memcg: cleanup preparation for page table walk

pagewalk.c can handle vma in itself, so we don't have to pass vma via
walk->private.  And both of mem_cgroup_count_precharge() and
mem_cgroup_move_charge() do for each vma loop themselves, but now it's
done in pagewalk.c, so let's clean up them.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c7a9cb627180cac1a880d745cef1b19ea8f152b6..095c1f96fbecf34c13ea9762140337fdbf316421 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4839,7 +4839,7 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
                                        unsigned long addr, unsigned long end,
                                        struct mm_walk *walk)
 {
-       struct vm_area_struct *vma = walk->private;
+       struct vm_area_struct *vma = walk->vma;
        pte_t *pte;
        spinlock_t *ptl;
 
@@ -4865,20 +4865,13 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
 static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
 {
        unsigned long precharge;
-       struct vm_area_struct *vma;
 
+       struct mm_walk mem_cgroup_count_precharge_walk = {
+               .pmd_entry = mem_cgroup_count_precharge_pte_range,
+               .mm = mm,
+       };
        down_read(&mm->mmap_sem);
-       for (vma = mm->mmap; vma; vma = vma->vm_next) {
-               struct mm_walk mem_cgroup_count_precharge_walk = {
-                       .pmd_entry = mem_cgroup_count_precharge_pte_range,
-                       .mm = mm,
-                       .private = vma,
-               };
-               if (is_vm_hugetlb_page(vma))
-                       continue;
-               walk_page_range(vma->vm_start, vma->vm_end,
-                                       &mem_cgroup_count_precharge_walk);
-       }
+       walk_page_range(0, ~0UL, &mem_cgroup_count_precharge_walk);
        up_read(&mm->mmap_sem);
 
        precharge = mc.precharge;
@@ -5011,7 +5004,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
                                struct mm_walk *walk)
 {
        int ret = 0;
-       struct vm_area_struct *vma = walk->private;
+       struct vm_area_struct *vma = walk->vma;
        pte_t *pte;
        spinlock_t *ptl;
        enum mc_target_type target_type;
@@ -5107,7 +5100,10 @@ put:                     /* get_mctgt_type() gets the page */
 
 static void mem_cgroup_move_charge(struct mm_struct *mm)
 {
-       struct vm_area_struct *vma;
+       struct mm_walk mem_cgroup_move_charge_walk = {
+               .pmd_entry = mem_cgroup_move_charge_pte_range,
+               .mm = mm,
+       };
 
        lru_add_drain_all();
        /*
@@ -5130,24 +5126,11 @@ retry:
                cond_resched();
                goto retry;
        }
-       for (vma = mm->mmap; vma; vma = vma->vm_next) {
-               int ret;
-               struct mm_walk mem_cgroup_move_charge_walk = {
-                       .pmd_entry = mem_cgroup_move_charge_pte_range,
-                       .mm = mm,
-                       .private = vma,
-               };
-               if (is_vm_hugetlb_page(vma))
-                       continue;
-               ret = walk_page_range(vma->vm_start, vma->vm_end,
-                                               &mem_cgroup_move_charge_walk);
-               if (ret)
-                       /*
-                        * means we have consumed all precharges and failed in
-                        * doing additional charge. Just abandon here.
-                        */
-                       break;
-       }
+       /*
+        * When we have consumed all precharges and failed in doing
+        * additional charge, the page walk just aborts.
+        */
+       walk_page_range(0, ~0UL, &mem_cgroup_move_charge_walk);
        up_read(&mm->mmap_sem);
        atomic_dec(&mc.from->moving_account);
 }