marius 3179fa4baa Copying pages via temporary mappings in the !DMAP case of pmap_copy_pages()
involves updating the corresponding page tables followed by accesses to the
pages in question. This sequence is subject to the situation exactly described
in the "AMD64 Architecture Programmer's Manual Volume 2: System Programming"
rev. 3.23, "7.3.1 Special Coherency Considerations" [1, p. 171 f.]. Therefore,
issuing the INVLPG right after modifying the PTE bits is crucial (see also
r269050).
For the amd64 PMAP code, the order of instructions was already correct. The
above fact still is worth documenting, though.

1: http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2012/10/24593_APM_v21.pdf

Reviewed by:	alc
Sponsored by:	Bally Wulff Games & Entertainment GmbH
2014-07-24 10:12:22 +00:00
..
2014-07-23 15:53:29 +00:00
2014-07-24 01:38:11 +00:00
2014-07-24 01:38:11 +00:00