Allow huge page allocations to use GFP_HIGH_MOVABLE
Huge pages are not movable so are not allocated from ZONE_MOVABLE. However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time. This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.
This patch adds a new sysctl called hugepages_treat_as_movable. When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.
[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4c0f999..9f4e9b9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1203,7 +1203,8 @@
#ifdef CONFIG_HUGETLBFS
/* Return a zonelist suitable for a huge page allocation. */
-struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr)
+struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
+ gfp_t gfp_flags)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
@@ -1211,7 +1212,7 @@
unsigned nid;
nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
- return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER);
+ return NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_flags);
}
return zonelist_policy(GFP_HIGHUSER, pol);
}