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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-20 16:24:55 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-26 16:41:44 -0700
commit378776c287c66b32ff9a62c34a9715f702dc336e (patch)
treec259512f7f1a92343e1122cc10b81d97adc32431 /mm
parentd1a2ec482cff1d98c366a40b717dfd95a1a0fac5 (diff)
mm: make the vma list be doubly linked
commit 297c5eee372478fc32fec5fe8eed711eedb13f3d upstream. It's a really simple list, and several of the users want to go backwards in it to find the previous vma. So rather than have to look up the previous entry with 'find_vma_prev()' or something similar, just make it doubly linked instead. Tested-by: Ian Campbell <ijc@hellion.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
-rw-r--r--mm/mmap.c21
-rw-r--r--mm/nommu.c7
2 files changed, 22 insertions, 6 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index ae197468b352..b309c75b497a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -389,17 +389,23 @@ static inline void
__vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node *rb_parent)
{
+ struct vm_area_struct *next;
+
+ vma->vm_prev = prev;
if (prev) {
- vma->vm_next = prev->vm_next;
+ next = prev->vm_next;
prev->vm_next = vma;
} else {
mm->mmap = vma;
if (rb_parent)
- vma->vm_next = rb_entry(rb_parent,
+ next = rb_entry(rb_parent,
struct vm_area_struct, vm_rb);
else
- vma->vm_next = NULL;
+ next = NULL;
}
+ vma->vm_next = next;
+ if (next)
+ next->vm_prev = vma;
}
void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
@@ -487,7 +493,11 @@ static inline void
__vma_unlink(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev)
{
- prev->vm_next = vma->vm_next;
+ struct vm_area_struct *next = vma->vm_next;
+
+ prev->vm_next = next;
+ if (next)
+ next->vm_prev = prev;
rb_erase(&vma->vm_rb, &mm->mm_rb);
if (mm->mmap_cache == vma)
mm->mmap_cache = prev;
@@ -1798,6 +1808,7 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr;
insertion_point = (prev ? &prev->vm_next : &mm->mmap);
+ vma->vm_prev = NULL;
do {
rb_erase(&vma->vm_rb, &mm->mm_rb);
mm->map_count--;
@@ -1805,6 +1816,8 @@ detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
vma = vma->vm_next;
} while (vma && vma->vm_start < end);
*insertion_point = vma;
+ if (vma)
+ vma->vm_prev = prev;
tail_vma->vm_next = NULL;
if (mm->unmap_area == arch_unmap_area)
addr = prev ? prev->vm_end : mm->mmap_base;
diff --git a/mm/nommu.c b/mm/nommu.c
index 9876fa0c3ad3..ebb3154d84e4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -608,7 +608,7 @@ static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
*/
static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
{
- struct vm_area_struct *pvma, **pp;
+ struct vm_area_struct *pvma, **pp, *next;
struct address_space *mapping;
struct rb_node **p, *parent;
@@ -668,8 +668,11 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
break;
}
- vma->vm_next = *pp;
+ next = *pp;
*pp = vma;
+ vma->vm_next = next;
+ if (next)
+ next->vm_prev = vma;
}
/*