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.letti...@iet.unipi.it _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
