thp: add pmd mangling functions to x86
authorAndrea Arcangeli <aarcange@redhat.com>
Thu, 13 Jan 2011 23:46:41 +0000 (15:46 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 14 Jan 2011 01:32:40 +0000 (17:32 -0800)
commitdb3eb96f4e6281b84dd33c8980dacc27f2efe177
tree0746ed213778d8cb9ec18c1c7c16490c233d178b
parente2cda322648122dc400c85ada80eaddbc612ef6a
thp: add pmd mangling functions to x86

Add needed pmd mangling functions with symmetry with their pte
counterparts.  pmdp_splitting_flush() is the only new addition on the pmd_
methods and it's needed to serialize the VM against split_huge_page.  It
simply atomically sets the splitting bit in a similar way
pmdp_clear_flush_young atomically clears the accessed bit.
pmdp_splitting_flush() also has to flush the tlb to make it effective
against gup_fast, but it wouldn't really require to flush the tlb too.
Just the tlb flush is the simplest operation we can invoke to serialize
pmdp_splitting_flush() against gup_fast.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/include/asm/pgtable.h
arch/x86/include/asm/pgtable_64.h
arch/x86/mm/pgtable.c