[PATCH v4 09/13] memcg: cleanup preparation for page table walk

Naoya Horiguchi
2014-07-01T17:11:33Z

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.

ChangeLog v4:
- use walk_page_range() instead of walk_page_vma() with for loop.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
mm/memcontrol.c | 49 ++++++++++++++++---------------------------------
1 file changed, 16 insertions(+), 33 deletions(-)

diff --git v3.16-rc3.orig/mm/memcontrol.c v3.16-rc3/mm/memcontrol.c
index a2c7bcb0e6eb..6c075113c363 100644
--- v3.16-rc3.orig/mm/memcontrol.c
+++ v3.16-rc3/mm/memcontrol.c
@@ -6654,7 +6654,7 @@ 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;

@@ -6680,20 +6680,13 @@ 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;
@@ -6832,7 +6825,7 @@ 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;
@@ -6932,7 +6925,10 @@ 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();
retry:
@@ -6948,24 +6944,11 @@ static void mem_cgroup_move_charge(struct mm_struct *mm)
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);
}

--
1.9.3