On 21.04.2016 15:31, Eric Dumazet wrote:
> On Thu, 2016-04-21 at 05:05 -0400, valdis.kletni...@vt.edu wrote:
>> On Thu, 21 Apr 2016 09:42:12 +0200, Hannes Frederic Sowa said:
>>> Hi,
>>>
>>> On Thu, Apr 21, 2016, at 02:30, Valdis Kletnieks wrote:
>>>> linux-next 20160420 is whining at an incredible rate - in 20 minutes of
>>>> uptime, I piled up some 41,000 hits from all over the place (cleaned up
>>>> to skip the CPU and PID so the list isn't quite so long):
>>>
>>> Thanks for the report. Can you give me some more details:
>>>
>>> Is this an nfs socket? Do you by accident know if this socket went
>>> through xs_reclassify_socket at any point? We do hold the appropriate
>>> locks at that point but I fear that the lockdep reinitialization
>>> confused lockdep.
>>
>> It wasn't an NFS socket, as NFS wasn't even active at the time. I'm
>> reasonably
>> sure that multiple sockets were in play, given that tcp_v6_rcv and
>> udpv6_queue_rcv_skb were both implicated. I strongly suspect that pretty
>> much
>> any IPv6 traffic could do it - the frequency dropped off quite a bit when I
>> closed firefox, which is usually a heavy network hitter on my laptop.
>
>
> Looks like the following patch is needed, can you try it please ?
>
> Thanks !
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index d997ec13a643..db8301c76d50 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -1350,7 +1350,8 @@ static inline bool lockdep_sock_is_held(const struct
> sock *csk)
> {
> struct sock *sk = (struct sock *)csk;
>
> - return lockdep_is_held(&sk->sk_lock) ||
> + return !debug_locks ||
> + lockdep_is_held(&sk->sk_lock) ||
> lockdep_is_held(&sk->sk_lock.slock);
> }
> #endif
I would prefer to add debug_locks at the WARN_ON level, like
WARN_ON(debug_locks && !lockdep_sock_is_held(sk)), but I am not sure if
this fixes the initial splat.
Thanks Eric!
