[net-next,v3] e1000e: Be drop monitor friendly

e1000e_put_txbuf() can be called from normal reclamation path as well as
when a DMA mapping failure, so we need to differentiate these two cases
when freeing SKBs to be drop monitor friendly. e1000e_tx_hwtstamp_work()
and e1000_remove() are processing TX timestamped SKBs and those should
not be accounted as drops either.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Changes in v3:

- differentiate normal reclamation from TX DMA fragment mapping errors
- removed a few invalid dev_kfree_skb() replacements (those are already
  drop monitor friendly)

Changes in v2:

- make it compile

 drivers/net/ethernet/intel/e1000e/netdev.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

On 8/26/2017 04:14, Florian Fainelli wrote:
> e1000e_put_txbuf() can be called from normal reclamation path as well as
> when a DMA mapping failure, so we need to differentiate these two cases
> when freeing SKBs to be drop monitor friendly. e1000e_tx_hwtstamp_work()
> and e1000_remove() are processing TX timestamped SKBs and those should
> not be accounted as drops either.
>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> Changes in v3:
>
> - differentiate normal reclamation from TX DMA fragment mapping errors
> - removed a few invalid dev_kfree_skb() replacements (those are already
>    drop monitor friendly)
>
> Changes in v2:
>
> - make it compile
>
>   drivers/net/ethernet/intel/e1000e/netdev.c | 18 +++++++++++-------
>   1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 327dfe5bedc0..cfd21858c095 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1071,7 +1071,8 @@ static bool e1000_clean_rx_irq(struct e1000_ring *rx_ring, int *work_done,
>   }
>   
>   static void e1000_put_txbuf(struct e1000_ring *tx_ring,
> -			    struct e1000_buffer *buffer_info)
> +			    struct e1000_buffer *buffer_info,
> +			    bool drop)
>   {
>   	struct e1000_adapter *adapter = tx_ring->adapter;
>   
> @@ -1085,7 +1086,10 @@ static void e1000_put_txbuf(struct e1000_ring *tx_ring,
>   		buffer_info->dma = 0;
>   	}
>   	if (buffer_info->skb) {
> -		dev_kfree_skb_any(buffer_info->skb);
> +		if (drop)
> +			dev_kfree_skb_any(buffer_info->skb);
> +		else
> +			dev_consume_skb_any(buffer_info->skb);
>   		buffer_info->skb = NULL;
>   	}
>   	buffer_info->time_stamp = 0;
> @@ -1199,7 +1203,7 @@ static void e1000e_tx_hwtstamp_work(struct work_struct *work)
>   		wmb(); /* force write prior to skb_tstamp_tx */
>   
>   		skb_tstamp_tx(skb, &shhwtstamps);
> -		dev_kfree_skb_any(skb);
> +		dev_consume_skb_any(skb);
>   	} else if (time_after(jiffies, adapter->tx_hwtstamp_start
>   			      + adapter->tx_timeout_factor * HZ)) {
>   		dev_kfree_skb_any(adapter->tx_hwtstamp_skb);
> @@ -1254,7 +1258,7 @@ static bool e1000_clean_tx_irq(struct e1000_ring *tx_ring)
>   				}
>   			}
>   
> -			e1000_put_txbuf(tx_ring, buffer_info);
> +			e1000_put_txbuf(tx_ring, buffer_info, false);
>   			tx_desc->upper.data = 0;
>   
>   			i++;
> @@ -2421,7 +2425,7 @@ static void e1000_clean_tx_ring(struct e1000_ring *tx_ring)
>   
>   	for (i = 0; i < tx_ring->count; i++) {
>   		buffer_info = &tx_ring->buffer_info[i];
> -		e1000_put_txbuf(tx_ring, buffer_info);
> +		e1000_put_txbuf(tx_ring, buffer_info, false);
>   	}
>   
>   	netdev_reset_queue(adapter->netdev);
> @@ -5614,7 +5618,7 @@ static int e1000_tx_map(struct e1000_ring *tx_ring, struct sk_buff *skb,
>   			i += tx_ring->count;
>   		i--;
>   		buffer_info = &tx_ring->buffer_info[i];
> -		e1000_put_txbuf(tx_ring, buffer_info);
> +		e1000_put_txbuf(tx_ring, buffer_info, true);
>   	}
>   
>   	return 0;
> @@ -7411,7 +7415,7 @@ static void e1000_remove(struct pci_dev *pdev)
>   	if (adapter->flags & FLAG_HAS_HW_TIMESTAMP) {
>   		cancel_work_sync(&adapter->tx_hwtstamp_work);
>   		if (adapter->tx_hwtstamp_skb) {
> -			dev_kfree_skb_any(adapter->tx_hwtstamp_skb);
> +			dev_consume_skb_any(adapter->tx_hwtstamp_skb);
>   			adapter->tx_hwtstamp_skb = NULL;
>   		}
>   	}

i am ok with this patch

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On Behalf
> Of Florian Fainelli
> Sent: Friday, August 25, 2017 6:14 PM
> To: netdev@vger.kernel.org
> Cc: edumazet@gmail.com; Florian Fainelli <f.fainelli@gmail.com>; open list
> <linux-kernel@vger.kernel.org>; moderated list:INTEL ETHERNET DRIVERS
> <intel-wired-lan@lists.osuosl.org>; davem@davemloft.net
> Subject: [Intel-wired-lan] [PATCH net-next v3] e1000e: Be drop monitor
> friendly
> 
> e1000e_put_txbuf() can be called from normal reclamation path as well as
> when a DMA mapping failure, so we need to differentiate these two cases
> when freeing SKBs to be drop monitor friendly. e1000e_tx_hwtstamp_work()
> and e1000_remove() are processing TX timestamped SKBs and those should
> not be accounted as drops either.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> Changes in v3:
> 
> - differentiate normal reclamation from TX DMA fragment mapping errors
> - removed a few invalid dev_kfree_skb() replacements (those are already
>   drop monitor friendly)
> 
> Changes in v2:
> 
> - make it compile
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)

Tested-by: Aaron Brown <aaron.f.brown@intel.com>