From 42c8c99cd891184bf4bcf6f09d62c54e42599453 Mon Sep 17 00:00:00 2001 From: Zhao Jin Date: Sat, 27 Aug 2011 00:26:17 +0800 Subject: slab, cleanup: remove unneeded return The procedure ends right after the if-statement, so remove ``return''. Also move the last common statement outside. Signed-off-by: Zhao Jin Acked-by: David Rientjes Acked-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slab.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index f0bd7857ab3..806a754fad8 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3693,13 +3693,12 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp, if (likely(ac->avail < ac->limit)) { STATS_INC_FREEHIT(cachep); - ac->entry[ac->avail++] = objp; - return; } else { STATS_INC_FREEMISS(cachep); cache_flusharray(cachep, ac); - ac->entry[ac->avail++] = objp; } + + ac->entry[ac->avail++] = objp; } /** -- cgit v1.2.3 From 8bdec192b40cf7f7eec170b317c76089eb5eeddb Mon Sep 17 00:00:00 2001 From: Rafael Aquini Date: Fri, 9 Mar 2012 17:27:27 -0300 Subject: 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: 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 Acked-by: David Rientjes Signed-off-by: Pekka Enberg --- mm/slab.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 806a754fad8..67e0e058926 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) -- cgit v1.2.3