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Subject[PATCH 3/6] nommu: find vma using the sorted vma list
Date
Now we have the sorted vma list, use it in the find_vma[_exact]()
rather than doing linear search on the rb-tree.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
mm/nommu.c | 12 ++++--------
1 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/mm/nommu.c b/mm/nommu.c
index a6a073f0745a..6c5a13b507b4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -828,17 +828,15 @@ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
{
struct vm_area_struct *vma;
- struct rb_node *n = mm->mm_rb.rb_node;

/* check the cache first */
vma = mm->mmap_cache;
if (vma && vma->vm_start <= addr && vma->vm_end > addr)
return vma;

- /* trawl the tree (there may be multiple mappings in which addr
+ /* trawl the list (there may be multiple mappings in which addr
* resides) */
- for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
- vma = rb_entry(n, struct vm_area_struct, vm_rb);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->vm_start > addr)
return NULL;
if (vma->vm_end > addr) {
@@ -878,7 +876,6 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
unsigned long len)
{
struct vm_area_struct *vma;
- struct rb_node *n = mm->mm_rb.rb_node;
unsigned long end = addr + len;

/* check the cache first */
@@ -886,10 +883,9 @@ static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
if (vma && vma->vm_start == addr && vma->vm_end == end)
return vma;

- /* trawl the tree (there may be multiple mappings in which addr
+ /* trawl the list (there may be multiple mappings in which addr
* resides) */
- for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
- vma = rb_entry(n, struct vm_area_struct, vm_rb);
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->vm_start < addr)
continue;
if (vma->vm_start > addr)
--
1.7.4


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