Re: [PATCH net-next v3 5/9] forcedeth: implement ndo_get_stats64()API

From: Stephen Hemminger
Date: Mon Nov 14 2011 - 20:10:42 EST


On Mon, 14 Nov 2011 16:11:15 -0800
David Decotigny <david.decotigny@xxxxxxxxxx> wrote:

> This commit implements the ndo_get_stats64() API for forcedeth. Since
> these stats are being updated from different contexts (process and
> timer), this commit adds protection (locking + atomic variables).
>
> Tested:
> - 16-way SMP x86_64 ->
> RX bytes:7244556582 (7.2 GB) TX bytes:181904254 (181.9 MB)
> - pktgen + loopback: identical rx_bytes/tx_bytes and rx_packets/tx_packets
>
>
>
> Signed-off-by: David Decotigny <david.decotigny@xxxxxxxxxx>
> ---
> drivers/net/ethernet/nvidia/forcedeth.c | 182 ++++++++++++++++++++++++-------
> 1 files changed, 141 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
> index ee8cce5..a67c1f4 100644
> --- a/drivers/net/ethernet/nvidia/forcedeth.c
> +++ b/drivers/net/ethernet/nvidia/forcedeth.c
> @@ -692,6 +692,21 @@ struct nv_ethtool_stats {
> #define NV_DEV_STATISTICS_V2_COUNT (NV_DEV_STATISTICS_V3_COUNT - 3)
> #define NV_DEV_STATISTICS_V1_COUNT (NV_DEV_STATISTICS_V2_COUNT - 6)
>
> +/* driver statistics */
> +struct nv_driver_stat {
> + atomic_t delta; /* increase since last nv_update_stats() */
> + u64 total; /* cumulative, requires netdev_priv(dev)->stats_lock */
> +};

Please existing u64_stats_sync rather than inventing your own
method. The u64_stats_sync is faster and does require locking.
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