add blkio.weight support

We can use this to control block IO weight of a container.

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

daemon/container.go

@@ -383,6 +383,7 @@ func populateCommand(c *Container, env []string) error {
 		CpusetCpus:     c.hostConfig.CpusetCpus,
 		CpusetMems:     c.hostConfig.CpusetMems,
 		CpuQuota:       c.hostConfig.CpuQuota,
+		BlkioWeight:    c.hostConfig.BlkioWeight,
 		Rlimits:        rlimits,
 		OomKillDisable: c.hostConfig.OomKillDisable,
 	}

daemon/daemon.go

@@ -1184,6 +1184,9 @@ func (daemon *Daemon) verifyHostConfig(hostConfig *runconfig.HostConfig) ([]stri
 		warnings = append(warnings, "Your kernel does not support CPU cfs quota. Quota discarded.")
 		hostConfig.CpuQuota = 0
 	}
+	if hostConfig.BlkioWeight > 0 && (hostConfig.BlkioWeight < 10 || hostConfig.BlkioWeight > 1000) {
+		return warnings, fmt.Errorf("Range of blkio weight is from 10 to 1000.")
+	}
 
 	return warnings, nil
 }

daemon/execdriver/driver.go

@@ -106,6 +106,7 @@ type Resources struct {
 	CpusetCpus     string           `json:"cpuset_cpus"`
 	CpusetMems     string           `json:"cpuset_mems"`
 	CpuQuota       int64            `json:"cpu_quota"`
+	BlkioWeight    int64            `json:"blkio_weight"`
 	Rlimits        []*ulimit.Rlimit `json:"rlimits"`
 	OomKillDisable bool             `json:"oom_kill_disable"`
 }

daemon/execdriver/driver_linux.go

@@ -54,6 +54,7 @@ func SetupCgroups(container *configs.Config, c *Command) error {
 		container.Cgroups.CpusetCpus = c.Resources.CpusetCpus
 		container.Cgroups.CpusetMems = c.Resources.CpusetMems
 		container.Cgroups.CpuQuota = c.Resources.CpuQuota
+		container.Cgroups.BlkioWeight = c.Resources.BlkioWeight
 		container.Cgroups.OomKillDisable = c.Resources.OomKillDisable
 	}
 

daemon/execdriver/lxc/lxc_template.go

@@ -118,6 +118,9 @@ lxc.cgroup.cpuset.mems = {{.Resources.CpusetMems}}
 {{if .Resources.CpuQuota}}
 lxc.cgroup.cpu.cfs_quota_us = {{.Resources.CpuQuota}}
 {{end}}
+{{if .Resources.BlkioWeight}}
+lxc.cgroup.blkio.weight = {{.Resources.BlkioWeight}}
+{{end}}
 {{if .Resources.OomKillDisable}}
 lxc.cgroup.memory.oom_control = {{.Resources.OomKillDisable}}
 {{end}}

docs/man/docker-create.1.md

@@ -8,6 +8,7 @@ docker-create - Create a new container
 **docker create**
 [**-a**|**--attach**[=*[]*]]
 [**--add-host**[=*[]*]]
+[**--blkio-weight**[=*[BLKIO-WEIGHT]*]]
 [**-c**|**--cpu-shares**[=*0*]]
 [**--cap-add**[=*[]*]]
 [**--cap-drop**[=*[]*]]
@@ -59,6 +60,9 @@ IMAGE [COMMAND] [ARG...]
 **--add-host**=[]
    Add a custom host-to-IP mapping (host:ip)
 
+**--blkio-weight**=0
+   Block IO weight (relative weight) accepts a weight value between 10 and 1000.
+
 **-c**, **--cpu-shares**=0
    CPU shares (relative weight)
 

docs/man/docker-run.1.md

@@ -8,6 +8,7 @@ docker-run - Run a command in a new container
 **docker run**
 [**-a**|**--attach**[=*[]*]]
 [**--add-host**[=*[]*]]
+[**--blkio-weight**[=*[BLKIO-WEIGHT]*]]
 [**-c**|**--cpu-shares**[=*0*]]
 [**--cap-add**[=*[]*]]
 [**--cap-drop**[=*[]*]]
@@ -86,6 +87,9 @@ each of stdin, stdout, and stderr.
    Add a line to /etc/hosts. The format is hostname:ip.  The **--add-host**
 option can be set multiple times.
 
