Re: crash in kmem_cache_init

Christoph Lameter
2008-01-17T14:31:09Z

On Thu, 17 Jan 2008, Pekka Enberg wrote:

> Looks similar to the one discussed on linux-mm ("[BUG] at
> mm/slab.c:3320" thread). Christoph?

Right. Try the latest version of the patch to fix it:

Index: linux-2.6/mm/slab.c
===================================================================
--- linux-2.6.orig/mm/slab.c 2008-01-03 12:26:42.000000000 -0800
+++ linux-2.6/mm/slab.c 2008-01-09 15:59:49.000000000 -0800
@@ -2977,7 +2977,10 @@ retry:
}
l3 = cachep->nodelists[node];

- BUG_ON(ac->avail > 0 || !l3);
+ if (!l3)
+ return NULL;
+
+ BUG_ON(ac->avail > 0);
spin_lock(&l3->list_lock);

/* See if we can refill from the shared array */
@@ -3224,7 +3227,7 @@ static void *alternate_node_alloc(struct
nid_alloc = cpuset_mem_spread_node();
else if (current->mempolicy)
nid_alloc = slab_node(current->mempolicy);
- if (nid_alloc != nid_here)
+ if (nid_alloc != nid_here && node_state(nid_alloc, N_NORMAL_MEMORY))
return ____cache_alloc_node(cachep, flags, nid_alloc);
return NULL;
}
@@ -3439,8 +3442,14 @@ __do_cache_alloc(struct kmem_cache *cach
* We may just have run out of memory on the local node.
* ____cache_alloc_node() knows how to locate memory on other nodes
*/
- if (!objp)
- objp = ____cache_alloc_node(cache, flags, numa_node_id());
+ if (!objp) {
+ int node_id = numa_node_id();
+ if (likely(cache->nodelists[node_id])) /* fast path */
+ objp = ____cache_alloc_node(cache, flags, node_id);
+ else /* this function can do good fallback */
+ objp = __cache_alloc_node(cache, flags, node_id,
+ __builtin_return_address(0));
+ }

out:
return objp;