From d6eeda114389cbe5798a7833500dbf6e80607959 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 14 May 2014 10:01:30 +1000 Subject: [PATCH] mm, slab: suppress out of memory warning unless debug is enabled When the slab or slub allocators cannot allocate additional slab pages, they emit diagnostic information to the kernel log such as current number of slabs, number of objects, active objects, etc. This is always coupled with a page allocation failure warning since it is controlled by !__GFP_NOWARN. Suppress this out of memory warning if the allocator is configured without debug supported. The page allocation failure warning will indicate it is a failed slab allocation, the order, and the gfp mask, so this is only useful to diagnose allocator issues. Since CONFIG_SLUB_DEBUG is already enabled by default for the slub allocator, there is no functional change with this patch. If debug is disabled, however, the warnings are now suppressed. Signed-off-by: David Rientjes Cc: Pekka Enberg Acked-by: Christoph Lameter Signed-off-by: Andrew Morton --- mm/slab.c | 10 ++++++++-- mm/slub.c | 11 ++++++++--- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 19d92181ce24..5c846d25c17d 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1621,10 +1621,16 @@ __initcall(cpucache_init); static noinline void slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) { +#if DEBUG struct kmem_cache_node *n; struct page *page; unsigned long flags; int node; + static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) + return; printk(KERN_WARNING "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", @@ -1662,6 +1668,7 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) node, active_slabs, num_slabs, active_objs, num_objs, free_objects); } +#endif } /* @@ -1683,8 +1690,7 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); if (!page) { - if (!(flags & __GFP_NOWARN) && printk_ratelimit()) - slab_out_of_memory(cachep, flags, nodeid); + slab_out_of_memory(cachep, flags, nodeid); return NULL; } diff --git a/mm/slub.c b/mm/slub.c index de99d500af6c..269d049108e3 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2150,8 +2150,14 @@ static inline unsigned long node_nr_objs(struct kmem_cache_node *n) static noinline void slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) { +#ifdef CONFIG_SLUB_DEBUG + static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); int node; + if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slub_oom_rs)) + return; + pr_warn("SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", nid, gfpflags); pr_warn(" cache: %s, object size: %d, buffer size: %d, default order: %d, min order: %d\n", @@ -2178,6 +2184,7 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) pr_warn(" node %d: slabs: %ld, objs: %ld, free: %ld\n", node, nr_slabs, nr_objs, nr_free); } +#endif } static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags, @@ -2356,9 +2363,7 @@ new_slab: freelist = new_slab_objects(s, gfpflags, node, &c); if (unlikely(!freelist)) { - if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) - slab_out_of_memory(s, gfpflags, node); - + slab_out_of_memory(s, gfpflags, node); local_irq_restore(flags); return NULL; } -- 2.39.5