memcg: keep only one charge cancelling function

We have two charge cancelling functions: one takes a page count, the other
a page size.  The second one just divides the parameter by PAGE_SIZE and
then calls the first one.  This is trivial, no need for an extra function.

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

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8f9381976c59b203bd7ef2a5550a50d1fd2b9096..09a450684f7029e4696748341ac1ac3b2c05a3ae 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2031,21 +2031,17 @@ bypass:
  * gotten by try_charge().
  */
 static void __mem_cgroup_cancel_charge(struct mem_cgroup *mem,
-                                                       unsigned long count)
+                                      unsigned int nr_pages)
 {
        if (!mem_cgroup_is_root(mem)) {
-               res_counter_uncharge(&mem->res, PAGE_SIZE * count);
+               unsigned long bytes = nr_pages * PAGE_SIZE;
+
+               res_counter_uncharge(&mem->res, bytes);
                if (do_swap_account)
-                       res_counter_uncharge(&mem->memsw, PAGE_SIZE * count);
+                       res_counter_uncharge(&mem->memsw, bytes);
        }
 }
 
-static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
-                                    int page_size)
-{
-       __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
-}
-
 /*
  * A helper function to get mem_cgroup from ID. must be called under
  * rcu_read_lock(). The caller must check css_is_removed() or some if
@@ -2104,7 +2100,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
        lock_page_cgroup(pc);
        if (unlikely(PageCgroupUsed(pc))) {
                unlock_page_cgroup(pc);
-               mem_cgroup_cancel_charge(mem, page_size);
+               __mem_cgroup_cancel_charge(mem, nr_pages);
                return;
        }
        /*
@@ -2242,7 +2238,7 @@ static int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc,
        mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages);
        if (uncharge)
                /* This is not "cancel", but cancel_charge does all we need. */
-               mem_cgroup_cancel_charge(from, charge_size);
+               __mem_cgroup_cancel_charge(from, nr_pages);
 
        /* caller should have done css_get */
        pc->mem_cgroup = to;
@@ -2307,7 +2303,7 @@ static int mem_cgroup_move_parent(struct page *page,
 
        ret = mem_cgroup_move_account(page, pc, child, parent, true, page_size);
        if (ret)
-               mem_cgroup_cancel_charge(parent, page_size);
+               __mem_cgroup_cancel_charge(parent, page_size >> PAGE_SHIFT);
 
        if (page_size > PAGE_SIZE)
                compound_unlock_irqrestore(page, flags);
@@ -2538,7 +2534,7 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
                return;
        if (!mem)
                return;
-       mem_cgroup_cancel_charge(mem, PAGE_SIZE);
+       __mem_cgroup_cancel_charge(mem, 1);
 }
 
 static void