> On Nov 16, 2017, at 9:01 PM, Stephen Hemminger <step...@networkplumber.org> > wrote: > > On Thu, 16 Nov 2017 18:05:35 +0400 > Ilya Matveychikov <matvejchi...@gmail.com> wrote: > >> Fixes: 139debc42dc0 ("mbuf: move chaining from ip_frag library") >> Cc: simon.kagst...@netinsight.net >> >> Signed-off-by: Ilya V. Matveychikov <matvejchi...@gmail.com> >> --- >> lib/librte_mbuf/rte_mbuf.h | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h >> index ce8a05ddf..2126dc94b 100644 >> --- a/lib/librte_mbuf/rte_mbuf.h >> +++ b/lib/librte_mbuf/rte_mbuf.h >> @@ -1828,9 +1828,12 @@ static inline int rte_pktmbuf_chain(struct rte_mbuf >> *head, struct rte_mbuf *tail >> head->nb_segs += tail->nb_segs; >> head->pkt_len += tail->pkt_len; >> >> - /* pkt_len is only set in the head */ >> + /* nb_segs and pkt_len are only set in the head */ >> + tail->nb_segs = 1; >> tail->pkt_len = tail->data_len; >> >> + __rte_mbuf_sanity_check(head, 1); >> + >> return 0; >> } > > My understanding is that nb_segs and pkt_len are only valid > in head. For other packets in the chain nb_segs and pkt_len > can be anything.
So why not to keep them in consistency with multi-seg logic? I mean that pkt_len/nb_segs for the head always have meaning but for the rest of chain pkt_len is the same as data_len and nb_segs := 1