Re: [dpdk-dev] [PATCH] vmxnet3: stats_reset implementation

[Yong Wang <yongwang@vmware.com>]

> On Sep 17, 2018, at 12:45 AM, yogev ch <yogev@cgstowernetworks.com> wrote:
> 
> 'stats_reset()' callback was missing.
> This commit implements the callback by taking a snapshot of the stats (SNAPSHOT) each time 'stats_reset()' is called.
> When getting stats with 'stats_get()', hw stats which always increase reduce SNAPSHOT stats. That's how we get the "real" stats since the last 'stats_reset()'.
> 
> Signed-off-by: yogev ch <yogev@cgstowernetworks.com>
> ---

Acked-by: Yong Wang <yongwang@vmware.com>

One nit: in the description, it will be good to mention the reason of this not supported is because the device backend doesn’t support it.  This commit adds a workaround to this by ... (what you have added).

> drivers/net/vmxnet3/vmxnet3_ethdev.c | 78 ++++++++++++++++++++++++++++++++++--
> drivers/net/vmxnet3/vmxnet3_ethdev.h |  3 ++
> 2 files changed, 78 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/vmxnet3/vmxnet3_ethdev.c b/drivers/net/vmxnet3/vmxnet3_ethdev.c
> index 2613cd1..2348300 100644
> --- a/drivers/net/vmxnet3/vmxnet3_ethdev.c
> +++ b/drivers/net/vmxnet3/vmxnet3_ethdev.c
> @@ -78,6 +78,7 @@ static int vmxnet3_dev_link_update(struct rte_eth_dev *dev,
> static void vmxnet3_hw_stats_save(struct vmxnet3_hw *hw);
> static int vmxnet3_dev_stats_get(struct rte_eth_dev *dev,
>                  struct rte_eth_stats *stats);
> +static void vmxnet3_dev_stats_reset(struct rte_eth_dev *dev);
> static int vmxnet3_dev_xstats_get_names(struct rte_eth_dev *dev,
>                    struct rte_eth_xstat_name *xstats,
>                    unsigned int n);
> @@ -120,6 +121,7 @@ static int vmxnet3_mac_addr_set(struct rte_eth_dev *dev,
>    .stats_get            = vmxnet3_dev_stats_get,
>    .xstats_get_names     = vmxnet3_dev_xstats_get_names,
>    .xstats_get           = vmxnet3_dev_xstats_get,
> +    .stats_reset          = vmxnet3_dev_stats_reset,
>    .mac_addr_set         = vmxnet3_mac_addr_set,
>    .dev_infos_get        = vmxnet3_dev_info_get,
>    .dev_supported_ptypes_get = vmxnet3_dev_supported_ptypes_get,
> @@ -335,6 +337,10 @@ struct vmxnet3_xstats_name_off {
>    memset(hw->saved_tx_stats, 0, sizeof(hw->saved_tx_stats));
>    memset(hw->saved_rx_stats, 0, sizeof(hw->saved_rx_stats));
> 
> +    /* clear snapshot stats */
> +    memset(hw->snapshot_tx_stats, 0, sizeof(hw->snapshot_tx_stats));
> +    memset(hw->snapshot_rx_stats, 0, sizeof(hw->snapshot_rx_stats));
> +
>    /* set the initial link status */
>    memset(&link, 0, sizeof(link));
>    link.link_duplex = ETH_LINK_FULL_DUPLEX;
> @@ -890,7 +896,49 @@ static int eth_vmxnet3_pci_remove(struct rte_pci_device *pci_dev)
>    VMXNET3_UPDATE_RX_STAT(hw, q, pktsRxError, res);
>    VMXNET3_UPDATE_RX_STAT(hw, q, pktsRxOutOfBuf, res);
> 
> -#undef VMXNET3_UPDATE_RX_STATS
> +#undef VMXNET3_UPDATE_RX_STAT
> +}
> +
> +static void
> +vmxnet3_tx_stats_get(struct vmxnet3_hw *hw, unsigned int q,
> +                    struct UPT1_TxStats *res)
> +{
> +        vmxnet3_hw_tx_stats_get(hw, q, res);
> +
> +#define VMXNET3_REDUCE_SNAPSHOT_TX_STAT(h, i, f, r)    \
> +        ((r)->f -= (h)->snapshot_tx_stats[(i)].f)
> +
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, ucastPktsTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, mcastPktsTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, bcastPktsTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, ucastBytesTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, mcastBytesTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, bcastBytesTxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, pktsTxError, res);
