target/linux/generic/patches-3.10/110-net_fix_multiqueue_selection.patch

   1 From: Eric Dumazet <edumazet@google.com>
   2
   3 commit 416186fbf8c5b4e4465 ("net: Split core bits of netdev_pick_tx
   4 into __netdev_pick_tx") added a bug that disables caching of queue
   5 index in the socket.
   6
   7 This is the source of packet reorders for TCP flows, and
   8 again this is happening more often when using FQ pacing.
   9
  10 Old code was doing
  11
  12 if (queue_index != old_index)
  13         sk_tx_queue_set(sk, queue_index);
  14
  15 Alexander renamed the variables but forgot to change sk_tx_queue_set()
  16 2nd parameter.
  17
  18 if (queue_index != new_index)
  19         sk_tx_queue_set(sk, queue_index);
  20
  21 This means we store -1 over and over in sk->sk_tx_queue_mapping
  22
  23 Signed-off-by: Eric Dumazet <edumazet@google.com>
  24 Cc: Alexander Duyck <alexander.h.duyck@intel.com>
  25 Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
  26
  27 ---
  28 net/core/flow_dissector.c |    2 +-
  29  1 file changed, 1 insertion(+), 1 deletion(-)
  30
  31 --- a/net/core/flow_dissector.c
  32 +++ b/net/core/flow_dissector.c
  33 @@ -347,7 +347,7 @@ u16 __netdev_pick_tx(struct net_device *
  34
  35                 if (queue_index != new_index && sk &&
  36                     rcu_access_pointer(sk->sk_dst_cache))
  37 -                       sk_tx_queue_set(sk, queue_index);
  38 +                       sk_tx_queue_set(sk, new_index);
  39
  40                 queue_index = new_index;
  41         }