Subject: Re: [PATCH net v2 1/8] forcedeth: Improve stats counters

From: Stephen Hemminger <[email-masked]>
Date: Fri, 4 Nov 2011 07:54:14 -0700

On Thu,  3 Nov 2011 18:41:16 -0700
David Decotigny <[email-masked]> wrote:

> From: Mandeep Baines <[email-masked]>
> 
> Rx byte count was off; instead use the hardware's count.  Tx packet
> count was counting pre-TSO packets; instead count on-the-wire packets.
> Report hardware dropped frame count as rx_fifo_errors.
> 
> - The count of transmitted packets reported by the forcedeth driver
>   reports pre-TSO (TCP Segmentation Offload) packet counts and not the
>   count of the number of packets sent on the wire. This change fixes
>   the forcedeth driver to report the correct count. Fixed the code by
>   copying the count stored in the NIC H/W to the value reported by the
>   driver.
> 
> - Count rx_drop_frame errors as rx_fifo_errors:
>   We see a lot of rx_drop_frame errors if we disable the rx bottom-halves
>   for too long.  Normally, rx_fifo_errors would be counted in this case.
>   The rx_drop_frame error count is private to forcedeth and is not
>   reported by ifconfig or sysfs.  The rx_fifo_errors count is currently
>   unused in the forcedeth driver.  It is reported by ifconfig as overruns.
>   This change reports rx_drop_frame errors as rx_fifo_errors.
> 
> 
> 
> Signed-off-by: David Decotigny <[email-masked]>
> ---
>  drivers/net/ethernet/nvidia/forcedeth.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
> index 1e37eb9..64b1c7c 100644
> --- a/drivers/net/ethernet/nvidia/forcedeth.c
> +++ b/drivers/net/ethernet/nvidia/forcedeth.c
> @@ -1682,6 +1682,7 @@ static void nv_get_hw_stats(struct net_device *dev)
>  		np->estats.tx_pause += readl(base + NvRegTxPause);
>  		np->estats.rx_pause += readl(base + NvRegRxPause);
>  		np->estats.rx_drop_frame += readl(base + NvRegRxDropFrame);
> +		np->estats.rx_errors_total += np->estats.rx_drop_frame;
>  	}
>  
>  	if (np->driver_data & DEV_HAS_STATISTICS_V3) {
> @@ -1706,11 +1707,14 @@ static struct net_device_stats *nv_get_stats(struct net_device *dev)
>  		nv_get_hw_stats(dev);
>  
>  		/* copy to net_device stats */
> +		dev->stats.tx_packets = np->estats.tx_packets;
> +		dev->stats.rx_bytes = np->estats.rx_bytes;
>  		dev->stats.tx_bytes = np->estats.tx_bytes;
>  		dev->stats.tx_fifo_errors = np->estats.tx_fifo_errors;
>  		dev->stats.tx_carrier_errors = np->estats.tx_carrier_errors;
>  		dev->stats.rx_crc_errors = np->estats.rx_crc_errors;
>  		dev->stats.rx_over_errors = np->estats.rx_over_errors;
> +		dev->stats.rx_fifo_errors = np->estats.rx_drop_frame;
>  		dev->stats.rx_errors = np->estats.rx_errors_total;
>  		dev->stats.tx_errors = np->estats.tx_errors_total;
>  	}

Why not convert it to 64 bit stats as well.