mm: memcg: lockdep annotation for memcg OOM lock
The memcg OOM lock is a mutex-type lock that is open-coded due to
memcg's special needs. Add annotations for lockdep coverage.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
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 623d5c8..7e11cb7 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);