【转】怎么在RHEL8中禁用透明的大页？

How to disable transparent hugepage (THP) on Red Hat Enterprise Linux 8?

https://access.redhat.com/solutions/3799821

SOLUTION 已验证 - 已更新 2019年二月25日17:28 - 

English 

环境

• Red Hat Enterprise Linux 8
• Transparent HugePage (THP)

问题

• How to disable transparent Hugepage (THP) on Red Hat Enterprise Linux 8?

决议

• The transparent hugepage (THP) can be disabled by booting the system with the kernel boot parameter transparent_hugepage=never.

Command Line: The grub2-editenv command can be used to set the kernel parameter transparent_hugepage=never at the end of kerneloptsin the file /boot/grub2/grubenv.

• Get the current kernel command line parameters.

Raw

# grub2-editenv - list | grep kernelopts
kernelopts=root=/dev/mapper/rhel-root ro resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap 

• Set the kernel parameter transparent_hugepage=never by using the grub2-editenv command.

Raw

# grub2-editenv - set "kernelopts=root=/dev/mapper/rhel-root ro resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap transparent_hugepage=never"

• Verify the changes.

Raw

# grub2-editenv - list | grep kernelopts
kernelopts=root=/dev/mapper/rhel-root ro resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap transparent_hugepage=never

• Reboot the system for changes to take effect.

Raw

# reboot

• Check the following files to confirm that the transparent hugepage (THP) is disabled.

Raw

# cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise [never]

# grep AnonHugePages: /proc/meminfo 
AnonHugePages:         0 kB

# grep nr_anon_transparent_hugepages /proc/vmstat
nr_anon_transparent_hugepages 0

Configuration File: The kernel boot parameter transparent_hugepage=never can be directly set at the end of kernelopts in the file /boot/grub2/grubenv.

• Edit file /boot/grub2/grubenv and set the kernel boot parameter transparent_hugepage=never at the end of kernelopts.

Eg:

Raw

# cat /boot/grub2/grubenv
# GRUB Environment Block
saved_entry=d956a05b4c9341b9a364b20b801afc12-4.18.0-64.el8.x86_64
boot_success=0
boot_indeterminate=0
kernelopts=root=/dev/mapper/rhel-root ro resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap transparent_hugepage=never

• Reboot the system for changes to take effect.

Raw

# reboot

• Check the following files to confirm that the transparent hugepage (THP) is disabled.

Raw

# cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise [never]

# grep AnonHugePages: /proc/meminfo 
AnonHugePages:         0 kB

# grep nr_anon_transparent_hugepages /proc/vmstat
nr_anon_transparent_hugepages 0