6 files changed, 25 insertions, 18 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2fdd1380bf0a..59ac95a64508 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -26,6 +26,16 @@ struct page;
 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 2f55a1e2baf7..ceba0bd03662 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -460,7 +460,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
         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 9bf5d7c8ede7..b9cd57b667d6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1248,7 +1248,7 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
         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 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                         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 @@ int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
                         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 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem,
                 }
                 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 @@ try_to_free:
                         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 1358012ffa73..e5bfbe6b594c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2000,7 +2000,7 @@ gotten:
         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 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
         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 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 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 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                 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 adf5c3eedbc9..bbb7b043c986 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -932,8 +932,8 @@ found:
          * 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 @@ repeat:
                          * 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 @@ repeat:
 
                         /* 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 0579d9069b61..da422c47e2ee 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -698,8 +698,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
         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);