[PATCH] nr_slab accounting fix

From: Manfred Spraul <manfred@colorfullife.com>

if alloc_slabmgmt fails, then kmem_freepages() calls sub_page_state(),
altough nr_slab was not yet increased.  The attached patch fixes that by
moving the inc_page_state into kmem_getpages().

include/linux/page-flags.h

@@ -133,6 +133,7 @@ extern void get_full_page_state(struct page_state *ret);
 
 #define inc_page_state(member)	mod_page_state(member, 1UL)
 #define dec_page_state(member)	mod_page_state(member, 0UL - 1)
+#define add_page_state(member,delta) mod_page_state(member, (delta))
 #define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
 
 

mm/slab.c

@@ -812,6 +812,7 @@ static inline void *kmem_getpages(kmem_cache_t *cachep, unsigned long flags)
 
 		if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
 			atomic_add(i, &slab_reclaim_pages);
+		add_page_state(nr_slab, i);
 		while (i--) {
 			SetPageSlab(page);
 			page++;
@@ -1608,7 +1609,6 @@ static int cache_grow (kmem_cache_t * cachep, int flags)
 	do {
 		SET_PAGE_CACHE(page, cachep);
 		SET_PAGE_SLAB(page, slabp);
-		inc_page_state(nr_slab);
 		page++;
 	} while (--i);