Allocate 3rd-level pagetables from highmem

configname: CONFIG_HIGHPTE

Linux Kernel Configuration
└─>Processor type and features
└─>Allocate 3rd-level pagetables from highmem
In linux kernel since version 2.6.12  
The VM uses one page table entry for each page of physical memory.
For systems with a lot of RAM, this can be wasteful of precious
low memory. Setting this option will put user-space page table
entries in high memory.

depends
CONFIG_HIGHMEM