[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: PAT support
On Wed, May 19, 2010 at 01:23:19PM +1000, matthew green wrote:
> what's PAT? could you add a comment to pat.c, explaining what this
> code is for?
The Page Attribute Table (PAT, also known as Page Allocation
Table) 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.
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
My understanding is, this is most typically for GPUs. Time to revisit
the hacks in our drm(4) code...
Masao Uebayashi / Tombi Inc. / Tel: +81-90-9141-4635
Main Index |
Thread Index |