[PATCH] [1/4] SLAB: Handle node-not-up case in fallback_alloc() v2

[Andi Kleen <andi@firstfloor.org>]

When fallback_alloc() runs the node of the CPU might not be initialized yet.
Handle this case by allocating in another node.

v2: Try to allocate from all nodes (David Rientjes)

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 mm/slab.c |   19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Index: linux-2.6.32-memhotadd/mm/slab.c
===================================================================
--- linux-2.6.32-memhotadd.orig/mm/slab.c
+++ linux-2.6.32-memhotadd/mm/slab.c
@@ -3188,7 +3188,24 @@ retry:
 		if (local_flags & __GFP_WAIT)
 			local_irq_enable();
 		kmem_flagcheck(cache, flags);
-		obj = kmem_getpages(cache, local_flags, numa_node_id());
+
+		/*
+		 * Node not set up yet? Try one that the cache has been set up
+		 * for.
+		 */
+		nid = numa_node_id();
+		if (cache->nodelists[nid] == NULL) {
+			for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+				nid = zone_to_nid(zone);
+				if (cache->nodelists[nid]) {
+					obj = kmem_getpages(cache, local_flags, nid);
+					if (obj)
+						break;
+				}
+			}
+		} else
+			obj = kmem_getpages(cache, local_flags, nid);
+
 		if (local_flags & __GFP_WAIT)
 			local_irq_disable();
 		if (obj) {