aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/fork.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-20 19:24:55 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-21 11:49:21 -0400
commit297c5eee372478fc32fec5fe8eed711eedb13f3d (patch)
tree18415eae0833ff4767943f985900524d6b1d73f1 /kernel/fork.c
parent36423a5ed5e4ea95ceedb68fad52965033e11639 (diff)
mm: make the vma list be doubly linked
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>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 856eac3ec52e..b7e9d60a675d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -300,7 +300,7 @@ out:
300#ifdef CONFIG_MMU 300#ifdef CONFIG_MMU
301static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) 301static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
302{ 302{
303 struct vm_area_struct *mpnt, *tmp, **pprev; 303 struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
304 struct rb_node **rb_link, *rb_parent; 304 struct rb_node **rb_link, *rb_parent;
305 int retval; 305 int retval;
306 unsigned long charge; 306 unsigned long charge;
@@ -328,6 +328,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
328 if (retval) 328 if (retval)
329 goto out; 329 goto out;
330 330
331 prev = NULL;
331 for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) { 332 for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
332 struct file *file; 333 struct file *file;
333 334
@@ -359,7 +360,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
359 goto fail_nomem_anon_vma_fork; 360 goto fail_nomem_anon_vma_fork;
360 tmp->vm_flags &= ~VM_LOCKED; 361 tmp->vm_flags &= ~VM_LOCKED;
361 tmp->vm_mm = mm; 362 tmp->vm_mm = mm;
362 tmp->vm_next = NULL; 363 tmp->vm_next = tmp->vm_prev = NULL;
363 file = tmp->vm_file; 364 file = tmp->vm_file;
364 if (file) { 365 if (file) {
365 struct inode *inode = file->f_path.dentry->d_inode; 366 struct inode *inode = file->f_path.dentry->d_inode;
@@ -392,6 +393,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
392 */ 393 */
393 *pprev = tmp; 394 *pprev = tmp;
394 pprev = &tmp->vm_next; 395 pprev = &tmp->vm_next;
396 tmp->vm_prev = prev;
397 prev = tmp;
395 398
396 __vma_link_rb(mm, tmp, rb_link, rb_parent); 399 __vma_link_rb(mm, tmp, rb_link, rb_parent);
397 rb_link = &tmp->vm_rb.rb_right; 400 rb_link = &tmp->vm_rb.rb_right;