napi_build_skb() reuses NAPI skbuff_head cache in order to save some
cycles on freeing/allocating skbuff_heads on every new Rx or completed
Tx.
Use napi_consume_skb() to feed the cache with skbuff_heads of completed
Tx so it's never empty.

Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/bcm63xx_enet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 698438a2ee0f..514d61dd91c7 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -388,7 +388,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
 					 priv->rx_buf_size, DMA_FROM_DEVICE);
 			priv->rx_buf[desc_idx] = NULL;
 
-			skb = build_skb(buf, priv->rx_frag_size);
+			skb = napi_build_skb(buf, priv->rx_frag_size);
 			if (unlikely(!skb)) {
 				skb_free_frag(buf);
 				dev->stats.rx_dropped++;
@@ -468,7 +468,7 @@ static int bcm_enet_tx_reclaim(struct net_device *dev, int force)
 			dev->stats.tx_errors++;
 
 		bytes += skb->len;
-		dev_kfree_skb(skb);
+		napi_consume_skb(skb, !force);
 		released++;
 	}
 
-- 
2.17.1

Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Wed, 15 Jun 2022 14:09:22 +0800 you wrote:
> napi_build_skb() reuses NAPI skbuff_head cache in order to save some
> cycles on freeing/allocating skbuff_heads on every new Rx or completed
> Tx.
> Use napi_consume_skb() to feed the cache with skbuff_heads of completed
> Tx so it's never empty.
> 
> Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> [...]

Here is the summary with links:
  - [V2] bcm63xx_enet: switch to napi_build_skb() to reuse skbuff_heads
    https://git.kernel.org/netdev/net-next/c/c63c615e22eb

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

NAPI poll() function may be passed a budget value of zero, i.e. during
netpoll, which isn't NAPI context.
Therefore, napi_consume_skb() must be given budget value instead of
!force to truly discern netpoll-like scenarios.

Fixes: c63c615e22eb ("bcm63xx_enet: switch to napi_build_skb() to reuse skbuff_heads")
Signed-off-by: Sieng-Piaw Liew <liew.s.piaw@gmail.com>
---
 drivers/net/ethernet/broadcom/bcm63xx_enet.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 514d61dd91c7..193dc1db0f4e 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -423,7 +423,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget)
 /*
  * try to or force reclaim of transmitted buffers
  */
-static int bcm_enet_tx_reclaim(struct net_device *dev, int force)
+static int bcm_enet_tx_reclaim(struct net_device *dev, int force, int budget)
 {
 	struct bcm_enet_priv *priv;
 	unsigned int bytes;
@@ -468,7 +468,7 @@ static int bcm_enet_tx_reclaim(struct net_device *dev, int force)
 			dev->stats.tx_errors++;
 
 		bytes += skb->len;
-		napi_consume_skb(skb, !force);
+		napi_consume_skb(skb, budget);
 		released++;
 	}
 
@@ -499,7 +499,7 @@ static int bcm_enet_poll(struct napi_struct *napi, int budget)
 			 ENETDMAC_IR, priv->tx_chan);
 
 	/* reclaim sent skb */
-	bcm_enet_tx_reclaim(dev, 0);
+	bcm_enet_tx_reclaim(dev, 0, budget);
 
 	spin_lock(&priv->rx_lock);
 	rx_work_done = bcm_enet_receive_queue(dev, budget);
@@ -1211,7 +1211,7 @@ static int bcm_enet_stop(struct net_device *dev)
 	bcm_enet_disable_mac(priv);
 
 	/* force reclaim of all tx buffers */
-	bcm_enet_tx_reclaim(dev, 1);
+	bcm_enet_tx_reclaim(dev, 1, 0);
 
 	/* free the rx buffer ring */
 	bcm_enet_free_rx_buf_ring(kdev, priv);
@@ -2362,7 +2362,7 @@ static int bcm_enetsw_stop(struct net_device *dev)
 	bcm_enet_disable_dma(priv, priv->rx_chan);
 
 	/* force reclaim of all tx buffers */
-	bcm_enet_tx_reclaim(dev, 1);
+	bcm_enet_tx_reclaim(dev, 1, 0);
 
 	/* free the rx buffer ring */
 	bcm_enet_free_rx_buf_ring(kdev, priv);
-- 
2.17.1

Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  8 Jul 2022 16:03:03 +0800 you wrote:
> NAPI poll() function may be passed a budget value of zero, i.e. during
> netpoll, which isn't NAPI context.
> Therefore, napi_consume_skb() must be given budget value instead of
> !force to truly discern netpoll-like scenarios.
> 
> Fixes: c63c615e22eb ("bcm63xx_enet: switch to napi_build_skb() to reuse skbuff_heads")
> Signed-off-by: Sieng-Piaw Liew <liew.s.piaw@gmail.com>
> 
> [...]

Here is the summary with links:
  - bcm63xx: fix Tx cleanup when NAPI poll budget is zero
    https://git.kernel.org/netdev/net-next/c/10c8fd2f7a40

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html