82576 + NETMAP + VLAN

[Adrian Chadd]

hi,

please bug me in a couple weeks. still moving house, etc.


-a


On 16 February 2016 at 02:30, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
> On Tue, Feb 16, 2016 at 11:23:20AM +0100, Giuseppe Lettieri wrote:
>
>> I am sorry, I did not participate to the implementation of kqueue
>> support and I am not able to comment. Luigi and Adrian should know, however.
>
> Thanks!
>
>> Cheers,
>> Giuseppe
>>
>> Il 15/02/2016 22:44, Slawa Olhovchenkov ha scritto:
>> > On Mon, Feb 15, 2016 at 05:02:36PM +0100, Giuseppe Lettieri wrote:
>> >
>> >> Il 15/02/2016 16:13, Slawa Olhovchenkov ha scritto:
>> >>> On Mon, Feb 15, 2016 at 04:10:30PM +0100, Giuseppe Lettieri wrote:
>> >>>
>> >>>> Hi Slawa,
>> >>>>
>> >>>> I think WITNESS is seeing a false positive, since those two are always
>> >>>> different mutexes.
>> >>>>
>> >>>> The actual deadlock you experience should be caused by something else. I
>> >>>
>> >>> Are you sure? When deadlock occur I am see threads waiting on nm_kn_lock.
>> >>
>> >> The deadlock I mentioned still involves nm_kn_locks, sorry if I was not
>> >> clear about that. I am just saying that we never try to take the same
>> >> lock that we already holding.
>> >>
>> >> Nonetheless, there are indeed problems in the path that WITNESS has
>> >> seen. The problem is that pipes have to notify the other end while
>> >> called by kevent. kevent holds the nm_kn_lock on the TX src ring and the
>> >> notification takes the nm_kn_lock on the RX dst ring.
>> >
>> > Can you comment other issuses? Is this by design or is this bug?
>> >
>> > - with kevent sync for transmiting need first register
>> >    EVFILT_WRITE/EV_DISABLE and after every write
>> >    EVFILT_WRITE/EV_DISPATCH
>> >
>> > - with kevent sync all opening /dev/netmap and registering need do
>> >    from same thread as kevent using for sinc (unless no RX/TX).
>> >
>> >
>>
>>
>> --
>> Dr. Ing. Giuseppe Lettieri
>> Dipartimento di Ingegneria della Informazione
>> Universita' di Pisa
>> Largo Lucio Lazzarino 1, 56122 Pisa - Italy
>> Ph. : (+39) 050-2217.649 (direct) .599 (switch)
>> Fax : (+39) 050-2217.600
>> e-mail: g.lettieri at iet.unipi.it