ksm: add cond_resched() to the rmap_walks

While at it add it to the file and anon walks too.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Petr Holasek <pholasek@redhat.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 6 insertions, 0 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index 7ee101eaacdf..e87dec7ba950 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1914,9 +1914,11 @@ again:
                 struct anon_vma_chain *vmac;
                 struct vm_area_struct *vma;
 
+                cond_resched();
                 anon_vma_lock_read(anon_vma);
                 anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
                                                0, ULONG_MAX) {
+                        cond_resched();
                         vma = vmac->vma;
                         if (rmap_item->address < vma->vm_start ||
                             rmap_item->address >= vma->vm_end)
diff --git a/mm/rmap.c b/mm/rmap.c
index d40e7aefb888..78a692827a63 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1609,6 +1609,8 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
                 struct vm_area_struct *vma = avc->vma;
                 unsigned long address = vma_address(page, vma);
 
+                cond_resched();
+
                 if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
                         continue;
 
@@ -1658,6 +1660,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
         vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);
 
+                cond_resched();
+
                 if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
                         continue;