Page attribute table explained

The page attribute table (PAT) is a processor supplementary capability extension to the page table format of certain x86 and x86-64 microprocessors. Like memory type range registers (MTRRs), they allow for fine-grained control over how areas of memory are cached, and are a companion feature to the MTRRs.^[1]

Unlike MTRRs, which provide the ability to manipulate the behavior of caching for a limited number of fixed physical address ranges, Page Attribute Tables allow for such behavior to be specified on a per-page basis, greatly increasing the ability of the operating system to select the most efficient behavior for any given task.^[2]

Processors

The PAT is available on Pentium III and newer CPUs, and on non-Intel CPUs.

See also

• Write-combining

References

1. Web site: Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3A: System Programming Guide, Part 1 . Intel . 2017-05-30.
2. Web site: PAT (Page Attribute Table) in Linux kernel docs . 2020-06-02.

External links

• Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3A: System Programming Guide, Part 1 see chapter 11, section 12.