[PATCH] Add NUMA policy support for huge pages.

The huge_zonelist() function in the memory policy layer provides an list of
zones ordered by NUMA distance.  The hugetlb layer will walk that list looking
for a zone that has available huge pages but is also in the nodeset of the
current cpuset.

This patch does not contain the folding of find_or_alloc_huge_page() that was
controversial in the earlier discussion.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 30 insertions, 9 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 72f402cc9c9a..45c51ac63443 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -785,6 +785,34 @@ static unsigned offset_il_node(struct mempolicy *pol,
         return nid;
 }
 
+/* Determine a node number for interleave */
+static inline unsigned interleave_nid(struct mempolicy *pol,
+                 struct vm_area_struct *vma, unsigned long addr, int shift)
+{
+        if (vma) {
+                unsigned long off;
+
+                off = vma->vm_pgoff;
+                off += (addr - vma->vm_start) >> shift;
+                return offset_il_node(pol, vma, off);
+        } else
+                return interleave_nodes(pol);
+}
+
+/* Return a zonelist suitable for a huge page allocation. */
+struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr)
+{
+        struct mempolicy *pol = get_vma_policy(current, vma, addr);
+
+        if (pol->policy == MPOL_INTERLEAVE) {
+                unsigned nid;
+
+                nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
+                return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER);
+        }
+        return zonelist_policy(GFP_HIGHUSER, pol);
+}
+
 /* Allocate a page in interleaved policy.
    Own path because it needs to do special accounting. */
 static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
@@ -833,15 +861,8 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
 
         if (unlikely(pol->policy == MPOL_INTERLEAVE)) {
                 unsigned nid;
-                if (vma) {
-                        unsigned long off;
-                        off = vma->vm_pgoff;
-                        off += (addr - vma->vm_start) >> PAGE_SHIFT;
-                        nid = offset_il_node(pol, vma, off);
-                } else {
-                        /* fall back to process interleaving */
-                        nid = interleave_nodes(pol);
-                }
+
+                nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
                 return alloc_page_interleave(gfp, 0, nid);
         }
         return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol));