SUSE/saptune

package note

import (
    "github.com/SUSE/saptune/system"
    "strconv"
    "strings"
)

// section [vm]
// Manipulate /sys/kernel/mm switches.

// GetVMVal initialise the memory management structure with the current
// system settings
func GetVMVal(key string) (string, string) {
    var val string
    info := ""
    switch key {
    case "THP":
        val, _ = system.GetSysChoice(system.SysKernelTHPEnabled)
    case "KSM":
        ksmval, _ := system.GetSysInt(system.SysKSMRun)
        val = strconv.Itoa(ksmval)
    }
    return val, info
}

// OptVMVal optimises the memory management structure with the settings
// from the configuration file
func OptVMVal(key, cfgval string) string {
    val := strings.ToLower(cfgval)
    switch key {
    case "THP":
        if val != "always" && val != "madvise" && val != "never" {
            system.WarningLog("wrong selection for THP. Now set to 'never' to disable transarent huge pages")
            val = "never"
        }
    case "KSM":
        if val != "1" && val != "0" {
            system.WarningLog("wrong selection for KSM. Now set to default value '0'")
            val = "0"
        }
    }
    return val
}

// SetVMVal applies the settings to the system
func SetVMVal(key, value string) error {
    var err error
    switch key {
    case "THP":
        err = system.SetSysString(system.SysKernelTHPEnabled, value)
    case "KSM":
        ksmval, _ := strconv.Atoi(value)
        err = system.SetSysInt(system.SysKSMRun, ksmval)
    }
    return err
}