How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7, 8 and 9

・ How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7, 8 and 9.pdf |

Environment

  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • transparent hugepages (THP)
  • tuned

Issue

  • How to disable transparent hugepages (THP) on Red Hat Enterprise Linux 7, 8 and 9
  • Disabling transparent hugepages (THP) on Red Hat Enterprise Linux 7 is not taking effect.

Resolution

Follow the steps below.

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.

cp -p /etc/default/grub{,.bak.`date +%Y%m%d`}
sed -i '/GRUB_CMDLINE_LINUX/ s/"$/ transparent_hugepage=never"/' /etc/default/grub

Verify the parameter is set correctly, like GRUB_CMDLINE_LINUX="rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap ... transparent_hugepage=never

sed -n '/GRUB_CMDLINE_LINUX/p' /etc/default/grub

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.
Detect whether Linux runs in UEFI or BIOS mode: [ /sys/firmware/efi ] && echo UEFI || echo BIOS

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

Reboot the system and verify option has been added.

shutdown -r now

Verify the parameter is set correctly

~]$ cat /proc/cmdline
~]$ cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise [never]

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

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:

~]$ sudo tuned-adm active
Current active profile: throughput-performance

Current active profile: throughput-performance
To create customized profile, create a new directory in /etc/tuned directory with desired profile name.

sudo mkdir /etc/tuned/profile-nothp

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

sudo bash -c "cat > /etc/tuned/profile-nothp/tuned.conf" <<EOF
[main]
include=throughput-performance

[vm]
transparent_hugepages=never
EOF

Make the script executable:

sudo chmod +x /etc/tuned/profile-nothp/tuned.conf

Enable myprofile like so:

sudo tuned-adm profile profile-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

OR

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.