From: Christoph Lameter <clameter@sgi.com>

SLUB: Fix slab object counting.

We can only use the node value of the per cpu structure for counting if it
is positive. A negative value indicates that the slab is not valid.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Tested-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/slub.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff -puN mm/slub.c~slub-avoid-touching-page-struct-when-freeing-to-per-cpu-slab-fix mm/slub.c
--- a/mm/slub.c~slub-avoid-touching-page-struct-when-freeing-to-per-cpu-slab-fix
+++ a/mm/slub.c
@@ -3250,12 +3250,16 @@ static unsigned long slab_objects(struct
 
 	for_each_possible_cpu(cpu) {
 		struct page *page;
+		int node;
 		struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
 
 		if (!c)
 			continue;
 
 		page = c->page;
+		node = c->node;
+		if (node < 0)
+			continue;
 		if (page) {
 			if (flags & SO_CPU) {
 				int x = 0;
@@ -3265,9 +3269,9 @@ static unsigned long slab_objects(struct
 				else
 					x = 1;
 				total += x;
-				nodes[c->node] += x;
+				nodes[node] += x;
 			}
-			per_cpu[c->node]++;
+			per_cpu[node]++;
 		}
 	}
 
_