Recompile Linux Kernel To Enable HUGEPAGES On Raspberry Pi 5

gistfile1.md

HUGEPAGES is diabled by default in the Raspberry Pi Linux kernel. To enable HUGEPAGES the kernel must be recompiled.

Tested and works as expected on Raspberry Pi 4B, 400, CM4, and 5.

Install dependencies

sudo apt update sudo apt install -y git build-essential bc bison kmod cpio flex libncurses5-dev libelf-dev libssl-dev

Clone the Raspberry Pi Linux Kernel Repository

git clone --depth=1 https://github.com/raspberrypi/linux cd linux

Backup .config file before customizing

cp .config .config.backup
The .config file is not present until the following command is ran which generates a fresh basic .config file.

Configure Kernel

KERNEL=kernel_2712 make bcm2712_defconfig

Enable hugepage support in the kernel configuration - One line at a time

sed -i 's/# CONFIG_HUGETLBFS.*/CONFIG_HUGETLBFS=y/' .config
sed -i 's/# CONFIG_TRANSPARENT_HUGEPAGE.*/CONFIG_TRANSPARENT_HUGEPAGE=y/' .config
sed -i 's/# CONFIG_HUGETLB_PAGE.*/CONFIG_HUGETLB_PAGE=y/' .config 
sed -i 's/# CONFIG_ARCH_HAS_HUGEPD.*/CONFIG_ARCH_HAS_HUGEPD=y/' .config
sed -i 's/# CONFIG_HUGETLB_PAGE_SIZE_VARIABLE.*/CONFIG_HUGETLB_PAGE_SIZE_VARIABLE=y/' .config
sed -i 's/# CONFIG_ARCH_WANT_GENERAL_HUGETLB.*/CONFIG_ARCH_WANT_GENERAL_HUGETLB=y/' .config
sed -i 's/# CONFIG_SYSFS.*/CONFIG_SYSFS=y/' .config
sed -i 's/# CONFIG_CHECKPOINT_RESTORE.*/CONFIG_CHECKPOINT_RESTORE=y/' .config
sed -i 's/# CONFIG_HIGH_RES_TIMERS.*/CONFIG_HIGH_RES_TIMERS=y/' .config

Build the kernel

make -j4 Image.gz modules dtbs

Install the kernel

sudo make modules_install
sudo cp arch/arm64/boot/dts/broadcom/*.dtb /boot/firmware/
sudo cp arch/arm64/boot/dts/overlays/*.dtb* /boot/firmware/overlays/
sudo cp arch/arm64/boot/dts/overlays/README /boot/firmware/overlays/
sudo cp arch/arm64/boot/Image.gz /boot/firmware/$KERNEL.img

sudo cp arch/arm64/boot/Image.gz /boot/firmware/kernel8hp.img

Edit the config.txt file and specify the new kernel:
sudo nano /boot/firmware/config.txt
Add the following line and comment out and other kernel= lines if present. kernel=kernel8hp.img

Reboot and kernel will be installed and active

Check current HUGEPAGES:
Display HUGEPAGE information grep -i huge /proc/meminfo Displays the number of HUGEPAGES currently allocated grep HugePages_Total /proc/meminfo