mm/ksm: Use maple tree iterators instead of vma linked list

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/mm/ksm.c b/mm/ksm.c
index 3fa9bc8a67cf63502e9c75fb7c0e9f1ed65c1149..a751620db4f9cabe673d19e93f06b7827b693894 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -970,11 +970,14 @@ static int unmerge_and_remove_all_rmap_items(void)
                                                struct mm_slot, mm_list);
        spin_unlock(&ksm_mmlist_lock);
 
-       for (mm_slot = ksm_scan.mm_slot;
-                       mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
+       for (mm_slot = ksm_scan.mm_slot; mm_slot != &ksm_mm_head;
+            mm_slot = ksm_scan.mm_slot) {
+               MA_STATE(mas, &mm_slot->mm->mm_mt, 0, 0);
+
                mm = mm_slot->mm;
                mmap_read_lock(mm);
-               for (vma = mm->mmap; vma; vma = vma->vm_next) {
+               rcu_read_lock();
+               mas_for_each(&mas, vma, ULONG_MAX) {
                        if (ksm_test_exit(mm))
                                break;
                        if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
@@ -986,6 +989,7 @@ static int unmerge_and_remove_all_rmap_items(void)
                }
 
                remove_trailing_rmap_items(&mm_slot->rmap_list);
+               rcu_read_unlock();
                mmap_read_unlock(mm);
 
                spin_lock(&ksm_mmlist_lock);
@@ -1009,6 +1013,7 @@ static int unmerge_and_remove_all_rmap_items(void)
        return 0;
 
 error:
+       rcu_read_unlock();
        mmap_read_unlock(mm);
        spin_lock(&ksm_mmlist_lock);
        ksm_scan.mm_slot = &ksm_mm_head;
@@ -2223,6 +2228,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
        struct vm_area_struct *vma;
        struct rmap_item *rmap_item;
        int nid;
+       MA_STATE(mas, NULL, 0, 0);
 
        if (list_empty(&ksm_mm_head.mm_list))
                return NULL;
@@ -2280,13 +2286,15 @@ next_mm:
        }
 
        mm = slot->mm;
+       mas.tree = &mm->mm_mt;
+
        mmap_read_lock(mm);
+       rcu_read_lock();
        if (ksm_test_exit(mm))
-               vma = NULL;
-       else
-               vma = find_vma(mm, ksm_scan.address);
+               goto no_vmas;
 
-       for (; vma; vma = vma->vm_next) {
+       mas_set(&mas, ksm_scan.address);
+       mas_for_each(&mas, vma, ULONG_MAX) {
                if (!(vma->vm_flags & VM_MERGEABLE))
                        continue;
                if (ksm_scan.address < vma->vm_start)
@@ -2314,6 +2322,7 @@ next_mm:
                                        ksm_scan.address += PAGE_SIZE;
                                } else
                                        put_page(*page);
+                               rcu_read_unlock();
                                mmap_read_unlock(mm);
                                return rmap_item;
                        }
@@ -2324,6 +2333,7 @@ next_mm:
        }
 
        if (ksm_test_exit(mm)) {
+no_vmas:
                ksm_scan.address = 0;
                ksm_scan.rmap_list = &slot->rmap_list;
        }
@@ -2352,9 +2362,11 @@ next_mm:
 
                free_mm_slot(slot);
                clear_bit(MMF_VM_MERGEABLE, &mm->flags);
+               rcu_read_unlock();
                mmap_read_unlock(mm);
                mmdrop(mm);
        } else {
+               rcu_read_unlock();
                mmap_read_unlock(mm);
                /*
                 * mmap_read_unlock(mm) first because after