+**--blkio-weight**=0
+   Block IO weight (relative weight) accepts a weight value between 10 and 1000.
+
 **-c**, **--cpu-shares**=0
    CPU shares (relative weight)
 

docs/sources/reference/api/docker_remote_api_v1.19.md

@@ -149,6 +149,7 @@ Create a container
                "CpuShares": 512,
                "CpusetCpus": "0,1",
                "CpusetMems": "0,1",
+               "BlkioWeight": 300,
                "OomKillDisable": false,
                "PortBindings": { "22/tcp": [{ "HostPort": "11022" }] },
                "PublishAllPorts": false,
@@ -195,6 +196,7 @@ Json Parameters:
 -   **Cpuset** - The same as CpusetCpus, but deprecated, please don't use.
 -   **CpusetCpus** - String value containing the cgroups CpusetCpus to use.
 -   **CpusetMems** - Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
+-   **BlkioWeight** - Block IO weight (relative weight) accepts a weight value between 10 and 1000.
 -   **OomKillDisable** - Boolean value, whether to disable OOM Killer for the container or not.
 -   **AttachStdin** - Boolean value, attaches to stdin.
 -   **AttachStdout** - Boolean value, attaches to stdout.
@@ -341,6 +343,7 @@ Return low-level information on the container `id`
 		"ExecIDs": null,
 		"HostConfig": {
 			"Binds": null,
+			"BlkioWeight": 0,
 			"CapAdd": null,
 			"CapDrop": null,
 			"ContainerIDFile": "",

docs/sources/reference/commandline/cli.md

@@ -941,6 +941,7 @@ Creates a new container.
 
       -a, --attach=[]            Attach to STDIN, STDOUT or STDERR
       --add-host=[]              Add a custom host-to-IP mapping (host:ip)
+      --blkio-weight=0           Block IO weight (relative weight)
       -c, --cpu-shares=0         CPU shares (relative weight)
       --cap-add=[]               Add Linux capabilities
       --cap-drop=[]              Drop Linux capabilities
@@ -1898,6 +1899,7 @@ To remove an image using its digest:
 
       -a, --attach=[]            Attach to STDIN, STDOUT or STDERR
       --add-host=[]              Add a custom host-to-IP mapping (host:ip)
+      --blkio-weight=0           Block IO weight (relative weight)
       -c, --cpu-shares=0         CPU shares (relative weight)
       --cap-add=[]               Add Linux capabilities
       --cap-drop=[]              Drop Linux capabilities

docs/sources/reference/run.md

@@ -483,6 +483,7 @@ container:
     --cpuset-cpus="": CPUs in which to allow execution (0-3, 0,1)
     --cpuset-mems="": Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
     --cpu-quota=0: Limit the CPU CFS (Completely Fair Scheduler) quota
+    --blkio-weight=0: Block IO weight (relative weight) accepts a weight value between 10 and 1000.
     --oom-kill-disable=true|false: Whether to disable OOM Killer for the container or not.
 
 ### Memory constraints
@@ -654,6 +655,30 @@ Linux Scheduler used by the kernel. Set this value to 50000 to limit the contain
 to 50% of a CPU resource. For multiple CPUs, adjust the `--cpu-quota` as necessary.
 For more information, see the [CFS documentation on bandwidth limiting](https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt).
 
