From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx129.postini.com [74.125.245.129]) by kanga.kvack.org (Postfix) with SMTP id 6519E6B0044 for ; Fri, 9 Mar 2012 15:29:17 -0500 (EST) Date: Fri, 9 Mar 2012 17:27:27 -0300 From: Rafael Aquini Subject: [PATCH v3] mm: SLAB Out-of-memory diagnostics Message-ID: <20120309202722.GA10323@x61.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Randy Dunlap , Christoph Lameter , Pekka Enberg , Matt Mackall , Rik van Riel , Josef Bacik , David Rientjes , Cong Wang 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: 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 Acked-by: Rik van Riel --- v2: * drop the sysctl knob to override __GFP_NOWARN allocation flag (Pekka, David) v3: * adjust the print output to match slub's warning printout (WANG Cong) mm/slab.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 50 insertions(+), 1 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index f0bd785..cda1ff6 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) -- 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org