Chapter 2. The 64k page size kernel

kernel-64k is an additional, optional 64-bit ARM architecture kernel package that supports 64k pages. This additional kernel exists alongside the RHEL 9 for ARM kernel which supports 4k pages.

Optimal system performance directly relates to different memory configuration requirements. These requirements are addressed by the two variants of kernel, each suitable for different workloads. RHEL 9 on 64-bit ARM hardware thus offers two MMU page sizes:

  • 4k pages kernel for efficient memory usage in smaller environments,
  • kernel-64k for workloads with large, contiguous memory working sets.

The 4k pages kernel and kernel-64k do not differ in the user experience as the user space is the same. You can choose the variant that addresses your situation the best.

4k pages kernel

Use 4k pages for more efficient memory usage in smaller environments, such as those in Edge and lower-cost, small cloud instances. In these environments, increasing the physical system memory amounts is not practical due to space, power, and cost constraints. Also, not all 64-bit ARM architecture processors support a 64k page size.

The 4k pages kernel supports graphical installation using Anaconda, system or cloud image-based installations, as well as advanced installations using Kickstart.


The 64k page size kernel is a useful option for large datasets on ARM platforms. kernel-64k is suitable for memory-intensive workloads as it has significant gains in overall system performance, namely in large database, HPC, and high network performance.

You must choose page size on 64-bit ARM architecture systems at the time of installation. You can install kernel-64k only by Kickstart by adding the kernel-64k package to the package list in the Kickstart file.