Added conversion for cpu.weight v2

Signed-off-by: Boris Popovschi <[email protected]>

libcontainer/cgroups/utils.go

@@ -586,3 +586,12 @@ func isEINVAL(err error) bool {
 		return false
 	}
 }
+
+// Since the OCI spec is designed for cgroup v1, in some cases
+// there is need to convert from the cgroup v1 configuration to cgroup v2
+// the formula for cpuShares is y = (1 + ((x - 2) * 9999) / 262142)
+// convert from [2-262144] to [1-10000]
+// 262144 comes from Linux kernel definition "#define MAX_SHARES (1UL << 18)"
+func ConvertCPUSharesToCgroupV2Value(cpuShares uint64) uint64 {
+	return (1 + ((cpuShares-2)*9999)/262142)
+}

libcontainer/specconv/spec_linux.go

@@ -11,6 +11,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/opencontainers/runc/libcontainer/cgroups"
+
 	"github.com/opencontainers/runc/libcontainer/configs"
 	"github.com/opencontainers/runc/libcontainer/seccomp"
 	libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils"
@@ -405,6 +407,9 @@ func CreateCgroupConfig(opts *CreateOpts) (*configs.Cgroup, error) {
 		if r.CPU != nil {
 			if r.CPU.Shares != nil {
 				c.Resources.CpuShares = *r.CPU.Shares
+
+				//CpuWeight is used for cgroupv2 and should be converted
+				c.Resources.CpuWeight = cgroups.ConvertCPUSharesToCgroupV2Value(c.Resources.CpuShares)
 			}
 			if r.CPU.Quota != nil {
 				c.Resources.CpuQuota = *r.CPU.Quota

update.go

@@ -8,6 +8,8 @@ import (
 	"os"
 	"strconv"
 
+	"github.com/opencontainers/runc/libcontainer/cgroups"
+
 	"github.com/docker/go-units"
 	"github.com/opencontainers/runc/libcontainer/configs"
 	"github.com/opencontainers/runc/libcontainer/intelrdt"
@@ -253,6 +255,8 @@ other options are ignored.
 		config.Cgroups.Resources.CpuPeriod = *r.CPU.Period
 		config.Cgroups.Resources.CpuQuota = *r.CPU.Quota
 		config.Cgroups.Resources.CpuShares = *r.CPU.Shares
+		//CpuWeight is used for cgroupv2 and should be converted
+		config.Cgroups.Resources.CpuWeight = cgroups.ConvertCPUSharesToCgroupV2Value(*r.CPU.Shares)
 		config.Cgroups.Resources.CpuRtPeriod = *r.CPU.RealtimePeriod
 		config.Cgroups.Resources.CpuRtRuntime = *r.CPU.RealtimeRuntime
 		config.Cgroups.Resources.CpusetCpus = r.CPU.Cpus