mm: replace vma prio_tree with an interval tree
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>
diff --git a/lib/prio_tree.c b/lib/prio_tree.c
index 4e0d2ed..bba3714 100644
--- a/lib/prio_tree.c
+++ b/lib/prio_tree.c
@@ -44,27 +44,12 @@
* The following macros are used for implementing prio_tree for i_mmap
*/
-#define RADIX_INDEX(vma) ((vma)->vm_pgoff)
-#define VMA_SIZE(vma) (((vma)->vm_end - (vma)->vm_start) >> PAGE_SHIFT)
-/* avoid overflow */
-#define HEAP_INDEX(vma) ((vma)->vm_pgoff + (VMA_SIZE(vma) - 1))
-
-
static void get_index(const struct prio_tree_root *root,
const struct prio_tree_node *node,
unsigned long *radix, unsigned long *heap)
{
- if (root->raw) {
- struct vm_area_struct *vma = prio_tree_entry(
- node, struct vm_area_struct, shared.prio_tree_node);
-
- *radix = RADIX_INDEX(vma);
- *heap = HEAP_INDEX(vma);
- }
- else {
- *radix = node->start;
- *heap = node->last;
- }
+ *radix = node->start;
+ *heap = node->last;
}
static unsigned long index_bits_to_maxindex[BITS_PER_LONG];