From db210e70e5f191710a3b1d09f653b44885d397ea Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Thu, 26 Aug 2010 09:41:19 -0500 Subject: [PATCH] Slub: UP bandaid Since the percpu allocator does not provide early allocation in UP mode (only in SMP configurations) use __get_free_page() to improvise a compound page allocation that can be later freed via kfree(). Compound pages will be released when the cpu caches are resized. Acked-by: David Rientjes Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slub.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/mm/slub.c b/mm/slub.c index 4c5a76f505ea..05674aac9294 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2103,8 +2103,24 @@ init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s) static inline int alloc_kmem_cache_cpus(struct kmem_cache *s) { +#ifdef CONFIG_SMP + /* + * Will use reserve that does not require slab operation during + * early boot. + */ BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE < SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu)); +#else + /* + * Special hack for UP mode. allocpercpu() falls back to kmalloc + * operations. So we cannot use that before the slab allocator is up + * Simply get the smallest possible compound page. The page will be + * released via kfree() when the cpu caches are resized later. + */ + if (slab_state < UP) + s->cpu_slab = (__percpu void *)kmalloc_large(PAGE_SIZE << 1, GFP_NOWAIT); + else +#endif s->cpu_slab = alloc_percpu(struct kmem_cache_cpu); -- 2.30.2