Commit 8eb510db authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony) Committed by Andrew Morton
Browse files

mm/vmalloc: make link_va()/unlink_va() common to different rb_root 

Patch series "Reduce a vmalloc internal lock contention preparation work".

This small serias is preparation work to implement per-cpu vmalloc
allocation in order to reduce a high internal lock contention.  This
series does not introduce any functional changes, it is only about
preparation.


This patch (of 5):

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.

Link: https://lkml.kernel.org/r/20220607093449.3100-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20220607093449.3100-2-urezki@gmail.com


Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: default avatarBaoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent bbf535fd

mm/vmalloc.c

+48 −12
Original line number Diff line number Diff line
@@ -910,8 +910,9 @@ 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
@@ -925,7 +926,7 @@ 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
@@ -949,12 +950,28 @@ 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
@@ -964,6 +981,18 @@ 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.
@@ -1059,7 +1088,7 @@ 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);

	}

}
@@ -1076,8 +1105,8 @@ 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;
@@ -1139,7 +1168,7 @@ 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;
@@ -1154,16 +1183,23 @@ 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);
@@ -1347,7 +1383,7 @@ 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) {

		/*