Change page size on Ubuntu

To install a 64 K page size kernel on Ubuntu 22.04 LTS or later , follow the steps below.

Verify the current page size

Verify you’re using a 4KB base-page-size kernel by entering the following commands:

    

        
        
getconf PAGESIZE
uname -r

    

The output should be similar to below. The kernel flavor (the string after the version number) may vary, but the first line should always be 4096.

    

        
        4096
6.1.0-34-cloud-arm64

        
    

The 4096 indicates the current page size is 4 KB. If you see a value that is different, you are already using a page size other than 4096 (4K). On Arm systems, the valid options are 4K, 16K, and 64K.

Install the required dependencies and the 64K kernel

Run the commands to install the required software:

    

        
        
sudo apt-get -y update
sudo apt-get -y install git build-essential autoconf automake libtool gdb wget linux-generic-64k

    

Next, run the following command to configure GRUB to load the 64K kernel by default:

    

        
        
echo "GRUB_FLAVOUR_ORDER=generic-64k" | sudo tee /etc/default/grub.d/local-order.cfg 

    

Update GRUB and reboot

Commit your changes to GRUB and reboot by entering the following:

    

        
        
sudo update-grub 
sudo reboot 

    

Upon reboot, check the kernel page size and name to confirm the changes:

    

        
        
getconf PAGESIZE
uname -r

    

The output shows the 64K kernel is running:

    

        
        65536
6.8.0-59-generic-64k

        
    

This indicates that the current page size is 64K and that you are running the new 64K kernel.

Revert to the 4K kernel

To revert to the original 4K kernel, run the following commands:

    

        
        
echo "GRUB_FLAVOUR_ORDER=generic" | sudo tee /etc/default/grub.d/local-order.cfg 
sudo update-grub 
sudo reboot 

    

Upon reboot, verify you’re on a 4KB pagesize kernel by entering the following commands:

    

        
        
getconf PAGESIZE
uname -r

    

The output shows the 4K kernel is running:

    

        
        4096
6.1.0-34-cloud-arm64

        
    

The 4096 indicates the current page size has been reverted to 4KB.