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, so this is only useful to diagnose allocator bugs. 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 <[email protected]> --- 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 --- a/mm/slab.c +++ b/mm/slab.c @@ -1621,11 +1621,17 @@ __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; + if (gfpflags & __GFP_NOWARN) + return; + if (!printk_ratelimit()) + return; + printk(KERN_WARNING "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", nodeid, gfpflags); @@ -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 --- a/mm/slub.c +++ b/mm/slub.c @@ -2152,8 +2152,14 @@ 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 int node; + if (gfpflags & __GFP_NOWARN) + return; + if (!printk_ratelimit()) + return; + printk(KERN_WARNING "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", nid, gfpflags); @@ -2182,6 +2188,7 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) " 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, @@ -2360,9 +2367,7 @@ 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
