How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7

How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7

$ Solution 已验证 - 已更新2017年六月2日23:54 - English

环境

Red Hat Enterprise Linux 7

transparent hugepages (THP)

tuned

问题

How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7

Disabling transparent hugepages (THP) on Red Hat Enterprise Linux 7 is not taking effect.

决议

Follow the steps below

1.Add the "transparent_hugepage=never" kernel parameter option to the grub2 configuration file.

Append or change the "transparent_hugepage=never" kernel parameter

on the GRUB_CMDLINE_LINUX option in /etc/default/grub file. Only include the parameter once.

vim /etc/default/grub

GRUB_CMDLINE_LINUX="rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap ... transparent_hugepage=never"

2.Rebuild the /boot/grub2/grub.cfg file by running the grub2-mkconfig -o command as follows:

Please ensure to take a backup of the existing /boot/grub2/grub.cfg before rebuilding.

On BIOS-based machines: ~]# grub2-mkconfig -o /boot/grub2/grub.cfg

On UEFI-based machines: ~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

3.Reboot the system and verify option has been added

Reboot the system

# shutdown -r now

Verify the parameter is set correctly

# cat /proc/cmdline

正确的,应该含 transparent_hugepage=never

If Transparent Huge Pages (THP) is still not disabled, continue and use one of the options below.

Option 1: (Recommended) create a customized tuned profile with disabled THP

With this resolution we will create a customized version of the currently running profile. The customized version will disable THP.

Find out which profile is active, create a copy.

In the following example we currently use the throughput-performance profile:

# tuned-adm active

Current active profile: throughput-performance

To create customized profile, create a new directory in /etc/tuned directory with desired profile name.

# mkdir /etc/tuned/myprofile-nothp

Then create a new tuned.conf file for myprofile-nothp, and insert the new tuning info:

# cat /etc/tuned/myprofile-nothp/tuned.conf

[main]

include= throughput-performance

[vm]

transparent_hugepages=never

Make the script executable:

# chmod +x /etc/tuned/myprofile-nothp/tuned.conf

Enable myprofile like so:

# tuned-adm profile myprofile-nothp

This change will immediately take effect and persist reboots.

To verify if THP are disabled or not, run below command:

# cat /sys/kernel/mm/transparent_hugepage/enabled

Option 2: (Alternative) Disable tuned services

This resolution will disable the tuned services.

# systemctl stop tuned

# systemctl disable tuned

或者

# tuned-adm off

Now add "transparent_hugepage=never" kernel parameter in grub2 configuration file as explained in steps 1-3 above.

Reboot the server for changes to take effect.