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authorRafael Aquini <aquini@redhat.com>2012-03-09 17:27:27 -0300
committerPekka Enberg <penberg@kernel.org>2012-03-10 10:45:17 +0200
commit8bdec192b40cf7f7eec170b317c76089eb5eeddb (patch)
tree78bf7e353438b4ebe26b494e50d26111dc87d0d5 /mm
parenta8203725dfded5c1f79dca3368a4a273e24b59bb (diff)
downloadop-kernel-dev-8bdec192b40cf7f7eec170b317c76089eb5eeddb.zip
op-kernel-dev-8bdec192b40cf7f7eec170b317c76089eb5eeddb.tar.gz
mm: SLAB Out-of-memory diagnostics
Following the example at mm/slub.c, add out-of-memory diagnostics to the SLAB allocator to help on debugging certain OOM conditions. An example print out looks like this: <snip page allocator out-of-memory message> SLAB: Unable to allocate memory on node 0 (gfp=0x11200) cache: bio-0, object size: 192, order: 0 node 0: slabs: 3/3, objs: 60/60, free: 0 Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c51
1 files changed, 50 insertions, 1 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 806a754..67e0e05 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1731,6 +1731,52 @@ static int __init cpucache_init(void)
}
__initcall(cpucache_init);
+static noinline void
+slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
+{
+ struct kmem_list3 *l3;
+ struct slab *slabp;
+ unsigned long flags;
+ int node;
+
+ printk(KERN_WARNING
+ "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
+ nodeid, gfpflags);
+ printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n",
+ cachep->name, cachep->buffer_size, cachep->gfporder);
+
+ for_each_online_node(node) {
+ unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
+ unsigned long active_slabs = 0, num_slabs = 0;
+
+ l3 = cachep->nodelists[node];
+ if (!l3)
+ continue;
+
+ spin_lock_irqsave(&l3->list_lock, flags);
+ list_for_each_entry(slabp, &l3->slabs_full, list) {
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_partial, list) {
+ active_objs += slabp->inuse;
+ active_slabs++;
+ }
+ list_for_each_entry(slabp, &l3->slabs_free, list)
+ num_slabs++;
+
+ free_objects += l3->free_objects;
+ spin_unlock_irqrestore(&l3->list_lock, flags);
+
+ num_slabs += active_slabs;
+ num_objs = num_slabs * cachep->num;
+ printk(KERN_WARNING
+ " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
+ node, active_slabs, num_slabs, active_objs, num_objs,
+ free_objects);
+ }
+}
+
/*
* Interface to system's page allocator. No need to hold the cache-lock.
*
@@ -1757,8 +1803,11 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
flags |= __GFP_RECLAIMABLE;
page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
- if (!page)
+ if (!page) {
+ if (!(flags & __GFP_NOWARN) && printk_ratelimit())
+ slab_out_of_memory(cachep, flags, nodeid);
return NULL;
+ }
nr_pages = (1 << cachep->gfporder);
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
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