dpdk/dpdk-2.2.0_patches/0021-enic-fix-TX-hang-when-number-of-packets-queue-size.patch

   1 From e89ea2a038987102d9eb0a7ea217d7a301b484cb Mon Sep 17 00:00:00 2001
   2 From: John Daley <johndale@cisco.com>
   3 Date: Thu, 24 Mar 2016 14:00:39 -0700
   4 Subject: [PATCH 21/22]     enic: fix TX hang when number of packets > queue
   5  size
   6
   7     If the nb_pkts parameter to rte_eth_tx_burst() was greater than
   8     the TX descriptor count, a completion was not being requested
   9     from the NIC, so descriptors would not be released back to the
  10     host causing a lock-up.
  11
  12     Introduce a limit of how many TX descriptors can be used in a single
  13     call to the enic PMD burst TX function before requesting a completion.
  14
  15     Fixes: d739ba4c6abf ("enic: improve Tx packet rate")
  16
  17     Signed-off-by: John Daley <johndale@cisco.com>
  18 ---
  19  drivers/net/enic/enic_ethdev.c | 20 ++++++++++++++++----
  20  drivers/net/enic/enic_res.h    |  1 +
  21  2 files changed, 17 insertions(+), 4 deletions(-)
  22
  23 diff --git a/drivers/net/enic/enic_ethdev.c b/drivers/net/enic/enic_ethdev.c
  24 index 6c3c734..61bb83c 100644
  25 --- a/drivers/net/enic/enic_ethdev.c
  26 +++ b/drivers/net/enic/enic_ethdev.c
  27 @@ -510,7 +510,7 @@ static void enicpmd_remove_mac_addr(struct rte_eth_dev *eth_dev, __rte_unused ui
  28  static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  29         uint16_t nb_pkts)
  30  {
  31 -       unsigned int index;
  32 +       uint16_t index;
  33         unsigned int frags;
  34         unsigned int pkt_len;
  35         unsigned int seg_len;
  36 @@ -522,6 +522,7 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  37         unsigned short vlan_id;
  38         unsigned short ol_flags;
  39         uint8_t last_seg, eop;
  40 +       unsigned int host_tx_descs = 0;
  41
  42         for (index = 0; index < nb_pkts; index++) {
  43                 tx_pkt = *tx_pkts++;
  44 @@ -537,6 +538,7 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  45                                 return index;
  46                         }
  47                 }
  48 +
  49                 pkt_len = tx_pkt->pkt_len;
  50                 vlan_id = tx_pkt->vlan_tci;
  51                 ol_flags = tx_pkt->ol_flags;
  52 @@ -546,9 +548,19 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
  53                         next_tx_pkt = tx_pkt->next;
  54                         seg_len = tx_pkt->data_len;
  55                         inc_len += seg_len;
  56 -                       eop = (pkt_len == inc_len) || (!next_tx_pkt);
  57 -                       last_seg = eop &&
  58 -                               (index == ((unsigned int)nb_pkts - 1));
  59 +
  60 +                       host_tx_descs++;
  61 +                       last_seg = 0;
  62 +                       eop = 0;
  63 +                       if ((pkt_len == inc_len) || !next_tx_pkt) {
  64 +                               eop = 1;
  65 +                               /* post if last packet in batch or > thresh */
  66 +                               if ((index == (nb_pkts - 1)) ||
  67 +                                  (host_tx_descs > ENIC_TX_POST_THRESH)) {
  68 +                                       last_seg = 1;
  69 +                                       host_tx_descs = 0;
  70 +                               }
  71 +                       }
  72                         enic_send_pkt(enic, wq, tx_pkt, (unsigned short)seg_len,
  73                                       !frags, eop, last_seg, ol_flags, vlan_id);
  74                         tx_pkt = next_tx_pkt;
  75 diff --git a/drivers/net/enic/enic_res.h b/drivers/net/enic/enic_res.h
  76 index 33f2e84..00fa71d 100644
  77 --- a/drivers/net/enic/enic_res.h
  78 +++ b/drivers/net/enic/enic_res.h
  79 @@ -53,6 +53,7 @@
  80
  81  #define ENIC_NON_TSO_MAX_DESC          16
  82  #define ENIC_DEFAULT_RX_FREE_THRESH    32
  83 +#define ENIC_TX_POST_THRESH            (ENIC_MIN_WQ_DESCS / 2)
  84
  85  #define ENIC_SETTING(enic, f) ((enic->config.flags & VENETF_##f) ? 1 : 0)
  86
  87 --
  88 1.9.1
  89