dummy: fix rcu_sched self-detected stalls

Trying to "modprobe dummy numdummies=30000" triggers :

INFO: rcu_sched self-detected stall on CPU { 8} (t=60000 jiffies)

After this splat, RTNL is locked and reboot is needed.

We must call cond_resched() to avoid this, even holding RTNL.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index 442d91a2747b..bab0158f1cc3 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -187,8 +187,10 @@ static int __init dummy_init_module(void)
         rtnl_lock();
         err = __rtnl_link_register(&dummy_link_ops);
 
-        for (i = 0; i < numdummies && !err; i++)
+        for (i = 0; i < numdummies && !err; i++) {
                 err = dummy_init_one();
+                cond_resched();
+        }
         if (err < 0)
                 __rtnl_link_unregister(&dummy_link_ops);
         rtnl_unlock();