Merge branch 'tip/rtmutex' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into core/locking

*git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace tip/rtmutex:
   rtmutex: Simplify PI algorithm and make highest prio task get lock

1 files changed, 21 insertions, 10 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index db76ef726293..3878cfe399dc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1832,6 +1832,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
 		if (likely(!ret))
 			return CHARGE_OK;
 
+		res_counter_uncharge(&mem->res, csize);
 		mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
 		flags |= MEM_CGROUP_RECLAIM_NOSWAP;
 	} else
@@ -2144,6 +2145,8 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
 	struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
 	unsigned long flags;
 
+	if (mem_cgroup_disabled())
+		return;
 	/*
 	 * We have no races with charge/uncharge but will have races with
 	 * page state accounting.
@@ -2233,7 +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;
 
@@ -2265,7 +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;
 
@@ -2278,23 +2286,26 @@ 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);
-put_back:
-	if (charge > PAGE_SIZE)
+		mem_cgroup_cancel_charge(parent, page_size);
+
+	if (page_size > PAGE_SIZE)
 		compound_unlock_irqrestore(page, flags);
+put_back:
 	putback_lru_page(page);
 put:
 	put_page(page);