On Tue, 4 Nov 2025 at 11:02, David Marchand <[email protected]> wrote: > > When debugging TSO and other checksum offloads, dumping the various > l*_len fields and TSO segmentation size can be helpful. > > Example in OVS that dumps a mbuf on rte_eth_tx_prepare failure: > > Before: > netdev_dpdk(pmd-c30/id:11)|DBG|dpdk0: First invalid packet: > dump mbuf at 0x2201a916c0, iova=0x2200800580, buf_len=6864 > pkt_len=6804, ol_flags=0x3114800000000102, nb_segs=1, port=65535, ptype=0 > segment at 0x2201a916c0, data=0x22008005b2, len=6804, off=50, refcnt=1 > Dump data at [0x22008005b2], len=6804 > ... > > After: > netdev_dpdk(pmd-c30/id:11)|DBG|dpdk0: First invalid packet: > dump mbuf at 0x2201a916c0, iova=0x2200800580, buf_len=6864, pkt_len=6804 > outer_l2_len=14, outer_l3_len=40, l2_len=38, l3_len=40, l4_len=32 > ol_flags=0x3114800000000102, nb_segs=1, port=65535, ptype=0 > segment at 0x2201a916c0, data=0x22008005b2, len=6804, off=50, refcnt=1 > Dump data at [0x22008005b2], len=6804 > ... > > Signed-off-by: David Marchand <[email protected]> > --- > lib/mbuf/rte_mbuf.c | 41 +++++++++++++++++++++++++++++++++++++---- > 1 file changed, 37 insertions(+), 4 deletions(-) > > diff --git a/lib/mbuf/rte_mbuf.c b/lib/mbuf/rte_mbuf.c > index 0d931c7a15..12710a59df 100644 > --- a/lib/mbuf/rte_mbuf.c > +++ b/lib/mbuf/rte_mbuf.c > @@ -750,10 +750,43 @@ rte_pktmbuf_dump(FILE *f, const struct rte_mbuf *m, > unsigned dump_len) > > __rte_mbuf_sanity_check(m, 1); > > - fprintf(f, "dump mbuf at %p, iova=%#" PRIx64 ", buf_len=%u\n", m, > rte_mbuf_iova_get(m), > - m->buf_len); > - fprintf(f, " pkt_len=%u, ol_flags=%#"PRIx64", nb_segs=%u, port=%u", > - m->pkt_len, m->ol_flags, m->nb_segs, m->port); > + fprintf(f, "dump mbuf at %p, iova=%#" PRIx64 ", buf_len=%u, > pkt_len=%u\n", > + m, rte_mbuf_iova_get(m), m->buf_len, m->pkt_len); > + if (m->ol_flags & RTE_MBUF_F_TX_OFFLOAD_MASK) { > + const char *sep = ""; > + > + fprintf(f, " "); > + if (m->outer_l2_len != 0) { > + fprintf(f, "%souter_l2_len=%u", sep, m->outer_l2_len);
One more round will be needed for MSVC (CI did not report it on v1, some tests did not run..). ../lib/mbuf/rte_mbuf.c(760): error C2220: the following warning is treated as an error ../lib/mbuf/rte_mbuf.c(760): warning C4477: 'fprintf' : format string '%u' requires an argument of type 'unsigned int', but variadic argument 2 has type 'const uint64_t' ../lib/mbuf/rte_mbuf.c(760): note: consider using '%llu' in the format string ../lib/mbuf/rte_mbuf.c(760): note: consider using '%Iu' in the format string ../lib/mbuf/rte_mbuf.c(760): note: consider using '%I64u' in the format string This is probably because of the bitfields we have for the tx_offload field. lib/mbuf/rte_mbuf_core.h: RTE_MBUF_L2_LEN_BITS = 7, lib/mbuf/rte_mbuf_core.h: RTE_MBUF_L3_LEN_BITS = 9, lib/mbuf/rte_mbuf_core.h: RTE_MBUF_L4_LEN_BITS = 8, lib/mbuf/rte_mbuf_core.h: RTE_MBUF_OUTL3_LEN_BITS = 9, lib/mbuf/rte_mbuf_core.h: RTE_MBUF_OUTL2_LEN_BITS = 7, lib/mbuf/rte_mbuf_core.h: uint64_t l2_len:RTE_MBUF_L2_LEN_BITS; lib/mbuf/rte_mbuf_core.h: uint64_t l3_len:RTE_MBUF_L3_LEN_BITS; lib/mbuf/rte_mbuf_core.h: uint64_t l4_len:RTE_MBUF_L4_LEN_BITS; lib/mbuf/rte_mbuf_core.h: uint64_t outer_l3_len:RTE_MBUF_OUTL3_LEN_BITS; lib/mbuf/rte_mbuf_core.h: uint64_t outer_l2_len:RTE_MBUF_OUTL2_LEN_BITS; Passing %PRIu64 instead of %u breaks build with gcc and clang. ../lib/mbuf/rte_mbuf.c: In function ‘rte_pktmbuf_dump’: ../lib/mbuf/rte_mbuf.c:760:36: error: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘int’ [-Werror=format=] 760 | fprintf(f, "%souter_l2_len=%"PRIu64, sep, m->outer_l2_len); | ^~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~ | | | int I'll go with simple casting, like: + fprintf(f, "%souter_l2_len=%u", sep, (unsigned int)m->outer_l2_len); -- David Marchand
