linux/arch/metag
Naoya Horiguchi 83467efbdb mm: migrate: check movability of hugepage in unmap_and_move_huge_page()
Currently hugepage migration works well only for pmd-based hugepages
(mainly due to lack of testing,) so we had better not enable migration of
other levels of hugepages until we are ready for it.

Some users of hugepage migration (mbind, move_pages, and migrate_pages) do
page table walk and check pud/pmd_huge() there, so they are safe.  But the
other users (softoffline and memory hotremove) don't do this, so without
this patch they can try to migrate unexpected types of hugepages.

To prevent this, we introduce hugepage_migration_support() as an
architecture dependent check of whether hugepage are implemented on a pmd
basis or not.  And on some architecture multiple sizes of hugepages are
available, so hugepage_migration_support() also checks hugepage size.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.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>
2013-09-11 15:57:49 -07:00
..
boot metag: tz1090: instantiate gpio-tz1090-pdc 2013-07-22 10:55:31 +01:00
configs metag: minimal TZ1090 (Comet) SoC infrastructure 2013-06-13 12:14:07 +01:00
include arch/metag fixes for v3.11 2013-07-10 10:14:35 -07:00
kernel metag: delete __cpuinit usage from all metag files 2013-07-14 19:36:54 -04:00
lib metag: move EXPORT_SYMBOL(csum_partial) to metag_ksyms.c 2013-07-04 10:00:02 +01:00
mm mm: migrate: check movability of hugepage in unmap_and_move_huge_page() 2013-09-11 15:57:49 -07:00
oprofile metag: OProfile support 2013-03-15 13:21:05 +00:00
tbx metag: Build infrastructure 2013-03-02 20:09:54 +00:00
Kconfig consolidate per-arch stack overflow debugging options 2013-07-04 11:25:39 -07:00
Kconfig.debug consolidate per-arch stack overflow debugging options 2013-07-04 11:25:39 -07:00
Kconfig.soc metag: tz1090: select and instantiate gpio-tz1090 2013-07-22 10:55:31 +01:00
Makefile metag: minimal TZ1090 (Comet) SoC infrastructure 2013-06-13 12:14:07 +01:00