	out, err := inspectField("test", "HostConfig.KernelMemory")
+	c.Assert(err, check.IsNil)
+	if out != "52428800" {
+		c.Fatalf("setting the kernel memory limit failed")
+	}
+}
+
 func (s *DockerSuite) TestRunOOMExitCode(c *check.C) {
 	testRequires(c, oomControl)
 	errChan := make(chan error)

integration-cli/requirements_unix.go

@@ -54,4 +54,17 @@ var (
 		},
 		"Test requires Oom control enabled.",
 	}
+	kernelMemorySupport = testRequirement{
+		func() bool {
+			cgroupMemoryMountpoint, err := cgroups.FindCgroupMountpoint("memory")
+			if err != nil {
+				return false
+			}
+			if _, err := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.kmem.limit_in_bytes")); err != nil {
+				return false
+			}
+			return true
+		},
+		"Test requires an environment that supports cgroup kernel memory.",
+	}
 )