@@ -28,6 +28,7 @@ type updateOptions struct {

 	memorySwap         opts.MemSwapBytes

 	kernelMemory       opts.MemBytes

 	restartPolicy      string

+	cpus               opts.NanoCPUs

 	nFlag int

@@ -66,6 +67,9 @@ func NewUpdateCommand(dockerCli *command.DockerCli) *cobra.Command {

 	flags.Var(&opts.kernelMemory, "kernel-memory", "Kernel memory limit")

 	flags.StringVar(&opts.restartPolicy, "restart", "", "Restart policy to apply when a container exits")

+	flags.Var(&opts.cpus, "cpus", "Number of CPUs")

+	flags.SetAnnotation("cpus", "version", []string{"1.29"})

+

 	return cmd

 }

@@ -97,6 +101,7 @@ func runUpdate(dockerCli *command.DockerCli, opts *updateOptions) error {

 		CPUQuota:           opts.cpuQuota,

 		CPURealtimePeriod:  opts.cpuRealtimePeriod,

 		CPURealtimeRuntime: opts.cpuRealtimeRuntime,

+		NanoCPUs:           opts.cpus.Value(),

 	}

 	updateConfig := containertypes.UpdateConfig{

@@ -286,12 +286,33 @@ func (container *Container) UpdateContainer(hostConfig *containertypes.HostConfi

 	// update resources of container

 	resources := hostConfig.Resources

 	cResources := &container.HostConfig.Resources

+

+	// validate NanoCPUs, CPUPeriod, and CPUQuota

+	// Becuase NanoCPU effectively updates CPUPeriod/CPUQuota,

+	// once NanoCPU is already set, updating CPUPeriod/CPUQuota will be blocked, and vice versa.

+	// In the following we make sure the intended update (resources) does not conflict with the existing (cResource).

+	if resources.NanoCPUs > 0 && cResources.CPUPeriod > 0 {

+		return fmt.Errorf("Conflicting options: Nano CPUs cannot be updated as CPU Period has already been set")

+	}

+	if resources.NanoCPUs > 0 && cResources.CPUQuota > 0 {

+		return fmt.Errorf("Conflicting options: Nano CPUs cannot be updated as CPU Quota has already been set")

+	}

+	if resources.CPUPeriod > 0 && cResources.NanoCPUs > 0 {

+		return fmt.Errorf("Conflicting options: CPU Period cannot be updated as NanoCPUs has already been set")

+	}

+	if resources.CPUQuota > 0 && cResources.NanoCPUs > 0 {

+		return fmt.Errorf("Conflicting options: CPU Quota cannot be updated as NanoCPUs has already been set")

+	}

+

 	if resources.BlkioWeight != 0 {

 		cResources.BlkioWeight = resources.BlkioWeight

 	}

 	if resources.CPUShares != 0 {

 		cResources.CPUShares = resources.CPUShares

 	}

+	if resources.NanoCPUs != 0 {

+		cResources.NanoCPUs = resources.NanoCPUs

+	}

 	if resources.CPUPeriod != 0 {

 		cResources.CPUPeriod = resources.CPUPeriod

 	}

@@ -3,6 +3,8 @@

 package daemon

 import (

+	"time"

+

 	"github.com/docker/docker/api/types/container"

 	"github.com/docker/docker/libcontainerd"

 )

@@ -11,8 +13,13 @@ func toContainerdResources(resources container.Resources) libcontainerd.Resource

 	var r libcontainerd.Resources

 	r.BlkioWeight = uint64(resources.BlkioWeight)

 	r.CpuShares = uint64(resources.CPUShares)

-	r.CpuPeriod = uint64(resources.CPUPeriod)

-	r.CpuQuota = uint64(resources.CPUQuota)

+	if resources.NanoCPUs != 0 {

+		r.CpuPeriod = uint64(100 * time.Millisecond / time.Microsecond)

+		r.CpuQuota = uint64(resources.NanoCPUs) * r.CpuPeriod / 1e9

+	} else {

+		r.CpuPeriod = uint64(resources.CPUPeriod)

+		r.CpuQuota = uint64(resources.CPUQuota)

+	}

 	r.CpusetCpus = resources.CpusetCpus

 	r.CpusetMems = resources.CpusetMems

 	r.MemoryLimit = uint64(resources.Memory)

@@ -39,6 +39,7 @@ keywords: "API, Docker, rcli, REST, documentation"

 * `POST /services/create` and `POST /services/(id or name)/update` now accept a `rollback` value for `FailureAction`.

