@@ -95,3 +95,7 @@ func (d *driver) Info(id string) execdriver.Info {

 func (d *driver) Name() string {

 	return fmt.Sprintf("%s-%s", DriverName, Version)

 }

+

+func (d *driver) GetPidsForContainer(id string) ([]int, error) {

+	return nil, fmt.Errorf("Not supported")

+}

@@ -60,9 +60,10 @@ type Info interface {

 type Driver interface {

 	Run(c *Command, startCallback StartCallback) (int, error) // Run executes the process and blocks until the process exits and returns the exit code

 	Kill(c *Command, sig int) error

-	Restore(c *Command) error // Wait and try to re-attach on an out of process command

-	Name() string             // Driver name

-	Info(id string) Info      // "temporary" hack (until we move state from core to plugins)

+	Restore(c *Command) error                     // Wait and try to re-attach on an out of process command

+	Name() string                                 // Driver name

+	Info(id string) Info                          // "temporary" hack (until we move state from core to plugins)

+	GetPidsForContainer(id string) ([]int, error) // Returns a list of pids for the given container.

 }

 // Network settings of the container

@@ -3,12 +3,14 @@ package lxc

 import (

 	"fmt"

 	"github.com/dotcloud/docker/execdriver"

+	"github.com/dotcloud/docker/pkg/cgroups"

 	"github.com/dotcloud/docker/utils"

 	"io/ioutil"

 	"log"

 	"os"

 	"os/exec"

 	"path"

+	"path/filepath"

 	"strconv"

 	"strings"

 	"syscall"

@@ -281,6 +283,45 @@ func (d *driver) Info(id string) execdriver.Info {

 	}

 }

+func (d *driver) GetPidsForContainer(id string) ([]int, error) {

+	pids := []int{}

+

+	// memory is chosen randomly, any cgroup used by docker works

+	subsystem := "memory"

+

+	cgroupRoot, err := cgroups.FindCgroupMountpoint(subsystem)

+	if err != nil {

+		return pids, err

+	}

+

+	cgroupDir, err := cgroups.GetThisCgroupDir(subsystem)

+	if err != nil {

+		return pids, err

+	}

+

+	filename := filepath.Join(cgroupRoot, cgroupDir, id, "tasks")

+	if _, err := os.Stat(filename); os.IsNotExist(err) {

+		// With more recent lxc versions use, cgroup will be in lxc/

+		filename = filepath.Join(cgroupRoot, cgroupDir, "lxc", id, "tasks")

+	}

+

+	output, err := ioutil.ReadFile(filename)

+	if err != nil {

+		return pids, err

+	}

+	for _, p := range strings.Split(string(output), "\n") {

+		if len(p) == 0 {

+			continue

+		}

+		pid, err := strconv.Atoi(p)

+		if err != nil {

+			return pids, fmt.Errorf("Invalid pid '%s': %s", p, err)

+		}

+		pids = append(pids, pid)

+	}

+	return pids, nil

+}

+

 func linkLxcStart(root string) error {

 	sourcePath, err := exec.LookPath("lxc-start")

 	if err != nil {

@@ -5,10 +5,7 @@ import (

 	"fmt"

 	"github.com/dotcloud/docker/pkg/mount"

 	"io"

-	"io/ioutil"

 	"os"

-	"path/filepath"

-	"strconv"

 	"strings"

 )

@@ -33,7 +30,7 @@ func FindCgroupMountpoint(subsystem string) (string, error) {

 }

 // Returns the relative path to the cgroup docker is running in.

-func getThisCgroupDir(subsystem string) (string, error) {

+func GetThisCgroupDir(subsystem string) (string, error) {

 	f, err := os.Open("/proc/self/cgroup")

 	if err != nil {

 		return "", err

@@ -58,43 +55,3 @@ func parseCgroupFile(subsystem string, r io.Reader) (string, error) {

 	}

 	return "", fmt.Errorf("cgroup '%s' not found in /proc/self/cgroup", subsystem)

 }

-

-// Returns a list of pids for the given container.

-func GetPidsForContainer(id string) ([]int, error) {

-	pids := []int{}

-

-	// memory is chosen randomly, any cgroup used by docker works

-	subsystem := "memory"

-

-	cgroupRoot, err := FindCgroupMountpoint(subsystem)

-	if err != nil {

-		return pids, err

-	}

-

-	cgroupDir, err := getThisCgroupDir(subsystem)

-	if err != nil {

-		return pids, err

-	}

-

-	filename := filepath.Join(cgroupRoot, cgroupDir, id, "tasks")

-	if _, err := os.Stat(filename); os.IsNotExist(err) {

-		// With more recent lxc versions use, cgroup will be in lxc/

-		filename = filepath.Join(cgroupRoot, cgroupDir, "lxc", id, "tasks")

-	}

-

-	output, err := ioutil.ReadFile(filename)

-	if err != nil {

-		return pids, err

-	}

-	for _, p := range strings.Split(string(output), "\n") {

-		if len(p) == 0 {

-			continue

-		}

-		pid, err := strconv.Atoi(p)

-		if err != nil {

-			return pids, fmt.Errorf("Invalid pid '%s': %s", p, err)

-		}

-		pids = append(pids, pid)

-	}

-	return pids, nil

-}

@@ -7,7 +7,6 @@ import (

 	"github.com/dotcloud/docker/archive"

 	"github.com/dotcloud/docker/auth"

 	"github.com/dotcloud/docker/engine"

-	"github.com/dotcloud/docker/pkg/cgroups"

 	"github.com/dotcloud/docker/pkg/graphdb"

 	"github.com/dotcloud/docker/pkg/systemd"

 	"github.com/dotcloud/docker/registry"

@@ -976,7 +975,7 @@ func (srv *Server) ContainerTop(job *engine.Job) engine.Status {

 			job.Errorf("Container %s is not running", name)

 			return engine.StatusErr

 		}

-		pids, err := cgroups.GetPidsForContainer(container.ID)

+		pids, err := srv.runtime.execDriver.GetPidsForContainer(container.ID)

 		if err != nil {

 			job.Error(err)

 			return engine.StatusErr