Merge pull request #25461 from coolljt0725/fix_update_mem

Fix update memory without memoryswap

container/container_unix.go

@@ -283,6 +283,11 @@ func (container *Container) UpdateContainer(hostConfig *containertypes.HostConfi
 		cResources.CpusetMems = resources.CpusetMems
 	}
 	if resources.Memory != 0 {
+		// if memory limit smaller than already set memoryswap limit and doesn't
+		// update the memoryswap limit, then error out.
+		if resources.Memory > cResources.MemorySwap && resources.MemorySwap == 0 {
+			return fmt.Errorf("Memory limit should be smaller than already set memoryswap limit, update the memoryswap at the same time")
+		}
 		cResources.Memory = resources.Memory
 	}
 	if resources.MemorySwap != 0 {

integration-cli/docker_cli_update_unix_test.go

@@ -236,3 +236,17 @@ func (s *DockerSuite) TestUpdateStats(c *check.C) {
 	c.Assert(preMemLimit, checker.Equals, curMemLimit)
 
 }
+
+func (s *DockerSuite) TestUpdateMemoryWithSwapMemory(c *check.C) {
+	testRequires(c, DaemonIsLinux)
+	testRequires(c, memoryLimitSupport)
+	testRequires(c, swapMemorySupport)
+
+	name := "test-update-container"
+	dockerCmd(c, "run", "-d", "--name", name, "--memory", "300M", "busybox", "top")
+	out, _, err := dockerCmdWithError("update", "--memory", "800M", name)
+	c.Assert(err, checker.NotNil)
+	c.Assert(out, checker.Contains, "Memory limit should be smaller than already set memoryswap limit")
+
+	dockerCmd(c, "update", "--memory", "800M", "--memory-swap", "1000M", name)
+}

man/docker-update.1.md

@@ -67,6 +67,12 @@ a running container with kernel memory initialized.
 **-m**, **--memory**=""
    Memory limit (format: <number><optional unit>, where unit = b, k, m or g)
 
+   Note that the memory should be smaller than the already set swap memory limit.
+   If you want update a memory limit bigger than the already set swap memory limit,
+   you should update swap memory limit at the same time. If you don't set swap memory 
+   limit on docker create/run but only memory limit, the swap memory is double
+   the memory limit.
+
 **--memory-reservation**=""
    Memory soft limit (format: <number>[<unit>], where unit = b, k, m or g)