PAT and identity mapped pages.

AlexandreFressange deco33000 at
Fri Nov 20 10:15:03 UTC 2015


On x86_64, every memory page entry has a bit (4) to control its cache method: write-back or write-through.

But even on identity mapped pages, you still use paging. Say, I want a page to be uncached; I can use the PAT to Uncached.

In this case, what happens to the bit 4 of the accessed page? is it ignored?



More information about the freebsd-amd64 mailing list