Merge pull request #4462 from omame/omame/cpu_cfs_period

Add support for specifying cpu_cfs_period in the Docker driver

client/driver/docker.go

@@ -235,6 +235,7 @@ type DockerDriverConfig struct {
 	ReadonlyRootfs       bool                `mapstructure:"readonly_rootfs"`        // Mount the container’s root filesystem as read only
 	AdvertiseIPv6Address bool                `mapstructure:"advertise_ipv6_address"` // Flag to use the GlobalIPv6Address from the container as the detected IP
 	CPUHardLimit         bool                `mapstructure:"cpu_hard_limit"`         // Enforce CPU hard limit.
+	CPUCFSPeriod         int64               `mapstructure:"cpu_cfs_period"`         // Set the period for the CFS scheduler for the cgroup.
 	PidsLimit            int64               `mapstructure:"pids_limit"`             // Enforce Docker Pids limit
 }
 
@@ -741,6 +742,9 @@ func (d *DockerDriver) Validate(config map[string]interface{}) error {
 			"cpu_hard_limit": {
 				Type: fields.TypeBool,
 			},
+			"cpu_cfs_period": {
+				Type: fields.TypeInt,
+			},
 			"pids_limit": {
 				Type: fields.TypeInt,
 			},
@@ -1238,7 +1242,14 @@ func (d *DockerDriver) createContainerConfig(ctx *ExecContext, task *structs.Tas
 	if driverConfig.CPUHardLimit {
 		numCores := runtime.NumCPU()
 		percentTicks := float64(task.Resources.CPU) / float64(d.node.Resources.CPU)
-		hostConfig.CPUQuota = int64(percentTicks*defaultCFSPeriodUS) * int64(numCores)
+		if driverConfig.CPUCFSPeriod < 0 || driverConfig.CPUCFSPeriod > 1000000 {
+			return c, fmt.Errorf("invalid value for cpu_cfs_period")
+		}
+		if driverConfig.CPUCFSPeriod == 0 {
+			driverConfig.CPUCFSPeriod = defaultCFSPeriodUS
+		}
+		hostConfig.CPUPeriod = driverConfig.CPUCFSPeriod
+		hostConfig.CPUQuota = int64(percentTicks*float64(driverConfig.CPUCFSPeriod)) * int64(numCores)
 	}
 
 	// Windows does not support MemorySwap/MemorySwappiness #2193

client/driver/docker_test.go

@@ -2524,3 +2524,25 @@ func TestDockerImageRef(t *testing.T) {
 		})
 	}
 }
+
+func TestDockerDriver_CPUCFSPeriod(t *testing.T) {
+	if !tu.IsTravis() {
+		t.Parallel()
+	}
+	if !testutil.DockerIsConnected(t) {
+		t.Skip("Docker not connected")
+	}
+
+	task, _, _ := dockerTask(t)
+	task.Config["cpu_hard_limit"] = true
+	task.Config["cpu_cfs_period"] = 1000000
+
+	client, handle, cleanup := dockerSetup(t, task)
+	defer cleanup()
+
+	waitForExist(t, client, handle)
+
+	container, err := client.InspectContainer(handle.ContainerID())
+	assert.Nil(t, err, "Error inspecting container: %v", err)
+	assert.Equal(t, int64(1000000), container.HostConfig.CPUPeriod, "cpu_cfs_period option incorrectly set")
+}

website/source/docs/drivers/docker.html.md

@@ -361,6 +361,11 @@ The `docker` driver supports the following configuration in the job spec.  Only
   soft limiting is used and containers are able to burst above their CPU limit
   when there is idle capacity.
 
+* `cpu_cfs_period` - (Optional) An integer value that specifies the duration in microseconds of the period
+  during which the CPU usage quota is measured. The default is 100000 (0.1 second) and the maximum allowed
+  value is 1000000 (1 second). See [here](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/resource_management_guide/sec-cpu#sect-cfs)
+  for more details.
+
 * `advertise_ipv6_address` - (Optional) `true` or `false` (default). Use the container's
    IPv6 address (GlobalIPv6Address in Docker) when registering services and checks.
    See [IPv6 Docker containers](/docs/job-specification/service.html#IPv6 Docker containers) for details.