tasks: add Linux rdt support

Add support for configuring the Linux resctrl pseudo-filesystem with
goresctrl library. The functionality is integrated in the
"io.containerd.service.v1.tasks-service" plugin.

Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>

docs/man/containerd-config.toml.5.md

@@ -104,6 +104,12 @@ documentation.
   - **sched_core** Core scheduling is a feature that allows only trusted tasks
     to run concurrently on cpus sharing compute resources (eg: hyperthreads on
     a core). (Default: **false**)
+- **[plugins."io.containerd.service.v1.tasks-service"]** has one option:
+  - **rdt_config_file** (Linux only) specifies path to a configuration used for
+    configuring RDT (Default: **""**). Enables support for Intel RDT, a
+    technology for cache and memory bandwidth management.
+    See https://github.com/intel/goresctrl/blob/v0.2.0/doc/rdt.md#configuration
+    for details of the configuration file format.
 
 **oom_score**
 : The out of memory (OOM) score applied to the containerd daemon process (Default: 0)
@@ -193,6 +199,8 @@ imports = ["/etc/containerd/runtime_*.toml", "./debug.toml"]
   [plugins."io.containerd.runtime-shim.v2.shim"]
     platforms = ["linux/amd64"]
     sched_core = true
+  [plugins."io.containerd.service.v1.tasks-service"]
+    rdt_config_file = "/etc/rdt-config.yaml"
 ```
 
 ## BUGS

services/tasks/local.go

@@ -63,11 +63,18 @@ const (
 	stateTimeout = "io.containerd.timeout.task.state"
 )
 
+// Config for the tasks service plugin
+type Config struct {
+	// RdtConfigFile specifies the path to RDT configuration file
+	RdtConfigFile string `toml:"rdt_config_file" json:"rdtConfigFile"`
+}
+
 func init() {
 	plugin.Register(&plugin.Registration{
 		Type:     plugin.ServicePlugin,
 		ID:       services.TasksService,
 		Requires: tasksServiceRequires,
+		Config:   &Config{},
 		InitFn:   initFunc,
 	})
 
@@ -75,6 +82,7 @@ func init() {
 }
 
 func initFunc(ic *plugin.InitContext) (interface{}, error) {
+	config := ic.Config.(*Config)
 	runtimes, err := loadV1Runtimes(ic)
 	if err != nil {
 		return nil, err
@@ -128,6 +136,11 @@ func initFunc(ic *plugin.InitContext) (interface{}, error) {
 	for _, t := range v2Tasks {
 		l.monitor.Monitor(t, nil)
 	}
+
+	if err := initRdt(config.RdtConfigFile); err != nil {
+		log.G(ic.Context).WithError(err).Errorf("RDT initialization failed")
+	}
+
 	return l, nil
 }
 

services/tasks/rdt_default.go

@@ -0,0 +1,24 @@
+//go:build !linux || no_rdt
+// +build !linux no_rdt
+
+/*
+   Copyright The containerd 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 tasks
+
+func RdtEnabled() bool { return false }
+
+func initRdt(configFilePath string) error { return nil }

services/tasks/rdt_linux.go

@@ -0,0 +1,50 @@
+//go:build linux && !no_rdt
+// +build linux,!no_rdt
+
+/*
+   Copyright The containerd 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 tasks
+
+import (
+	"github.com/containerd/containerd/log"
+
+	"github.com/intel/goresctrl/pkg/rdt"
+	"github.com/pkg/errors"
+)
+
+const (
+	// ResctrlPrefix is the prefix used for class/closid directories under the resctrl filesystem
+	ResctrlPrefix = ""
+)
+
+func initRdt(configFilePath string) error {
+	if configFilePath == "" {
+		log.L.Debug("No RDT config file specified, RDT not configured")
+		return nil
+	}
+
+	if err := rdt.Initialize(ResctrlPrefix); err != nil {
+		return errors.Wrap(err, "RDT not enabled")
+	}
+
+	if err := rdt.SetConfigFromFile(configFilePath, true); err != nil {
+		return err
+	}
+
+	return nil
+
+}