network locks up with udp traffic

[Adrian Chadd]

Hi!

To be clear:

* is your kernel modified in any way; and
* did witness give you a full stacktrace as part of the lock order
reversal? All of that would be good.

Thanks,




On 24 January 2015 at 09:53, Dmitry Sivachenko <trtrmitya at gmail.com> wrote:
>
>> On 24 янв. 2015 г., at 20:29, Adrian Chadd <adrian at freebsd.org> wrote:
>>
>> Hi,
>>
>> Can you compile your kernel with WITNESS and repeat this test? It
>> looks like it's stuck in some lock ordering thing between some UDP
>> paths and an inpcb lookup.
>>
>> It should log in dmesg the first time a LOR occurs, regardless of
>> whether it actively causes a hang.
>
>
>
> Here is what I got in dmesg just before my net locked up:
>
> lock order reversal:
>  1st 0xffffffff80e79008 pcbinfohash (pcbinfohash) @ /opt/WRK/src/sys/netinet6/udp6_usrreq.c:1202
>  2nd 0xffffffff80e78fb0 udp (udp) @ /opt/WRK/src/sys/netinet6/in6_pcb.c:614
> lock order reversal:
>  1st 0xffffffff80e79008 pcbinfohash (pcbinfohash) @ /opt/WRK/src/sys/netinet6/udp6_usrreq.c:1202
>  2nd 0xffffffff80e78d58 tcp (tcp) @ /opt/WRK/src/sys/netinet6/in6_pcb.c:614
> lock order reversal:
>  1st 0xffffffff80e79008 pcbinfohash (pcbinfohash) @ /opt/WRK/src/sys/netinet6/udp6_usrreq.c:1202
>  2nd 0xffffffff80e781c0 rip (rip) @ /opt/WRK/src/sys/netinet6/in6_pcb.c:614
>
> When I was saving this dmesg output to disk, I got another LOR:
>
> lock order reversal:
>  1st 0xfffffe0baf12fd78 bufwait (bufwait) @ /opt/WRK/src/sys/kern/vfs_bio.c:3065
>  2nd 0xfffff80011416c00 dirhash (dirhash) @ /opt/WRK/src/sys/ufs/ufs/ufs_dirhash.c:284
>
>
> Please tell me if I can provide more information to help tracking this down.
>
> Thanks!