memsw: handle swapaccount kernel parameter correctly

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8ab1d42..44f9f9c 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2236,7 +2236,12 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
 {
        int ret = -EINVAL;
        unsigned long flags;
-
+       /*
+        * The page is isolated from LRU. So, collapse function
+        * will not handle this page. But page splitting can happen.
+        * Do this check under compound_page_lock(). The caller should
+        * hold it.
+        */
        if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page))
                return -EBUSY;
 
@@ -2268,7 +2273,7 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc,
        struct cgroup *cg = child->css.cgroup;
        struct cgroup *pcg = cg->parent;
        struct mem_cgroup *parent;
-       int charge = PAGE_SIZE;
+       int page_size = PAGE_SIZE;
        unsigned long flags;
        int ret;
 
@@ -2281,22 +2286,24 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc,
                goto out;
        if (isolate_lru_page(page))
                goto put;
-       /* The page is isolated from LRU and we have no race with splitting */
-       charge = PAGE_SIZE << compound_order(page);
+
+       if (PageTransHuge(page))
+               page_size = HPAGE_SIZE;
 
        parent = mem_cgroup_from_cont(pcg);
-       ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge);
+       ret = __mem_cgroup_try_charge(NULL, gfp_mask,
+                               &parent, false, page_size);
        if (ret || !parent)
                goto put_back;
 
-       if (charge > PAGE_SIZE)
+       if (page_size > PAGE_SIZE)
                flags = compound_lock_irqsave(page);
 
-       ret = mem_cgroup_move_account(pc, child, parent, true, charge);
+       ret = mem_cgroup_move_account(pc, child, parent, true, page_size);
        if (ret)
-               mem_cgroup_cancel_charge(parent, charge);
+               mem_cgroup_cancel_charge(parent, page_size);
 
-       if (charge > PAGE_SIZE)
+       if (page_size > PAGE_SIZE)
                compound_unlock_irqrestore(page, flags);
 put_back:
        putback_lru_page(page);
@@ -5017,9 +5024,9 @@ struct cgroup_subsys mem_cgroup_subsys = {
 static int __init enable_swap_account(char *s)
 {
        /* consider enabled if no parameter or 1 is given */
-       if (!s || !strcmp(s, "1"))
+       if (!(*s) || !strcmp(s, "=1"))
                really_do_swap_account = 1;
-       else if (!strcmp(s, "0"))
+       else if (!strcmp(s, "=0"))
                really_do_swap_account = 0;
        return 1;
 }
@@ -5027,7 +5034,7 @@ __setup("swapaccount", enable_swap_account);
 
 static int __init disable_swap_account(char *s)
 {
-       enable_swap_account("0");
+       enable_swap_account("=0");
        return 1;
 }
 __setup("noswapaccount", disable_swap_account);