[PATCH] slab: allocate larger cache_cache if order 0 fails

kmem_cache_init() incorrectly assumes that the cache_cache object will fit
in an order 0 allocation.  On very large systems, this is not true.  Change
the code to try larger order allocations if order 0 fails.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 6ad6bd5a0b3e..61800b88e241 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1124,6 +1124,7 @@ void __init kmem_cache_init(void)
         struct cache_sizes *sizes;
         struct cache_names *names;
         int i;
+        int order;
 
         for (i = 0; i < NUM_INIT_LISTS; i++) {
                 kmem_list3_init(&initkmem_list3[i]);
@@ -1167,11 +1168,15 @@ void __init kmem_cache_init(void)
 
         cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, cache_line_size());
 
-        cache_estimate(0, cache_cache.buffer_size, cache_line_size(), 0,
-                       &left_over, &cache_cache.num);
+        for (order = 0; order < MAX_ORDER; order++) {
+                cache_estimate(order, cache_cache.buffer_size,
+                        cache_line_size(), 0, &left_over, &cache_cache.num);
+                if (cache_cache.num)
+                        break;
+        }
         if (!cache_cache.num)
                 BUG();
-
+        cache_cache.gfporder = order;
         cache_cache.colour = left_over / cache_cache.colour_off;
         cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
                                       sizeof(struct slab), cache_line_size());