memcg: convert per-cpu stock from bytes to page granularity
We never keep subpage quantities in the per-cpu stock.
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 09a4506..91120a0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1650,14 +1650,14 @@
#define CHARGE_SIZE (32 * PAGE_SIZE)
struct memcg_stock_pcp {
struct mem_cgroup *cached; /* this never be root cgroup */
- int charge;
+ unsigned int nr_pages;
struct work_struct work;
};
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
static atomic_t memcg_drain_count;
/*
- * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed
+ * Try to consume stocked charge on this cpu. If success, one page is consumed
* from local stock and true is returned. If the stock is 0 or charges from a
* cgroup which is not current target, returns false. This stock will be
* refilled.
@@ -1668,8 +1668,8 @@
bool ret = true;
stock = &get_cpu_var(memcg_stock);
- if (mem == stock->cached && stock->charge)
- stock->charge -= PAGE_SIZE;
+ if (mem == stock->cached && stock->nr_pages)
+ stock->nr_pages--;
else /* need to call res_counter_charge */
ret = false;
put_cpu_var(memcg_stock);
@@ -1683,13 +1683,15 @@
{
struct mem_cgroup *old = stock->cached;
- if (stock->charge) {
- res_counter_uncharge(&old->res, stock->charge);
+ if (stock->nr_pages) {
+ unsigned long bytes = stock->nr_pages * PAGE_SIZE;
+
+ res_counter_uncharge(&old->res, bytes);
if (do_swap_account)
- res_counter_uncharge(&old->memsw, stock->charge);
+ res_counter_uncharge(&old->memsw, bytes);
+ stock->nr_pages = 0;
}
stock->cached = NULL;
- stock->charge = 0;
}
/*
@@ -1706,7 +1708,7 @@
* Cache charges(val) which is from res_counter, to local per_cpu area.
* This will be consumed by consume_stock() function, later.
*/
-static void refill_stock(struct mem_cgroup *mem, int val)
+static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages)
{
struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
@@ -1714,7 +1716,7 @@
drain_stock(stock);
stock->cached = mem;
}
- stock->charge += val;
+ stock->nr_pages += nr_pages;
put_cpu_var(memcg_stock);
}
@@ -2012,7 +2014,7 @@
} while (ret != CHARGE_OK);
if (csize > page_size)
- refill_stock(mem, csize - page_size);
+ refill_stock(mem, (csize - page_size) >> PAGE_SHIFT);
css_put(&mem->css);
done:
*memcg = mem;