从redhat 6开始引入了Transparent HugePages,但是oracle一直建议disable 它,而使用标准HugePages方式.对于6和7的禁用方式有一些区别.
linux 6
修改/etc/grub.conf之后重启系统生效

vi /etc/grub.conf
title Oracle Linux Server (2.6.32-300.25.1.el6uek.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-300.25.1.el6uek.x86_64 ro root=LABEL=/  transparent_hugepage=never
        initrd /initramfs-2.6.32-300.25.1.el6uek.x86_64.img

linux 7
修改/etc/default/grub然后执行grub2-mkconfig并重启系统生效

[root@xifenfei u01]# vi /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="nomodeset vconsole.font=latarcyrheb-sun16 vconsole.keymap=us crashkernel=auto
                    biosdevname=0 transparent_hugepage=never"
GRUB_DISABLE_RECOVERY="true"
~
[root@xifenfei u01]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-514.26.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.26.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-cb0b6b4de89a4fe4acfc8774c2f01486
Found initrd image: /boot/initramfs-0-rescue-cb0b6b4de89a4fe4acfc8774c2f01486.img
done

临时禁用
该方法对于linux 6和7均有效,不用重启系统

if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
   echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
   echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi