ixgb: add RNBC counter - no buffer count - to ethtool stats

This counter is valuable to determine if the system is unable
to timely return buffers to the hardware and this counter starts
to increase well before the hardware starts to drop packets. If
users experience rx_no_buffer_count increasing, they should increase
the amount of descriptors. That will provide more buffers for the
hardware and will decrease the chance of hard drops.

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/ixgb/ixgb_ethtool.c b/drivers/net/ixgb/ixgb_ethtool.c
index 53a9fd086f960cdacd4704ee1d2d68fe0d5d181c..75f3a68ee354ef23fc33b0848fe5c3bb36e5a64b 100644 (file)
--- a/drivers/net/ixgb/ixgb_ethtool.c
+++ b/drivers/net/ixgb/ixgb_ethtool.c
@@ -67,6 +67,7 @@ static struct ixgb_stats ixgb_gstrings_stats[] = {
        {"rx_over_errors", IXGB_STAT(net_stats.rx_over_errors)},
        {"rx_crc_errors", IXGB_STAT(net_stats.rx_crc_errors)},
        {"rx_frame_errors", IXGB_STAT(net_stats.rx_frame_errors)},
+       {"rx_no_buffer_count", IXGB_STAT(stats.rnbc)},
        {"rx_fifo_errors", IXGB_STAT(net_stats.rx_fifo_errors)},
        {"rx_missed_errors", IXGB_STAT(net_stats.rx_missed_errors)},
        {"tx_aborted_errors", IXGB_STAT(net_stats.tx_aborted_errors)},