phy: allwinner: Make PHY_SUN6I_MIPI_DPHY depend on COMMON_CLK

[linux-2.6-microblaze.git] / ipc / namespace.c

diff --git a/ipc/namespace.c b/ipc/namespace.c
index fdc3b5f..24e7b45 100644 (file)
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -117,6 +117,10 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
 
 static void free_ipc_ns(struct ipc_namespace *ns)
 {
+       /* mq_put_mnt() waits for a grace period as kern_unmount()
+        * uses synchronize_rcu().
+        */
+       mq_put_mnt(ns);
        sem_exit_ns(ns);
        msg_exit_ns(ns);
        shm_exit_ns(ns);
@@ -127,6 +131,21 @@ static void free_ipc_ns(struct ipc_namespace *ns)
        kfree(ns);
 }
 
+static LLIST_HEAD(free_ipc_list);
+static void free_ipc(struct work_struct *unused)
+{
+       struct llist_node *node = llist_del_all(&free_ipc_list);
+       struct ipc_namespace *n, *t;
+
+       llist_for_each_entry_safe(n, t, node, mnt_llist)
+               free_ipc_ns(n);
+}
+
+/*
+ * The work queue is used to avoid the cost of synchronize_rcu in kern_unmount.
+ */
+static DECLARE_WORK(free_ipc_work, free_ipc);
+
 /*
  * put_ipc_ns - drop a reference to an ipc namespace.
  * @ns: the namespace to put
@@ -148,8 +167,9 @@ void put_ipc_ns(struct ipc_namespace *ns)
        if (refcount_dec_and_lock(&ns->count, &mq_lock)) {
                mq_clear_sbinfo(ns);
                spin_unlock(&mq_lock);
-               mq_put_mnt(ns);
-               free_ipc_ns(ns);
+
+               if (llist_add(&ns->mnt_llist, &free_ipc_list))
+                       schedule_work(&free_ipc_work);
        }
 }