Re: kernel BUG in __cache_alloc_node at linux-2.6.git/mm/slab.c:3177!

From: Christoph Lameter
Date: Fri Oct 20 2006 - 13:48:21 EST


Here is the patch:

Slab: Do not fallback to nodes that have not been bootstrapped yet

The zonelist may contain zones of nodes that have not been bootstrapped
and we will oops if we try to allocate from those zones. So check if the
node information for the slab and the node have been setup before
attempting an allocation. If it has not been setup then skip that zone.

Usually we will not encounter this situation since the slab bootstrap
code avoids falling back before we have setup the respective nodes but we
seem to have a special needs for pppc.

Signed-off-by: Christoph Lameter <clameter@xxxxxxx>

Index: linux-2.6.19-rc2-mm1/mm/slab.c
===================================================================
--- linux-2.6.19-rc2-mm1.orig/mm/slab.c 2006-10-20 12:39:02.000000000 -0500
+++ linux-2.6.19-rc2-mm1/mm/slab.c 2006-10-20 12:41:04.137684581 -0500
@@ -3160,12 +3160,15 @@ void *fallback_alloc(struct kmem_cache *
struct zone **z;
void *obj = NULL;

- for (z = zonelist->zones; *z && !obj; z++)
+ for (z = zonelist->zones; *z && !obj; z++) {
+ int nid = zone_to_nid(*z);
+
if (zone_idx(*z) <= ZONE_NORMAL &&
- cpuset_zone_allowed(*z, flags))
+ cpuset_zone_allowed(*z, flags) &&
+ cache->nodelists[nid])
obj = __cache_alloc_node(cache,
- flags | __GFP_THISNODE,
- zone_to_nid(*z));
+ flags | __GFP_THISNODE, nid);
+ }
return obj;
}


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/