memcg: fix gfp_mask of callers of charge

Fix misuse of gfp_kernel.

Now, most of callers of mem_cgroup_charge_xxx functions uses GFP_KERNEL.

I think that this is from the fact that page_cgroup *was* dynamically
allocated.

But now, we allocate all page_cgroup at boot.  And
mem_cgroup_try_to_free_pages() reclaim memory from GFP_HIGHUSER_MOVABLE +
specified GFP_RECLAIM_MASK.

  * This is because we just want to reduce memory usage.
    "Where we should reclaim from ?" is not a problem in memcg.

This patch modifies gfp masks to be GFP_HIGUSER_MOVABLE if possible.

Note: This patch is not for fixing behavior but for showing sane information
      in source code.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f568b1964551..c34eb52bdc3f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -808,8 +808,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
         }
         unlock_page_cgroup(pc);
         if (mem) {
-                ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
-                        ctype, mem);
+                ret = mem_cgroup_charge_common(newpage, NULL,
+                                        GFP_HIGHUSER_MOVABLE,
+                                        ctype, mem);
                 css_put(&mem->css);
         }
         return ret;
@@ -889,7 +890,8 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                         ret = -EBUSY;
                         break;
                 }
-                progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
+                progress = try_to_free_mem_cgroup_pages(memcg,
+                                GFP_HIGHUSER_MOVABLE);
                 if (!progress)
                         retry_count--;
         }