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Page attribute table

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(Redirected from Page Allocation Table)

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]



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

See also



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