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authorMatthew Wilcox <mawilcox@microsoft.com>2017-01-17 01:10:21 +0300
committerMatthew Wilcox <mawilcox@microsoft.com>2017-02-14 05:44:05 +0300
commitd58275bc96ae933b1b3888af80920dd6b020c505 (patch)
treee1acf252dc43eeb1d65e4f715b0a1d52b1b4af09
parent1293d5c5f54d5118fbb34fc94e01ba02fcd25fc1 (diff)
downloadlinux-d58275bc96ae933b1b3888af80920dd6b020c505.tar.xz
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 <hannes@cmpxchg.org> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
-rw-r--r--include/linux/radix-tree.h2
-rw-r--r--lib/radix-tree.c14
-rw-r--r--mm/workingset.c6
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)) {