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mm: SLAB Out-of-memory diagnostics

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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>
This commit is contained in:
Rafael Aquini 2012-03-09 17:27:27 -03:00 committed by Pekka Enberg
parent a8203725df
commit 8bdec192b4
1 changed files with 50 additions and 1 deletions
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51
mm/slab.c
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@ -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)