From d58275bc96ae933b1b3888af80920dd6b020c505 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 16 Jan 2017 17:10:21 -0500 Subject: [PATCH] radix-tree: Store a pointer to the root in each node Instead of having this mysterious private_data in each radix_tree_node, store a pointer to the root, which can be useful for debugging. This also relieves the mm code from the duty of updating it. Acked-by: Johannes Weiner Signed-off-by: Matthew Wilcox --- include/linux/radix-tree.h | 2 +- lib/radix-tree.c | 14 ++++++++------ mm/workingset.c | 6 ++---- 3 files changed, 11 insertions(+), 11 deletions(-) diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index 2ba0c1f46c84..d250059bbfa4 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -96,7 +96,7 @@ struct radix_tree_node { unsigned char count; /* Total entry count */ unsigned char exceptional; /* Exceptional entry count */ struct radix_tree_node *parent; /* Used when ascending tree */ - void *private_data; /* For tree user */ + struct radix_tree_root *root; /* The tree we belong to */ union { struct list_head private_list; /* For tree user */ struct rcu_head rcu_head; /* Used when freeing node */ diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 66c71312c381..dcb9a2329e65 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -374,6 +374,7 @@ static void ida_dump(struct ida *ida) */ static struct radix_tree_node * radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, + struct radix_tree_root *root, unsigned int shift, unsigned int offset, unsigned int count, unsigned int exceptional) { @@ -419,11 +420,12 @@ radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent, out: BUG_ON(radix_tree_is_internal_node(ret)); if (ret) { - ret->parent = parent; ret->shift = shift; ret->offset = offset; ret->count = count; ret->exceptional = exceptional; + ret->parent = parent; + ret->root = root; } return ret; } @@ -631,7 +633,7 @@ static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp, do { struct radix_tree_node *node = radix_tree_node_alloc(gfp, NULL, - shift, 0, 1, 0); + root, shift, 0, 1, 0); if (!node) return -ENOMEM; @@ -828,7 +830,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, shift -= RADIX_TREE_MAP_SHIFT; if (child == NULL) { /* Have to add a child node. */ - child = radix_tree_node_alloc(gfp, node, shift, + child = radix_tree_node_alloc(gfp, node, root, shift, offset, 0, 0); if (!child) return -ENOMEM; @@ -1330,7 +1332,7 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index, for (;;) { if (node->shift > order) { - child = radix_tree_node_alloc(gfp, node, + child = radix_tree_node_alloc(gfp, node, root, node->shift - RADIX_TREE_MAP_SHIFT, offset, 0, 0); if (!child) @@ -2152,8 +2154,8 @@ void **idr_get_free(struct radix_tree_root *root, shift -= RADIX_TREE_MAP_SHIFT; if (child == NULL) { /* Have to add a child node. */ - child = radix_tree_node_alloc(gfp, node, shift, offset, - 0, 0); + child = radix_tree_node_alloc(gfp, node, root, shift, + offset, 0, 0); if (!child) return ERR_PTR(-ENOMEM); all_tag_set(child, IDR_FREE); diff --git a/mm/workingset.c b/mm/workingset.c index abb58ffa3c64..80c913c89f11 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -354,10 +354,8 @@ void workingset_update_node(struct radix_tree_node *node, void *private) * as node->private_list is protected by &mapping->tree_lock. */ if (node->count && node->count == node->exceptional) { - if (list_empty(&node->private_list)) { - node->private_data = mapping; + if (list_empty(&node->private_list)) list_lru_add(&shadow_nodes, &node->private_list); - } } else { if (!list_empty(&node->private_list)) list_lru_del(&shadow_nodes, &node->private_list); @@ -435,7 +433,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item, */ node = container_of(item, struct radix_tree_node, private_list); - mapping = node->private_data; + mapping = container_of(node->root, struct address_space, page_tree); /* Coming from the list, invert the lock order */ if (!spin_trylock(&mapping->tree_lock)) {