diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2fdd138..59ac95a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -26,6 +26,16 @@
 struct mm_struct;
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/*
+ * All "charge" functions with gfp_mask should use GFP_KERNEL or
+ * (gfp_mask & GFP_RECLAIM_MASK). In current implementatin, memcg doesn't
+ * alloc memory but reclaims memory from all available zones. So, "where I want
+ * memory from" bits of gfp_mask has no meaning. So any bits of that field is
+ * available but adding a rule is better. charge functions' gfp_mask should
+ * be set to GFP_KERNEL or gfp_mask & GFP_RECLAIM_MASK for avoiding ambiguous
+ * codes.
+ * (Of course, if memcg does memory allocation in future, GFP_KERNEL is sane.)
+ */
 
 extern int mem_cgroup_newpage_charge(struct page *page, struct mm_struct *mm,
 				gfp_t gfp_mask);
diff --git a/mm/filemap.c b/mm/filemap.c
index 2f55a1e..ceba0bd 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -460,7 +460,7 @@
 	VM_BUG_ON(!PageLocked(page));
 
 	error = mem_cgroup_cache_charge(page, current->mm,
-					gfp_mask & ~__GFP_HIGHMEM);
+					gfp_mask & GFP_RECLAIM_MASK);
 	if (error)
 		goto out;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9bf5d7c..b9cd57b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1248,7 +1248,7 @@
 	unlock_page_cgroup(pc);
 
 	if (mem) {
-		ret = mem_cgroup_try_charge(NULL, GFP_HIGHUSER_MOVABLE, &mem);
+		ret = mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem);
 		css_put(&mem->css);
 	}
 	*ptr = mem;
@@ -1378,7 +1378,7 @@
 			break;
 
 		progress = try_to_free_mem_cgroup_pages(memcg,
-				GFP_HIGHUSER_MOVABLE, false);
+				GFP_KERNEL, false);
   		if (!progress)			retry_count--;
 	}
 	return ret;
@@ -1418,7 +1418,7 @@
 			break;
 
 		oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
-		try_to_free_mem_cgroup_pages(memcg, GFP_HIGHUSER_MOVABLE, true);
+		try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true);
 		curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
 		if (curusage >= oldusage)
 			retry_count--;
@@ -1464,7 +1464,7 @@
 		}
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-		ret = mem_cgroup_move_parent(pc, mem, GFP_HIGHUSER_MOVABLE);
+		ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);
 		if (ret == -ENOMEM)
 			break;
 
@@ -1550,7 +1550,7 @@
 			goto out;
 		}
 		progress = try_to_free_mem_cgroup_pages(mem,
-						  GFP_HIGHUSER_MOVABLE, false);
+						  GFP_KERNEL, false);
 		if (!progress) {
 			nr_retries--;
 			/* maybe some writeback is necessary */
diff --git a/mm/memory.c b/mm/memory.c
index 1358012..e5bfbe6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2000,7 +2000,7 @@
 	cow_user_page(new_page, old_page, address, vma);
 	__SetPageUptodate(new_page);
 
-	if (mem_cgroup_newpage_charge(new_page, mm, GFP_HIGHUSER_MOVABLE))
+	if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
 		goto oom_free_new;
 
 	/*
@@ -2431,8 +2431,7 @@
 	lock_page(page);
 	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 
-	if (mem_cgroup_try_charge_swapin(mm, page,
-				GFP_HIGHUSER_MOVABLE, &ptr) == -ENOMEM) {
+	if (mem_cgroup_try_charge_swapin(mm, page, GFP_KERNEL, &ptr)) {
 		ret = VM_FAULT_OOM;
 		unlock_page(page);
 		goto out;
@@ -2524,7 +2523,7 @@
 		goto oom;
 	__SetPageUptodate(page);
 
-	if (mem_cgroup_newpage_charge(page, mm, GFP_HIGHUSER_MOVABLE))
+	if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))
 		goto oom_free_page;
 
 	entry = mk_pte(page, vma->vm_page_prot);
@@ -2615,8 +2614,7 @@
 				ret = VM_FAULT_OOM;
 				goto out;
 			}
-			if (mem_cgroup_newpage_charge(page,
-						mm, GFP_HIGHUSER_MOVABLE)) {
+			if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL)) {
 				ret = VM_FAULT_OOM;
 				page_cache_release(page);
 				goto out;
diff --git a/mm/shmem.c b/mm/shmem.c
index adf5c3e..bbb7b04 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -932,8 +932,8 @@
 	 * Charge page using GFP_HIGHUSER_MOVABLE while we can wait.
 	 * charged back to the user(not to caller) when swap account is used.
 	 */
-	error = mem_cgroup_cache_charge_swapin(page,
-			current->mm, GFP_HIGHUSER_MOVABLE, true);
+	error = mem_cgroup_cache_charge_swapin(page, current->mm, GFP_KERNEL,
+					true);
 	if (error)
 		goto out;
 	error = radix_tree_preload(GFP_KERNEL);
@@ -1275,7 +1275,7 @@
 			 * charge against this swap cache here.
 			 */
 			if (mem_cgroup_cache_charge_swapin(swappage,
-						current->mm, gfp, false)) {
+				current->mm, gfp & GFP_RECLAIM_MASK, false)) {
 				page_cache_release(swappage);
 				error = -ENOMEM;
 				goto failed;
@@ -1393,7 +1393,7 @@
 
 			/* Precharge page while we can wait, compensate after */
 			error = mem_cgroup_cache_charge(filepage, current->mm,
-					GFP_HIGHUSER_MOVABLE);
+					GFP_KERNEL);
 			if (error) {
 				page_cache_release(filepage);
 				shmem_unacct_blocks(info->flags, 1);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 0579d90..da422c4 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -698,8 +698,7 @@
 	pte_t *pte;
 	int ret = 1;
 
-	if (mem_cgroup_try_charge_swapin(vma->vm_mm, page,
-					GFP_HIGHUSER_MOVABLE, &ptr))
+	if (mem_cgroup_try_charge_swapin(vma->vm_mm, page, GFP_KERNEL, &ptr))
 		ret = -ENOMEM;
 
 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);