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

Baoquan He
2022-06-08T06:44:00Z

On 06/07/22 at 11:34am, Uladzislau Rezki (Sony) wrote:
> 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.

Patch looks good to me. Looking forward to seeing the later per-cpu
vmalloc allocation patches.

Reviewed-by: Baoquan He <bhe@redhat.com>

>
> 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
>
>