> +    VMXNET3_REDUCE_SNAPSHOT_TX_STAT(hw, q, pktsTxDiscard, res);
> +
> +#undef VMXNET3_REDUCE_SNAPSHOT_TX_STAT
> +}
> +
> +static void
> +vmxnet3_rx_stats_get(struct vmxnet3_hw *hw, unsigned int q,
> +                    struct UPT1_RxStats *res)
> +{
> +        vmxnet3_hw_rx_stats_get(hw, q, res);
> +
> +#define VMXNET3_REDUCE_SNAPSHOT_RX_STAT(h, i, f, r)    \
> +        ((r)->f -= (h)->snapshot_rx_stats[(i)].f)
> +
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, ucastPktsRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, mcastPktsRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, bcastPktsRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, ucastBytesRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, mcastBytesRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, bcastBytesRxOK, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, pktsRxError, res);
> +    VMXNET3_REDUCE_SNAPSHOT_RX_STAT(hw, q, pktsRxOutOfBuf, res);
> +
> +#undef VMXNET3_REDUCE_SNAPSHOT_RX_STAT
> }
> 
> static void
> @@ -1005,7 +1053,7 @@ static int eth_vmxnet3_pci_remove(struct rte_pci_device *pci_dev)
> 
>    RTE_BUILD_BUG_ON(RTE_ETHDEV_QUEUE_STAT_CNTRS < VMXNET3_MAX_TX_QUEUES);
>    for (i = 0; i < hw->num_tx_queues; i++) {
> -        vmxnet3_hw_tx_stats_get(hw, i, &txStats);
> +        vmxnet3_tx_stats_get(hw, i, &txStats);
> 
>        stats->q_opackets[i] = txStats.ucastPktsTxOK +
>            txStats.mcastPktsTxOK +
> @@ -1022,7 +1070,7 @@ static int eth_vmxnet3_pci_remove(struct rte_pci_device *pci_dev)
> 
>    RTE_BUILD_BUG_ON(RTE_ETHDEV_QUEUE_STAT_CNTRS < VMXNET3_MAX_RX_QUEUES);
>    for (i = 0; i < hw->num_rx_queues; i++) {
> -        vmxnet3_hw_rx_stats_get(hw, i, &rxStats);
> +        vmxnet3_rx_stats_get(hw, i, &rxStats);
> 
>        stats->q_ipackets[i] = rxStats.ucastPktsRxOK +
>            rxStats.mcastPktsRxOK +
> @@ -1044,6 +1092,30 @@ static int eth_vmxnet3_pci_remove(struct rte_pci_device *pci_dev)
> }
> 
> static void
> +vmxnet3_dev_stats_reset(struct rte_eth_dev *dev)
> +{
> +    unsigned int i;
> +    struct vmxnet3_hw *hw = dev->data->dev_private;
> +    struct UPT1_TxStats txStats;
> +    struct UPT1_RxStats rxStats;
> +
> +    VMXNET3_WRITE_BAR1_REG(hw, VMXNET3_REG_CMD, VMXNET3_CMD_GET_STATS);
> +
> +    RTE_BUILD_BUG_ON(RTE_ETHDEV_QUEUE_STAT_CNTRS < VMXNET3_MAX_TX_QUEUES);
> +
> +    for (i = 0; i < hw->num_tx_queues; i++) {
> +        vmxnet3_hw_tx_stats_get(hw, i, &txStats);
> +        memcpy(&hw->snapshot_tx_stats[i], &txStats,
> +            sizeof(hw->snapshot_tx_stats[0]));
> +    }
> +    for (i = 0; i < hw->num_rx_queues; i++) {
> +        vmxnet3_hw_rx_stats_get(hw, i, &rxStats);
> +        memcpy(&hw->snapshot_rx_stats[i], &rxStats,
> +            sizeof(hw->snapshot_rx_stats[0]));
> +    }
> +}
> +
> +static void
> vmxnet3_dev_info_get(struct rte_eth_dev *dev __rte_unused,
>             struct rte_eth_dev_info *dev_info)
> {
> diff --git a/drivers/net/vmxnet3/vmxnet3_ethdev.h b/drivers/net/vmxnet3/vmxnet3_ethdev.h
> index d3f2b35..5bc3a84 100644
> --- a/drivers/net/vmxnet3/vmxnet3_ethdev.h
> +++ b/drivers/net/vmxnet3/vmxnet3_ethdev.h
> @@ -98,6 +98,9 @@ struct vmxnet3_hw {
> #define VMXNET3_VFT_TABLE_SIZE     (VMXNET3_VFT_SIZE * sizeof(uint32_t))
>    UPT1_TxStats          saved_tx_stats[VMXNET3_MAX_TX_QUEUES];
>    UPT1_RxStats          saved_rx_stats[VMXNET3_MAX_RX_QUEUES];
> +
> +    UPT1_TxStats          snapshot_tx_stats[VMXNET3_MAX_TX_QUEUES];
> +    UPT1_RxStats          snapshot_rx_stats[VMXNET3_MAX_RX_QUEUES];
> };
> 
> #define VMXNET3_REV_3        2        /* Vmxnet3 Rev. 3 */
> -- 
> 1.9.1
>