[PATCH v2 7/7] memcg: supports movement of surplus hugepages statistics

TSUKADA Koutaro
2018-05-18T04:41:15Z

When the task that charged surplus hugepages moves memory cgroup, it
updates the statistical information correctly.

Signed-off-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
---
memcontrol.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a8f1ff8..63f0922 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4698,12 +4698,110 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
return 0;
}

+#ifdef CONFIG_HUGETLB_PAGE
+static enum mc_target_type get_mctgt_type_hugetlb(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *pte, union mc_target *target)
+{
+ struct page *page = NULL;
+ pte_t entry;
+ enum mc_target_type ret = MC_TARGET_NONE;
+
+ if (!(mc.flags & MOVE_ANON))
+ return ret;
+
+ entry = huge_ptep_get(pte);
+ if (!pte_present(entry))
+ return ret;
+
+ page = pte_page(entry);
+ VM_BUG_ON_PAGE(!page || !PageHead(page), page);
+ if (likely(!PageSurplusCharge(page)))
+ return ret;
+ if (page->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target) {
+ get_page(page);
+ target->page = page;
+ }
+ }
+
+ return ret;
+}
+
+static int hugetlb_count_precharge_pte_range(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ struct mm_struct *mm = walk->mm;
+ spinlock_t *ptl;
+ union mc_target target;
+
+ ptl = huge_pte_lock(hstate_vma(vma), mm, pte);
+ if (get_mctgt_type_hugetlb(vma, addr, pte, &target) == MC_TARGET_PAGE) {
+ mc.precharge += (1 << compound_order(target.page));
+ put_page(target.page);
+ }
+ spin_unlock(ptl);
+
+ return 0;
+}
+
+static int hugetlb_move_charge_pte_range(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ struct mm_struct *mm = walk->mm;
+ spinlock_t *ptl;
+ enum mc_target_type target_type;
+ union mc_target target;
+ struct page *page;
+ unsigned long nr_pages;
+
+ ptl = huge_pte_lock(hstate_vma(vma), mm, pte);
+ target_type = get_mctgt_type_hugetlb(vma, addr, pte, &target);
+ if (target_type == MC_TARGET_PAGE) {
+ page = target.page;
+ nr_pages = (1 << compound_order(page));
+ if (mc.precharge < nr_pages) {
+ put_page(page);
+ goto unlock;
+ }
+ if (!mem_cgroup_move_account(page, true, mc.from, mc.to)) {
+ mc.precharge -= nr_pages;
+ mc.moved_charge += nr_pages;
+ }
+ put_page(page);
+ }
+unlock:
+ spin_unlock(ptl);
+
+ return 0;
+}
+#else
+static int hugetlb_count_precharge_pte_range(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ return 0;
+}
+
+static int hugetlb_move_charge_pte_range(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+ return 0;
+}
+#endif
+
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
{
unsigned long precharge;

struct mm_walk mem_cgroup_count_precharge_walk = {
.pmd_entry = mem_cgroup_count_precharge_pte_range,
+ .hugetlb_entry = hugetlb_count_precharge_pte_range,
.mm = mm,
};
down_read(&mm->mmap_sem);
@@ -4981,6 +5079,7 @@ static void mem_cgroup_move_charge(void)
{
struct mm_walk mem_cgroup_move_charge_walk = {
.pmd_entry = mem_cgroup_move_charge_pte_range,
+ .hugetlb_entry = hugetlb_move_charge_pte_range,
.mm = mc.mm,
};

--
Tsukada