4 files changed, 172 insertions, 0 deletions
diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 60b532798..b0282604a 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -114,6 +114,13 @@ const (
 	FsCat = "Fs.Cat"
 )
 
+// Usage related commands (see usage.go for more details).
+const (
+	UsageCollect = "Usage.Collect"
+	UsageUsageFD = "Usage.UsageFD"
+	UsageReduce  = "Usage.Reduce"
+)
+
 // ControlSocketAddr generates an abstract unix socket name for the given ID.
 func ControlSocketAddr(id string) string {
 	return fmt.Sprintf("\x00runsc-sandbox.%s", id)
@@ -157,6 +164,7 @@ func newController(fd int, l *Loader) (*controller, error) {
 	ctrl.srv.Register(&control.Logging{})
 	ctrl.srv.Register(&control.Lifecycle{l.k})
 	ctrl.srv.Register(&control.Fs{l.k})
+	ctrl.srv.Register(&control.Usage{l.k})
 
 	if l.root.conf.ProfileEnable {
 		ctrl.srv.Register(control.NewProfile(l.k))
diff --git a/runsc/cmd/usage.go b/runsc/cmd/usage.go
new file mode 100644
index 000000000..d2aeafa28
--- /dev/null
+++ b/runsc/cmd/usage.go
@@ -0,0 +1,93 @@
+// Copyright 2021 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/google/subcommands"
+	"gvisor.dev/gvisor/runsc/config"
+	"gvisor.dev/gvisor/runsc/container"
+	"gvisor.dev/gvisor/runsc/flag"
+)
+
+// Usage implements subcommands.Command for the "usage" command.
+type Usage struct {
+	full bool
+	fd   bool
+}
+
+// Name implements subcommands.Command.Name.
+func (*Usage) Name() string {
+	return "usage"
+}
+
+// Synopsis implements subcommands.Command.Synopsis.
+func (*Usage) Synopsis() string {
+	return "Usage shows application memory usage across various categories in bytes."
+}
+
+// Usage implements subcommands.Command.Usage.
+func (*Usage) Usage() string {
+	return `usage [flags] <container id> - print memory usages to standard output.`
+}
+
+// SetFlags implements subcommands.Command.SetFlags.
+func (u *Usage) SetFlags(f *flag.FlagSet) {
+	f.BoolVar(&u.full, "full", false, "enumerate all usage by categories")
+	f.BoolVar(&u.fd, "fd", false, "retrieves a subset of usage through the established usage FD")
+}
+
+// Execute implements subcommands.Command.Execute.
+func (u *Usage) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	if f.NArg() < 1 {
+		f.Usage()
+		return subcommands.ExitUsageError
+	}
+
+	id := f.Arg(0)
+	conf := args[0].(*config.Config)
+
+	cont, err := container.Load(conf.RootDir, container.FullID{ContainerID: id}, container.LoadOpts{})
+	if err != nil {
+		Fatalf("loading container: %v", err)
+	}
+
+	if !u.fd {
+		m, err := cont.Usage(u.full)
+		if err != nil {
+			Fatalf("usage failed: %v", err)
+		}
+		if err := json.NewEncoder(os.Stdout).Encode(m); err != nil {
+			Fatalf("Encode MemoryUsage failed: %v", err)
+		}
+	} else {
+		m, err := cont.UsageFD()
+		if err != nil {
+			Fatalf("usagefd failed: %v", err)
+		}
+
+		mapped, unknown, total, err := m.Fetch()
+		if err != nil {
+			Fatalf("Fetch memory usage failed: %v", err)
+		}
+
+		fmt.Printf("Mapped %v, Unknown %v, Total %v\n", mapped, unknown, total)
+	}
+	return subcommands.ExitSuccess
+}
diff --git a/runsc/container/container.go b/runsc/container/container.go
index d1f979eb2..381f57574 100644
--- a/runsc/container/container.go
+++ b/runsc/container/container.go
@@ -652,6 +652,24 @@ func (c *Container) Cat(files []string, out *os.File) error {
 	return c.Sandbox.Cat(c.ID, files, out)
 }
 
+// Usage displays memory used by the application.
+func (c *Container) Usage(full bool) (control.MemoryUsage, error) {
+	log.Debugf("Usage in container, cid: %s, full: %v", c.ID, full)
+	return c.Sandbox.Usage(c.ID, full)
+}
+
+// UsageFD shows application memory usage using two donated FDs.
+func (c *Container) UsageFD() (*control.MemoryUsageRecord, error) {
+	log.Debugf("UsageFD in container, cid: %s", c.ID)
+	return c.Sandbox.UsageFD(c.ID)
+}
+
+// Reduce requests that the sentry attempt to reduce its memory usage.
+func (c *Container) Reduce(wait bool) error {
+	log.Debugf("Reduce in container, cid: %s", c.ID)
+	return c.Sandbox.Reduce(c.ID, wait)
+}
+
 // State returns the metadata of the container.
 func (c *Container) State() specs.State {
 	return specs.State{
diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go
index b15572a98..c8c6886c7 100644
--- a/runsc/sandbox/sandbox.go
+++ b/runsc/sandbox/sandbox.go
@@ -1020,6 +1020,59 @@ func (s *Sandbox) Cat(cid string, files []string, out *os.File) error {
 	return nil
 }
 
+// Usage sends the collect call for a container in the sandbox.
+func (s *Sandbox) Usage(cid string, Full bool) (control.MemoryUsage, error) {
+	log.Debugf("Usage sandbox %q", s.ID)
+	conn, err := s.sandboxConnect()
+	if err != nil {
+		return control.MemoryUsage{}, err
+	}
+	defer conn.Close()
+
+	var m control.MemoryUsage
+	err = conn.Call(boot.UsageCollect, &control.MemoryUsageOpts{
+		Full: Full,
+	}, &m)
+	return m, err
+}
+
+// UsageFD sends the usagefd call for a container in the sandbox.
+func (s *Sandbox) UsageFD(cid string) (*control.MemoryUsageRecord, error) {
+	log.Debugf("Usage sandbox %q", s.ID)
+	conn, err := s.sandboxConnect()
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	var m control.MemoryUsageFile
+	if err := conn.Call(boot.UsageUsageFD, &control.MemoryUsageFileOpts{
+		Version: 1,
+	}, &m); err != nil {
+		return nil, fmt.Errorf("UsageFD failed: %v", err)
+	}
+
+	if len(m.FilePayload.Files) != 2 {
+		return nil, fmt.Errorf("wants exactly two fds")
+	}
+
+	return control.NewMemoryUsageRecord(*m.FilePayload.Files[0], *m.FilePayload.Files[1])
+}
+
+// Reduce sends the reduce call for a container in the sandbox.
+func (s *Sandbox) Reduce(cid string, wait bool) error {
+	log.Debugf("Reduce sandbox %q", s.ID)
+	conn, err := s.sandboxConnect()
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	return conn.Call(boot.UsageReduce, &control.UsageReduceOpts{
+		Wait: wait,
+	}, nil)
+}
+
 // IsRunning returns true if the sandbox or gofer process is running.
 func (s *Sandbox) IsRunning() bool {
 	if s.Pid != 0 {