mm, page_alloc: use masks and shifts when converting GFP flags to migrate types

This patch redefines which GFP bits are used for specifying mobility and
the order of the migrate types.  Once redefined it's possible to convert
GFP flags to a migrate type with a simple mask and shift.  The only
downside is that readers of OOM kill messages and allocation failures may
have been used to the existing values but scripts/gfp-translate will help.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2015-11-06 16:28:18 -08:00 committed by Linus Torvalds
parent 46e700abc4
commit 016c13daa5
2 changed files with 8 additions and 6 deletions

View file

@ -37,8 +37,8 @@
enum {
MIGRATE_UNMOVABLE,
MIGRATE_RECLAIMABLE,
MIGRATE_MOVABLE,
MIGRATE_RECLAIMABLE,
MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
MIGRATE_RESERVE = MIGRATE_PCPTYPES,
#ifdef CONFIG_CMA