[dpdk-dev] [PATCH] pktgen-dpdk: fix low performance in VM virtio pmd mode

Bin Huang huangbin.mails at gmail.com
Wed Dec 20 09:04:15 CET 2017

pktgen pre-allocated TX data in mbuf would be modified by virtio pmd driver due to virtio pkt head extension.
it will caused mbuf data_len keep growing, packets size on wire growing, then tx pps performance drop.

set corresponding mbuf data_len in pktmbuf reset to fix it.

Signed-off-by: Bin Huang <huangbin.mails at gmail.com>
Signed-off-by: Bin Huang <bin.huang at hxt-semitech.com>
Signed-off-by: Bin Huang <huangbin.mails at gmail.com>
 lib/common/mbuf.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/common/mbuf.h b/lib/common/mbuf.h
index 759f95d..93065f6 100644
--- a/lib/common/mbuf.h
+++ b/lib/common/mbuf.h
@@ -18,6 +18,7 @@ pktmbuf_reset(struct rte_mbuf *m)
 	m->nb_segs = 1;
 	m->port = 0xff;
+	m->data_len = m->pkt_len;
 	m->data_off = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
 		RTE_PKTMBUF_HEADROOM : m->buf_len;

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