We need an anon_vma refcount for preemptible anon_vma->lock as well as memory compaction, so move it out into generic code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> --- Index: linux-2.6/include/linux/rmap.h =================================================================== --- linux-2.6.orig/include/linux/rmap.h +++ linux-2.6/include/linux/rmap.h @@ -26,9 +26,7 @@ */ struct anon_vma { spinlock_t lock; /* Serialize access to vma list */ -#ifdef CONFIG_KSM - atomic_t ksm_refcount; -#endif + atomic_t ref; /* * NOTE: the LSB of the head.next is set by * mm_take_all_locks() _after_ taking the above lock. So the @@ -61,26 +59,6 @@ struct anon_vma_chain { }; #ifdef CONFIG_MMU -#ifdef CONFIG_KSM -static inline void ksm_refcount_init(struct anon_vma *anon_vma) -{ - atomic_set(&anon_vma->ksm_refcount, 0); -} - -static inline int ksm_refcount(struct anon_vma *anon_vma) -{ - return atomic_read(&anon_vma->ksm_refcount); -} -#else -static inline void ksm_refcount_init(struct anon_vma *anon_vma) -{ -} - -static inline int ksm_refcount(struct anon_vma *anon_vma) -{ - return 0; -} -#endif /* CONFIG_KSM */ static inline struct anon_vma *page_anon_vma(struct page *page) { Index: linux-2.6/mm/ksm.c =================================================================== --- linux-2.6.orig/mm/ksm.c +++ linux-2.6/mm/ksm.c @@ -318,14 +318,14 @@ static void hold_anon_vma(struct rmap_it struct anon_vma *anon_vma) { rmap_item->anon_vma = anon_vma; - atomic_inc(&anon_vma->ksm_refcount); + atomic_inc(&anon_vma->ref); } static void drop_anon_vma(struct rmap_item *rmap_item) { struct anon_vma *anon_vma = rmap_item->anon_vma; - if (atomic_dec_and_lock(&anon_vma->ksm_refcount, &anon_vma->lock)) { + if (atomic_dec_and_lock(&anon_vma->ref, &anon_vma->lock)) { int empty = list_empty(&anon_vma->head); spin_unlock(&anon_vma->lock); if (empty) Index: linux-2.6/mm/rmap.c =================================================================== --- linux-2.6.orig/mm/rmap.c +++ linux-2.6/mm/rmap.c @@ -248,7 +248,7 @@ static void anon_vma_unlink(struct anon_ list_del(&anon_vma_chain->same_anon_vma); /* We must garbage collect the anon_vma if it's empty */ - empty = list_empty(&anon_vma->head) && !ksm_refcount(anon_vma); + empty = list_empty(&anon_vma->head) && !atomic_read(&anon_vma->ref); spin_unlock(&anon_vma->lock); if (empty) @@ -272,7 +272,7 @@ static void anon_vma_ctor(void *data) struct anon_vma *anon_vma = data; spin_lock_init(&anon_vma->lock); - ksm_refcount_init(anon_vma); + atomic_set(&anon_vma->ref, 0); INIT_LIST_HEAD(&anon_vma->head); } -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html