The normal code pattern used in the kernel is: get/put. Reviewed-by: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Signed-off-by: Peter Zijlstra --- include/linux/rmap.h | 4 ++-- mm/ksm.c | 23 +++++------------------ mm/migrate.c | 4 ++-- mm/rmap.c | 4 ++-- 4 files changed, 11 insertions(+), 24 deletions(-) Index: linux-2.6/include/linux/rmap.h =================================================================== --- linux-2.6.orig/include/linux/rmap.h +++ linux-2.6/include/linux/rmap.h @@ -87,7 +87,7 @@ static inline void get_anon_vma(struct a atomic_inc(&anon_vma->external_refcount); } -void drop_anon_vma(struct anon_vma *); +void put_anon_vma(struct anon_vma *); #else static inline void anonvma_external_refcount_init(struct anon_vma *anon_vma) { @@ -102,7 +102,7 @@ static inline void get_anon_vma(struct a { } -static inline void drop_anon_vma(struct anon_vma *anon_vma) +static inline void put_anon_vma(struct anon_vma *anon_vma) { } #endif /* CONFIG_KSM */ Index: linux-2.6/mm/ksm.c =================================================================== --- linux-2.6.orig/mm/ksm.c +++ linux-2.6/mm/ksm.c @@ -301,20 +301,6 @@ static inline int in_stable_tree(struct return rmap_item->address & STABLE_FLAG; } -static void hold_anon_vma(struct rmap_item *rmap_item, - struct anon_vma *anon_vma) -{ - rmap_item->anon_vma = anon_vma; - get_anon_vma(anon_vma); -} - -static void ksm_drop_anon_vma(struct rmap_item *rmap_item) -{ - struct anon_vma *anon_vma = rmap_item->anon_vma; - - drop_anon_vma(anon_vma); -} - /* * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's * page tables after it has passed through ksm_exit() - which, if necessary, @@ -397,7 +383,7 @@ static void break_cow(struct rmap_item * * It is not an accident that whenever we want to break COW * to undo, we also need to drop a reference to the anon_vma. */ - ksm_drop_anon_vma(rmap_item); + put_anon_vma(rmap_item->anon_vma); down_read(&mm->mmap_sem); if (ksm_test_exit(mm)) @@ -466,7 +452,7 @@ static void remove_node_from_stable_tree ksm_pages_sharing--; else ksm_pages_shared--; - ksm_drop_anon_vma(rmap_item); + put_anon_vma(rmap_item->anon_vma); rmap_item->address &= PAGE_MASK; cond_resched(); } @@ -554,7 +540,7 @@ static void remove_rmap_item_from_tree(s else ksm_pages_shared--; - ksm_drop_anon_vma(rmap_item); + put_anon_vma(rmap_item->anon_vma); rmap_item->address &= PAGE_MASK; } else if (rmap_item->address & UNSTABLE_FLAG) { @@ -949,7 +935,8 @@ static int try_to_merge_with_ksm_page(st goto out; /* Must get reference to anon_vma while still holding mmap_sem */ - hold_anon_vma(rmap_item, vma->anon_vma); + rmap_item->anon_vma = vma->anon_vma; + get_anon_vma(vma->anon_vma); out: up_read(&mm->mmap_sem); return err; Index: linux-2.6/mm/migrate.c =================================================================== --- linux-2.6.orig/mm/migrate.c +++ linux-2.6/mm/migrate.c @@ -764,7 +764,7 @@ static int unmap_and_move(new_page_t get /* Drop an anon_vma reference if we took one */ if (anon_vma) - drop_anon_vma(anon_vma); + put_anon_vma(anon_vma); uncharge: if (!charge) @@ -857,7 +857,7 @@ static int unmap_and_move_huge_page(new_ remove_migration_ptes(hpage, hpage); if (anon_vma) - drop_anon_vma(anon_vma); + put_anon_vma(anon_vma); out: unlock_page(hpage); Index: linux-2.6/mm/rmap.c =================================================================== --- linux-2.6.orig/mm/rmap.c +++ linux-2.6/mm/rmap.c @@ -278,7 +278,7 @@ static void anon_vma_unlink(struct anon_ if (empty) { /* We no longer need the root anon_vma */ if (anon_vma->root != anon_vma) - drop_anon_vma(anon_vma->root); + put_anon_vma(anon_vma->root); anon_vma_free(anon_vma); } } @@ -1489,7 +1489,7 @@ int try_to_munlock(struct page *page) * we know we are the last user, nobody else can get a reference and we * can do the freeing without the lock. */ -void drop_anon_vma(struct anon_vma *anon_vma) +void put_anon_vma(struct anon_vma *anon_vma) { BUG_ON(atomic_read(&anon_vma->external_refcount) <= 0); if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->root->lock)) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/