[dpdk-users] Increasing the NB_MBUFs of PktMbuf MemPool

Wajeeha Javed wajeeha.javed123 at gmail.com
Fri Oct 12 06:48:06 CEST 2018


I am in the process of developing  DPDK based Application where I would
like to delay the packets for about 2 secs. There are two ports connected
to DPDK App and sending traffic of 64 bytes size packets at a line rate of
10GB/s. Within 2 secs, I will have 28 Million packets for each of the port
in delay application. The maximum RX Descriptor size is 16384. I am unable
to increase the number of Rx descriptors more than 16384 value. Is it
possible to increase the number of Rx descriptors to a large value. e.g.
65536.  Therefore I copied the mbufs using the pktmbuf copy code(shown
below) and free the packet received. Now the issue is that I can not copy
more than 5 million packets because the  nb_mbufs of the mempool can't be
more than 5 Million (#define NB_MBUF 5000000). If I increase the NB_MBUF
macro from more than 5 Million, the error is returned unable to init mbuf
pool. Is there a possible way to increase the mempool size?

Furthermore, kindly guide me if this is the appropriate mailing list for
asking this type of questions.


static inline struct rte_mbuf *

pktmbuf_copy(struct rte_mbuf *md, struct rte_mempool *mp)
struct rte_mbuf *mc = NULL;
struct rte_mbuf **prev = &mc;

do {
    struct rte_mbuf *mi;

    mi = rte_pktmbuf_alloc(mp);
    if (unlikely(mi == NULL)) {

        rte_exit(EXIT_FAILURE, "Unable to Allocate Memory. Memory
        return NULL;

    mi->data_off = md->data_off;
    mi->data_len = md->data_len;
    mi->port = md->port;
    mi->vlan_tci = md->vlan_tci;
    mi->tx_offload = md->tx_offload;
    mi->hash = md->hash;

    mi->next = NULL;
    mi->pkt_len = md->pkt_len;
    mi->nb_segs = md->nb_segs;
    mi->ol_flags = md->ol_flags;
    mi->packet_type = md->packet_type;

   rte_memcpy(rte_pktmbuf_mtod(mi, char *), rte_pktmbuf_mtod(md, char *),
   *prev = mi;
   prev = &mi->next;
} while ((md = md->next) != NULL);

*prev = NULL;
return mc;



*Reference:*  http://patchwork.dpdk.org/patch/6289/

Thanks & Best Regards,

Wajeeha Javed

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