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). _______________________________________________ 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"
