Merge branch 'akpm' (fixes from Andrew Morton)
Merge four more fixes from Andrew Morton.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
lib/scatterlist.c: don't flush_kernel_dcache_page on slab page
mm: memcg: fix test for child groups
mm: memcg: lockdep annotation for memcg OOM lock
mm: memcg: use proper memcg in limit bypass
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index a685c8a..d16fa29 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -577,7 +577,8 @@
miter->__offset += miter->consumed;
miter->__remaining -= miter->consumed;
- if (miter->__flags & SG_MITER_TO_SG)
+ if ((miter->__flags & SG_MITER_TO_SG) &&
+ !PageSlab(miter->page))
flush_kernel_dcache_page(miter->page);
if (miter->__flags & SG_MITER_ATOMIC) {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 497ec33..e632782 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -54,6 +54,7 @@
#include <linux/page_cgroup.h>
#include <linux/cpu.h>
#include <linux/oom.h>
+#include <linux/lockdep.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
@@ -2046,6 +2047,12 @@
return total;
}
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map memcg_oom_lock_dep_map = {
+ .name = "memcg_oom_lock",
+};
+#endif
+
static DEFINE_SPINLOCK(memcg_oom_lock);
/*
@@ -2083,7 +2090,8 @@
}
iter->oom_lock = false;
}
- }
+ } else
+ mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
spin_unlock(&memcg_oom_lock);
@@ -2095,6 +2103,7 @@
struct mem_cgroup *iter;
spin_lock(&memcg_oom_lock);
+ mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
for_each_mem_cgroup_tree(iter, memcg)
iter->oom_lock = false;
spin_unlock(&memcg_oom_lock);
@@ -2765,10 +2774,10 @@
*ptr = memcg;
return 0;
nomem:
- *ptr = NULL;
- if (gfp_mask & __GFP_NOFAIL)
- return 0;
- return -ENOMEM;
+ if (!(gfp_mask & __GFP_NOFAIL)) {
+ *ptr = NULL;
+ return -ENOMEM;
+ }
bypass:
*ptr = root_mem_cgroup;
return -EINTR;
@@ -4950,31 +4959,18 @@
} while (usage > 0);
}
-/*
- * This mainly exists for tests during the setting of set of use_hierarchy.
- * Since this is the very setting we are changing, the current hierarchy value
- * is meaningless
- */
-static inline bool __memcg_has_children(struct mem_cgroup *memcg)
-{
- struct cgroup_subsys_state *pos;
-
- /* bounce at first found */
- css_for_each_child(pos, &memcg->css)
- return true;
- return false;
-}
-
-/*
- * Must be called with memcg_create_mutex held, unless the cgroup is guaranteed
- * to be already dead (as in mem_cgroup_force_empty, for instance). This is
- * from mem_cgroup_count_children(), in the sense that we don't really care how
- * many children we have; we only need to know if we have any. It also counts
- * any memcg without hierarchy as infertile.
- */
static inline bool memcg_has_children(struct mem_cgroup *memcg)
{
- return memcg->use_hierarchy && __memcg_has_children(memcg);
+ lockdep_assert_held(&memcg_create_mutex);
+ /*
+ * The lock does not prevent addition or deletion to the list
+ * of children, but it prevents a new child from being
+ * initialized based on this parent in css_online(), so it's
+ * enough to decide whether hierarchically inherited
+ * attributes can still be changed or not.
+ */
+ return memcg->use_hierarchy &&
+ !list_empty(&memcg->css.cgroup->children);
}
/*
@@ -5054,7 +5050,7 @@
*/
if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
(val == 1 || val == 0)) {
- if (!__memcg_has_children(memcg))
+ if (list_empty(&memcg->css.cgroup->children))
memcg->use_hierarchy = val;
else
retval = -EBUSY;