• Jesper Dangaard Brouer's avatar
    igb: Record host memory receive overflow in net_stats · 3ea73afa
    Jesper Dangaard Brouer authored
    Based on previous patch from Jesper Dangaard Brouer.
    
    The RNBC (Receive No Buffers Count) register for the 82576, indicate
    that frames were received when there were no available buffers in host
    memory to store those frames (receive descriptor head and tail
    pointers were equal).  The packet is still received by the NIC if
    there is space in the FIFO on the NIC.
    
    As the RNBC value is not a packet drop, the driver stores this value
    in net_stats.rx_fifo_errors to indicate that there were no system
    buffers available for the incoming packet.  Actual dropped packets
    are counted in the MPC value.
    
    Saving the stats in dev->net_stats makes it visible via
    /proc/net/dev as "fifo", and thus viewable to ifconfig
    as "overruns" and 'netstat -i' as "RX-OVR".
    
    The Receive No Buffers Count (RNBC) can already be queried by
    ethtool -S as "rx_no_buffer_count".
    Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
    CC: Jesper Dangaard Brouer <hawk@comx.dk>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    3ea73afa
igb_main.c 150 KB