Fix cgroup hugetlb size prefix for kB

Mitigation of the issue fixed in master where hugetlb prefix for "KiB" is "kB" in runc, but the correct is "KB" See https://github.com/opencontainers/runc/pull/2065 and https://github.com/kubernetes/kubernetes/pull/78495 for more info. --- The hugetlb cgroup control files (introduced here in 2012: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=abb8206cb0773) use "KB" and not "kB" (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/hugetlb_cgroup.c?h=v5.0#n349). The behavior in the kernel has not changed since the introduction, and the current code using "kB" will therefore fail on devices with small amounts of ram (see #77169) running a kernel with config flag CONFIG_HUGETLBFS=y As seen from the code in "mem_fmt" inside hugetlb_cgroup.c, only "KB", "MB" and "GB" are used, so the others may be removed as well. Here is a real world example of the files inside the "/sys/kernel/mm/hugepages/" directory: "hugepages-64kB" "hugepages-2048kB" "hugepages-32768kB" "hugepages-1048576kB" And the corresponding cgroup files: "hugetlb.64KB._____" "hugetlb.2MB._____" "hugetlb.32MB._____" "hugetlb.1GB._____"

Fix cgroup hugetlb size prefix for kB
820a717b · Odin Ugedal · e4983005 · 820a717b · 820a717b
Commit 820a717b authored Jul 07, 2019 by Odin Ugedal
Hide whitespace changes
Inline Side-by-side

Showing with 10 additions and 1 deletion

cgroup_manager_linux.go pkg/kubelet/cm/cgroup_manager_linux.go +1 -1

container_manager_linux.go pkg/kubelet/cm/container_manager_linux.go +9 -0

No files found.
--- a/pkg/kubelet/cm/cgroup_manager_linux.go
+++ b/pkg/kubelet/cm/cgroup_manager_linux.go
@@ -51,7 +51,7 @@ const (

 // hugePageSizeList is useful for converting to the hugetlb canonical unit
 // which is what is expected when interacting with libcontainer
-var hugePageSizeList = []string{"B", "kB", "MB", "GB", "TB", "PB"}
+var hugePageSizeList = []string{"B", "KB", "MB", "GB", "TB", "PB"}

 var RootCgroupName = CgroupName([]string{})


--- a/pkg/kubelet/cm/container_manager_linux.go
+++ b/pkg/kubelet/cm/container_manager_linux.go
@@ -200,6 +200,15 @@ func validateSystemRequirements(mountUtil mount.Interface) (features, error) {
 // Takes the absolute name of the specified containers.
 // Empty container name disables use of the specified container.
 func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.Interface, nodeConfig NodeConfig, failSwapOn bool, devicePluginEnabled bool, recorder record.EventRecorder) (ContainerManager, error) {
+	// Mitigation of the issue fixed in master where hugetlb prefix for page sizes with "KiB"
+	// is "kB" in runc, but the correct is "KB"
+	// See https://github.com/opencontainers/runc/pull/2065
+	// and https://github.com/kubernetes/kubernetes/pull/78495
+	// for more info.
+	for i, pageSize := range fs.HugePageSizes {
+		fs.HugePageSizes[i] = strings.ReplaceAll(pageSize, "kB", "KB")
+	}
+
 	subsystems, err := GetCgroupSubsystems()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get mounted cgroup subsystems: %v", err)