[PATCH 1/5] mm/vmalloc: Make link_va()/unlink_va() common to different rb_root

Uladzislau Rezki (Sony)
2022-06-07T09:35:56Z

Currently link_va() and unlik_va(), in order to figure out a tree
type, compares a passed root value with a global free_vmap_area_root
variable to distinguish the augmented rb-tree from a regular one. It
is hard coded since such functions can manipulate only with specific
"free_vmap_area_root" tree that represents a global free vmap space.

Make it common by introducing "_augment" versions of both internal
functions, so it is possible to deal with different trees.

There is no functional change as a result of this patch.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
mm/vmalloc.c | 60 +++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 48 insertions(+), 12 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index be8ed06804a5..0102d6d5fcdf 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -911,8 +911,9 @@ get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
}

static __always_inline void
-link_va(struct vmap_area *va, struct rb_root *root,
- struct rb_node *parent, struct rb_node **link, struct list_head *head)
+__link_va(struct vmap_area *va, struct rb_root *root,
+ struct rb_node *parent, struct rb_node **link,
+ struct list_head *head, bool augment)
{
/*
* VA is still not in the list, but we can
@@ -926,7 +927,7 @@ link_va(struct vmap_area *va, struct rb_root *root,

/* Insert to the rb-tree */
rb_link_node(&va->rb_node, parent, link);
- if (root == &free_vmap_area_root) {
+ if (augment) {
/*
* Some explanation here. Just perform simple insertion
* to the tree. We do not set va->subtree_max_size to
@@ -950,12 +951,28 @@ link_va(struct vmap_area *va, struct rb_root *root,
}

static __always_inline void
-unlink_va(struct vmap_area *va, struct rb_root *root)
+link_va(struct vmap_area *va, struct rb_root *root,
+ struct rb_node *parent, struct rb_node **link,
+ struct list_head *head)
+{
+ __link_va(va, root, parent, link, head, false);
+}
+
+static __always_inline void
+link_va_augment(struct vmap_area *va, struct rb_root *root,
+ struct rb_node *parent, struct rb_node **link,
+ struct list_head *head)
+{
+ __link_va(va, root, parent, link, head, true);
+}
+
+static __always_inline void
+__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
{
if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
return;

- if (root == &free_vmap_area_root)
+ if (augment)
rb_erase_augmented(&va->rb_node,
root, &free_vmap_area_rb_augment_cb);
else
@@ -965,6 +982,18 @@ unlink_va(struct vmap_area *va, struct rb_root *root)
RB_CLEAR_NODE(&va->rb_node);
}

+static __always_inline void
+unlink_va(struct vmap_area *va, struct rb_root *root)
+{
+ __unlink_va(va, root, false);
+}
+
+static __always_inline void
+unlink_va_augment(struct vmap_area *va, struct rb_root *root)
+{
+ __unlink_va(va, root, true);
+}
+
#if DEBUG_AUGMENT_PROPAGATE_CHECK
/*
* Gets called when remove the node and rotate.
@@ -1060,7 +1089,7 @@ insert_vmap_area_augment(struct vmap_area *va,
link = find_va_links(va, root, NULL, &parent);

if (link) {
- link_va(va, root, parent, link, head);
+ link_va_augment(va, root, parent, link, head);
augment_tree_propagate_from(va);
}
}
@@ -1077,8 +1106,8 @@ insert_vmap_area_augment(struct vmap_area *va,
* ongoing.
*/
static __always_inline struct vmap_area *
-merge_or_add_vmap_area(struct vmap_area *va,
- struct rb_root *root, struct list_head *head)
+__merge_or_add_vmap_area(struct vmap_area *va,
+ struct rb_root *root, struct list_head *head, bool augment)
{
struct vmap_area *sibling;
struct list_head *next;
@@ -1140,7 +1169,7 @@ merge_or_add_vmap_area(struct vmap_area *va,
* "normalized" because of rotation operations.
*/
if (merged)
- unlink_va(va, root);
+ __unlink_va(va, root, augment);

sibling->va_end = va->va_end;

@@ -1155,16 +1184,23 @@ merge_or_add_vmap_area(struct vmap_area *va,

insert:
if (!merged)
- link_va(va, root, parent, link, head);
+ __link_va(va, root, parent, link, head, augment);

return va;
}

+static __always_inline struct vmap_area *
+merge_or_add_vmap_area(struct vmap_area *va,
+ struct rb_root *root, struct list_head *head)
+{
+ return __merge_or_add_vmap_area(va, root, head, false);
+}
+
static __always_inline struct vmap_area *
merge_or_add_vmap_area_augment(struct vmap_area *va,
struct rb_root *root, struct list_head *head)
{
- va = merge_or_add_vmap_area(va, root, head);
+ va = __merge_or_add_vmap_area(va, root, head, true);
if (va)
augment_tree_propagate_from(va);

@@ -1348,7 +1384,7 @@ adjust_va_to_fit_type(struct vmap_area *va,
* V NVA V
* |---------------|
*/
- unlink_va(va, &free_vmap_area_root);
+ unlink_va_augment(va, &free_vmap_area_root);
kmem_cache_free(vmap_area_cachep, va);
} else if (type == LE_FIT_TYPE) {
/*
--
2.30.2