+### Block IO bandwidth (Blkio) constraint
+
+By default, all containers get the same proportion of block IO bandwidth
+(blkio). This proportion is 500. To modify this proportion, change the
+container's blkio weight relative to the weighting of all other running
+containers using the `--blkio-weight` flag.
+
+The `--blkio-weight` flag can set the weighting to a value between 10 to 1000.
+For example, the commands below create two containers with different blkio
+weight:
+
+    $ docker run -ti --name c1 --blkio-weight 300 ubuntu:14.04 /bin/bash
+    $ docker run -ti --name c2 --blkio-weight 600 ubuntu:14.04 /bin/bash
+
+If you do block IO in the two containers at the same time, by, for example:
+
+    $ time dd if=/mnt/zerofile of=test.out bs=1M count=1024 oflag=direct
+
+You'll find that the proportion of time is the same as the proportion of blkio
+weights of the two containers.
+
+> **Note:** The blkio weight setting is only available for direct IO. Buffered IO
+> is not currently supported.
+
 ## Runtime privilege, Linux capabilities, and LXC configuration
 
     --cap-add: Add Linux capabilities

integration-cli/docker_cli_run_test.go

@@ -1158,6 +1158,20 @@ func (s *DockerSuite) TestRunWithCpusetMems(c *check.C) {
 	}
 }
 
+func (s *DockerSuite) TestRunWithBlkioWeight(c *check.C) {
+	cmd := exec.Command(dockerBinary, "run", "--blkio-weight", "300", "busybox", "true")
+	if code, err := runCommand(cmd); err != nil || code != 0 {
+		c.Fatalf("container should run successfully with blkio-weight of 300: %s", err)
+	}
+}
+
+func (s *DockerSuite) TestRunWithBlkioInvalidWeight(c *check.C) {
+	cmd := exec.Command(dockerBinary, "run", "--blkio-weight", "5", "busybox", "true")
+	if _, err := runCommand(cmd); err == nil {
+		c.Fatalf("run with invalid blkio-weight should failed")
+	}
+}
+
 func (s *DockerSuite) TestRunDeviceNumbers(c *check.C) {
 	cmd := exec.Command(dockerBinary, "run", "busybox", "sh", "-c", "ls -l /dev/null")
 	out, _, err := runCommandWithOutput(cmd)

runconfig/hostconfig.go

@@ -168,7 +168,8 @@ type HostConfig struct {
 	CpusetCpus      string // CpusetCpus 0-2, 0,1
 	CpusetMems      string // CpusetMems 0-2, 0,1
 	CpuQuota        int64
-	OomKillDisable  bool // Whether to disable OOM Killer or not
+	BlkioWeight     int64 // Block IO weight (relative weight vs. other containers)
+	OomKillDisable  bool  // Whether to disable OOM Killer or not
 	Privileged      bool
 	PortBindings    nat.PortMap
 	Links           []string

runconfig/parse.go

@@ -65,6 +65,7 @@ func Parse(cmd *flag.FlagSet, args []string) (*Config, *HostConfig, *flag.FlagSe
 		flCpusetCpus      = cmd.String([]string{"#-cpuset", "-cpuset-cpus"}, "", "CPUs in which to allow execution (0-3, 0,1)")
 		flCpusetMems      = cmd.String([]string{"-cpuset-mems"}, "", "MEMs in which to allow execution (0-3, 0,1)")
 		flCpuQuota        = cmd.Int64([]string{"-cpu-quota"}, 0, "Limit the CPU CFS quota")
+		flBlkioWeight     = cmd.Int64([]string{"-blkio-weight"}, 0, "Block IO (relative weight), between 10 and 1000")
 		flNetMode         = cmd.String([]string{"-net"}, "bridge", "Set the Network mode for the container")
 		flMacAddress      = cmd.String([]string{"-mac-address"}, "", "Container MAC address (e.g. 92:d0:c6:0a:29:33)")
 		flIpcMode         = cmd.String([]string{"-ipc"}, "", "IPC namespace to use")
@@ -308,6 +309,7 @@ func Parse(cmd *flag.FlagSet, args []string) (*Config, *HostConfig, *flag.FlagSe
 		CpusetCpus:      *flCpusetCpus,
 		CpusetMems:      *flCpusetMems,
 		CpuQuota:        *flCpuQuota,
+		BlkioWeight:     *flBlkioWeight,
 		OomKillDisable:  *flOomKillDisable,
 		Privileged:      *flPrivileged,
 		PortBindings:    portBindings,