On Fri, Nov 13, 2015 at 03:40:04PM -0800, Luigi Rizzo wrote: > On Fri, Nov 13, 2015 at 1:30 PM, Slawa Olhovchenkov <[email protected]> wrote: > > I am see strange things: like NETMAP stop transmit after `head` and `cur` > > touch `tail`. > > > > But: > > > > /* > > * check if space is available in the ring. > > */ > > static inline int > > nm_ring_empty(struct netmap_ring *ring) > > { > > return (ring->cur == ring->tail); > > } > > > > i.e. if cur == (tail-1) mod ring_size -- space is available in the > > ring and I can put packet in output buffer. > > The design requires to leave at least one empty slot in the buffer. > The name of the function is correct, the comment is probably not, > unless a bug has creeped in recently the code was very careful > in not using the free slot that separates the two regions.
Please, do some clarification, in case for transmit patch: - can I put in txring in case cur == (tail-1) mod ring_size? - can I use poll with only `events |= POLLIN` for transmiting? in case for receive patch: - can I detect input overflow? > cheers > luigi > > > After put this packet ring is full, but no transmiting. > > > > This is bug? > > _______________________________________________ > > [email protected] mailing list > > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > > To unsubscribe, send any mail to "[email protected]" > > > > -- > -----------------------------------------+------------------------------- > Prof. Luigi RIZZO, [email protected] . Dip. di Ing. dell'Informazione > http://www.iet.unipi.it/~luigi/ . Universita` di Pisa > TEL +39-050-2217533 . via Diotisalvi 2 > Mobile +39-338-6809875 . 56122 PISA (Italy) > -----------------------------------------+------------------------------- _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
