migrate: add hugepage migration code to migrate_pages()
authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Wed, 11 Sep 2013 21:22:03 +0000 (14:22 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Sep 2013 22:57:48 +0000 (15:57 -0700)
commite2d8cf405525d83e6ca42969be460f94b0339798
treebf36312ef5b29802dcca7e0849596a128042b0db
parentb8ec1cee5a4375c1244b85709138a2eac2d89cb6
migrate: add hugepage migration code to migrate_pages()

Extend check_range() to handle vma with VM_HUGETLB set.  We will be able
to migrate hugepage with migrate_pages(2) after applying the enablement
patch which comes later in this series.

Note that for larger hugepages (covered by pud entries, 1GB for x86_64 for
example), we simply skip it now.

Note that using pmd_huge/pud_huge assumes that hugepages are pointed to by
pmd/pud.  This is not true in some architectures implementing hugepage
with other mechanisms like ia64, but it's OK because pmd_huge/pud_huge
simply return 0 in such arch and page walker simply ignores such
hugepages.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mempolicy.c