mount: Fix hugepages support

Signed-off-by: Pradipta Banerjee <[email protected]>

grpc.go

@@ -1162,6 +1162,15 @@ func (a *agentGRPC) UpdateContainer(ctx context.Context, req *pb.UpdateContainer
 		resources.MemorySwap = req.Resources.Memory.Swap
 	}
 
+	if len(req.Resources.HugepageLimits) > 0 {
+		for _, l := range req.Resources.HugepageLimits {
+			resources.HugetlbLimit = append(resources.HugetlbLimit, &configs.HugepageLimit{
+				Pagesize: l.Pagesize,
+				Limit:    l.Limit,
+			})
+		}
+	}
+
 	if req.Resources.Pids != nil {
 		resources.PidsLimit = req.Resources.Pids.Limit
 	}

mount.go

@@ -10,6 +10,7 @@ import (
 	"bufio"
 	"context"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -26,12 +27,14 @@ import (
 )
 
 const (
-	type9pFs       = "9p"
-	typeVirtioFS   = "virtiofs"
-	typeRootfs     = "rootfs"
-	typeTmpFs      = "tmpfs"
-	procMountStats = "/proc/self/mountstats"
-	mountPerm      = os.FileMode(0755)
+	type9pFs             = "9p"
+	typeVirtioFS         = "virtiofs"
+	typeRootfs           = "rootfs"
+	typeTmpFs            = "tmpfs"
+	typeHugeTlbfs        = "hugetlbfs"
+	procMountStats       = "/proc/self/mountstats"
+	mountPerm            = os.FileMode(0755)
+	sysfsHugepagesPrefix = "/sys/kernel/mm/hugepages/"
 )
 
 var flagList = map[string]int{
@@ -111,6 +114,13 @@ func mount(source, destination, fsType string, flags int, options string) error
 		absSource = source
 	case typeTmpFs:
 		absSource = source
+	case typeHugeTlbfs:
+		absSource = source
+		//Allocate hugepages before mount
+		///sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
+		///sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
+		//options eg "pagesize=2048,size=107374182"
+		allocateHugePages(options)
 	default:
 		absSource, err = filepath.EvalSymlinks(source)
 		if err != nil {
@@ -132,6 +142,36 @@ func mount(source, destination, fsType string, flags int, options string) error
 	return nil
 }
 
+// Allocate hugepages by writing to sysfs
+func allocateHugePages(options string) error {
+
+	agentLog.WithField("HugePagesOption", options).Info("HugePages option string")
+
+	//options eg "pagesize=2048,size=107374182"
+	opt := strings.Split(options, ",")
+	pageSizeStr := strings.TrimPrefix(opt[0], "pagesize=")
+	pageSize, err := strconv.ParseInt(pageSizeStr, 10, 64)
+	if err != nil {
+		return grpcStatus.Errorf(codes.Internal, "Incorrect hugepage size %v", pageSizeStr)
+	}
+	//sysfs entry is always of the form hugepages-${size}kB
+	//Ref: https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt
+	pageSizeKbStr := strconv.FormatInt((pageSize/1024), 10) + "kB"
+	sysfsHugepagesPath := sysfsHugepagesPrefix + "hugepages-" + pageSizeKbStr + "/" + "nr_hugepages"
+
+	sizeStr := strings.TrimPrefix(opt[1], "size=")
+	size, err := strconv.ParseInt(sizeStr, 10, 64)
+	if err != nil {
+		return grpcStatus.Errorf(codes.Internal, "Incorrect total size of hugepages %v", sizeStr)
+	}
+	numpages := strconv.FormatInt((size / pageSize), 10)
+	if err := ioutil.WriteFile(sysfsHugepagesPath, []byte(numpages), 0644); err != nil {
+		return grpcStatus.Errorf(codes.Internal, "Could not allocate hugepages")
+	}
+
+	return nil
+}
+
 // ensureDestinationExists will recursively create a given mountpoint. If directories
 // are created, their permissions are initialized to mountPerm
 func ensureDestinationExists(source, destination string, fsType string) error {