tree a1cc7326d3a12bed79071559e2d4e8d43fb14814
parent 60ab3244ec85c44276c585a2a20d3750402e1cf4
author Andrea Arcangeli <aarcange@redhat.com> 1294962439 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1294968768 -0800

thp: KSM on THP

This makes KSM full operational with THP pages.  Subpages are scanned
while the hugepage is still in place and delivering max cpu performance,
and only if there's a match and we're going to deduplicate memory, the
single hugepages with the subpage match is split.

There will be no false sharing between ksmd and khugepaged.  khugepaged
won't collapse 2m virtual regions with KSM pages inside.  ksmd also should
only split pages when the checksum matches and we're likely to split an
hugepage for some long living ksm page (usual ksm heuristic to avoid
sharing pages that get de-cowed).

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>