 * `POST /services/create` and `POST /services/(id or name)/update` now accept an optional `RollbackConfig` object which specifies rollback options.

 * `GET /services` now supports a `mode` filter to filter services based on the service mode (either `global` or `replicated`).

+* `POST /containers/(name)/update` now supports updating `NanoCPUs` that represents CPU quota in units of 10<sup>-9</sup> CPUs.

 ## v1.27 API changes

@@ -21,12 +21,13 @@ Usage:  docker update [OPTIONS] CONTAINER [CONTAINER...]

 Update configuration of one or more containers

 Options:

-      --blkio-weight value          Block IO (relative weight), between 10 and 1000

+      --blkio-weight uint16         Block IO (relative weight), between 10 and 1000, or 0 to disable (default 0)

       --cpu-period int              Limit CPU CFS (Completely Fair Scheduler) period

       --cpu-quota int               Limit CPU CFS (Completely Fair Scheduler) quota

-  -c, --cpu-shares int              CPU shares (relative weight)

       --cpu-rt-period int           Limit the CPU real-time period in microseconds

       --cpu-rt-runtime int          Limit the CPU real-time runtime in microseconds

+  -c, --cpu-shares int              CPU shares (relative weight)

+      --cpus decimal                Number of CPUs (default 0.000)

       --cpuset-cpus string          CPUs in which to allow execution (0-3, 0,1)

       --cpuset-mems string          MEMs in which to allow execution (0-3, 0,1)

       --help                        Print usage

@@ -282,3 +282,38 @@ func (s *DockerSuite) TestUpdateNotAffectMonitorRestartPolicy(c *check.C) {

 	c.Assert(err, checker.IsNil)

 	c.Assert(waitRun(id), checker.IsNil)

 }

+

+func (s *DockerSuite) TestUpdateWithNanoCPUs(c *check.C) {

+	testRequires(c, cpuCfsQuota, cpuCfsPeriod)

+

+	file1 := "/sys/fs/cgroup/cpu/cpu.cfs_quota_us"

+	file2 := "/sys/fs/cgroup/cpu/cpu.cfs_period_us"

+

+	out, _ := dockerCmd(c, "run", "-d", "--cpus", "0.5", "--name", "top", "busybox", "top")

+	c.Assert(strings.TrimSpace(out), checker.Not(checker.Equals), "")

+

+	out, _ = dockerCmd(c, "exec", "top", "sh", "-c", fmt.Sprintf("cat %s && cat %s", file1, file2))

+	c.Assert(strings.TrimSpace(out), checker.Equals, "50000\n100000")

+

+	out = inspectField(c, "top", "HostConfig.NanoCpus")

+	c.Assert(out, checker.Equals, "5e+08", check.Commentf("setting the Nano CPUs failed"))

+	out = inspectField(c, "top", "HostConfig.CpuQuota")

+	c.Assert(out, checker.Equals, "0", check.Commentf("CPU CFS quota should be 0"))

+	out = inspectField(c, "top", "HostConfig.CpuPeriod")

+	c.Assert(out, checker.Equals, "0", check.Commentf("CPU CFS period should be 0"))

+

+	out, _, err := dockerCmdWithError("update", "--cpu-quota", "80000", "top")

+	c.Assert(err, checker.NotNil)

+	c.Assert(out, checker.Contains, "Conflicting options: CPU Quota cannot be updated as NanoCPUs has already been set")

+

+	out, _ = dockerCmd(c, "update", "--cpus", "0.8", "top")

+	out = inspectField(c, "top", "HostConfig.NanoCpus")

+	c.Assert(out, checker.Equals, "8e+08", check.Commentf("updating the Nano CPUs failed"))

+	out = inspectField(c, "top", "HostConfig.CpuQuota")

+	c.Assert(out, checker.Equals, "0", check.Commentf("CPU CFS quota should be 0"))

+	out = inspectField(c, "top", "HostConfig.CpuPeriod")

+	c.Assert(out, checker.Equals, "0", check.Commentf("CPU CFS period should be 0"))

+

+	out, _ = dockerCmd(c, "exec", "top", "sh", "-c", fmt.Sprintf("cat %s && cat %s", file1, file2))

+	c.Assert(strings.TrimSpace(out), checker.Equals, "80000\n100000")

+}