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, 3 insertions, 3 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 5941f9801363..bd9b4ea307b2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -928,8 +928,8 @@ found:
         error = 1;
         if (!inode)
                 goto out;
-        /* Precharge page using GFP_KERNEL while we can wait */
-        error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
+        /* Charge page using GFP_HIGHUSER_MOVABLE while we can wait */
+        error = mem_cgroup_cache_charge(page, current->mm, GFP_HIGHUSER_MOVABLE);
         if (error)
                 goto out;
         error = radix_tree_preload(GFP_KERNEL);
@@ -1379,7 +1379,7 @@ repeat:
 
                         /* Precharge page while we can wait, compensate after */
                         error = mem_cgroup_cache_charge(filepage, current->mm,
-                                                        gfp & ~__GFP_HIGHMEM);
+                                        GFP_HIGHUSER_MOVABLE);
                         if (error) {
                                 page_cache_release(filepage);
                                 shmem_unacct_blocks(info->flags, 1);