forked from mirrors/linux
6b2dbba8b6
Implement an interval tree as a replacement for the VMA prio_tree. The algorithms are similar to lib/interval_tree.c; however that code can't be directly reused as the interval endpoints are not explicitly stored in the VMA. So instead, the common algorithm is moved into a template and the details (node type, how to get interval endpoints from the node, etc) are filled in using the C preprocessor. Once the interval tree functions are available, using them as a replacement to the VMA prio tree is a relatively simple, mechanical job. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
61 lines
1.8 KiB
C
61 lines
1.8 KiB
C
/*
|
|
* mm/interval_tree.c - interval tree for mapping->i_mmap
|
|
*
|
|
* Copyright (C) 2012, Michel Lespinasse <walken@google.com>
|
|
*
|
|
* This file is released under the GPL v2.
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/fs.h>
|
|
|
|
#define ITSTRUCT struct vm_area_struct
|
|
#define ITRB shared.linear.rb
|
|
#define ITTYPE unsigned long
|
|
#define ITSUBTREE shared.linear.rb_subtree_last
|
|
#define ITSTART(n) ((n)->vm_pgoff)
|
|
#define ITLAST(n) ((n)->vm_pgoff + \
|
|
(((n)->vm_end - (n)->vm_start) >> PAGE_SHIFT) - 1)
|
|
#define ITSTATIC
|
|
#define ITPREFIX vma_interval_tree
|
|
|
|
#include <linux/interval_tree_tmpl.h>
|
|
|
|
/* Insert old immediately after vma in the interval tree */
|
|
void vma_interval_tree_add(struct vm_area_struct *vma,
|
|
struct vm_area_struct *old,
|
|
struct address_space *mapping)
|
|
{
|
|
struct rb_node **link;
|
|
struct vm_area_struct *parent;
|
|
unsigned long last;
|
|
|
|
if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
|
|
list_add(&vma->shared.nonlinear, &old->shared.nonlinear);
|
|
return;
|
|
}
|
|
|
|
last = ITLAST(vma);
|
|
|
|
if (!old->shared.linear.rb.rb_right) {
|
|
parent = old;
|
|
link = &old->shared.linear.rb.rb_right;
|
|
} else {
|
|
parent = rb_entry(old->shared.linear.rb.rb_right,
|
|
struct vm_area_struct, shared.linear.rb);
|
|
if (parent->shared.linear.rb_subtree_last < last)
|
|
parent->shared.linear.rb_subtree_last = last;
|
|
while (parent->shared.linear.rb.rb_left) {
|
|
parent = rb_entry(parent->shared.linear.rb.rb_left,
|
|
struct vm_area_struct, shared.linear.rb);
|
|
if (parent->shared.linear.rb_subtree_last < last)
|
|
parent->shared.linear.rb_subtree_last = last;
|
|
}
|
|
link = &parent->shared.linear.rb.rb_left;
|
|
}
|
|
|
|
vma->shared.linear.rb_subtree_last = last;
|
|
rb_link_node(&vma->shared.linear.rb, &parent->shared.linear.rb, link);
|
|
rb_insert_augmented(&vma->shared.linear.rb, &mapping->i_mmap,
|
|
&vma_interval_tree_augment_callbacks);
|
|
}
|