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-rw-r--r--mm/memcontrol.c85
1 files changed, 77 insertions, 8 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c8d00a9780bc..b2ee6df0e9bb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5256,6 +5256,41 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
return ret;
}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * We don't consider swapping or file mapped pages because THP does not
+ * support them for now.
+ * Caller should make sure that pmd_trans_huge(pmd) is true.
+ */
+static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ struct page *page = NULL;
+ struct page_cgroup *pc;
+ enum mc_target_type ret = MC_TARGET_NONE;
+
+ page = pmd_page(pmd);
+ VM_BUG_ON(!page || !PageHead(page));
+ if (!move_anon())
+ return ret;
+ pc = lookup_page_cgroup(page);
+ if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
+ ret = MC_TARGET_PAGE;
+ if (target) {
+ get_page(page);
+ target->page = page;
+ }
+ }
+ return ret;
+}
+#else
+static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t pmd, union mc_target *target)
+{
+ return MC_TARGET_NONE;
+}
+#endif
+
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
unsigned long addr, unsigned long end,
struct mm_walk *walk)
@@ -5264,9 +5299,12 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
pte_t *pte;
spinlock_t *ptl;
- split_huge_page_pmd(walk->mm, pmd);
- if (pmd_trans_unstable(pmd))
+ if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
+ mc.precharge += HPAGE_PMD_NR;
+ spin_unlock(&vma->vm_mm->page_table_lock);
return 0;
+ }
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
for (; addr != end; pte++, addr += PAGE_SIZE)
@@ -5425,18 +5463,49 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
struct vm_area_struct *vma = walk->private;
pte_t *pte;
spinlock_t *ptl;
+ enum mc_target_type target_type;
+ union mc_target target;
+ struct page *page;
+ struct page_cgroup *pc;
- split_huge_page_pmd(walk->mm, pmd);
- if (pmd_trans_unstable(pmd))
+ /*
+ * We don't take compound_lock() here but no race with splitting thp
+ * happens because:
+ * - if pmd_trans_huge_lock() returns 1, the relevant thp is not
+ * under splitting, which means there's no concurrent thp split,
+ * - if another thread runs into split_huge_page() just after we
+ * entered this if-block, the thread must wait for page table lock
+ * to be unlocked in __split_huge_page_splitting(), where the main
+ * part of thp split is not executed yet.
+ */
+ if (pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (!mc.precharge) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+ }
+ target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
+ if (target_type == MC_TARGET_PAGE) {
+ page = target.page;
+ if (!isolate_lru_page(page)) {
+ pc = lookup_page_cgroup(page);
+ if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
+ pc, mc.from, mc.to,
+ false)) {
+ mc.precharge -= HPAGE_PMD_NR;
+ mc.moved_charge += HPAGE_PMD_NR;
+ }
+ putback_lru_page(page);
+ }
+ put_page(page);
+ }
+ spin_unlock(&vma->vm_mm->page_table_lock);
return 0;
+ }
+
retry:
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
for (; addr != end; addr += PAGE_SIZE) {
pte_t ptent = *(pte++);
- union mc_target target;
- int type;
- struct page *page;
- struct page_cgroup *pc;
swp_entry_t ent;
if (!mc.precharge)