[PATCH net-next 1/1] i40e: remove dead stores on XSK hotpath

[PATCH net-next 1/1] i40e: remove dead stores on XSK hotpath

[Tony Nguyen]

From: Alexander Lobakin <alexandr.lobakin@intel.com>

The 'if (ntu == rx_ring->count)' block in i40e_alloc_rx_buffers_zc()
was previously residing in the loop, but after introducing the
batched interface it is used only to wrap-around the NTU descriptor,
thus no more need to assign 'xdp'.

'cleaned_count' in i40e_clean_rx_irq_zc() was previously being
incremented in the loop, but after commit f12738b6ec06
("i40e: remove unnecessary cleaned_count updates") it gets
assigned only once after it, so the initialization can be dropped.

Fixes: 6aab0bb0c5cd ("i40e: Use the xsk batched rx allocation interface")
Fixes: f12738b6ec06 ("i40e: remove unnecessary cleaned_count updates")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 5a997b0d07d8..c1d25b0b0ca2 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -218,7 +218,6 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
 	ntu += nb_buffs;
 	if (ntu == rx_ring->count) {
 		rx_desc = I40E_RX_DESC(rx_ring, 0);
-		xdp = i40e_rx_bi(rx_ring, 0);
 		ntu = 0;
 	}
 
@@ -328,11 +327,11 @@ static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
 int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
 {
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
-	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
 	u16 next_to_clean = rx_ring->next_to_clean;
 	u16 count_mask = rx_ring->count - 1;
 	unsigned int xdp_res, xdp_xmit = 0;
 	bool failure = false;
+	u16 cleaned_count;
 
 	while (likely(total_rx_packets < (unsigned int)budget)) {
 		union i40e_rx_desc *rx_desc;
-- 
2.31.1

Re: [PATCH net-next 1/1] i40e: remove dead stores on XSK hotpath

[patchwork-bot+netdevbpf]

Hello:

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

On Fri, 18 Feb 2022 13:50:33 -0800 you wrote:
> From: Alexander Lobakin <alexandr.lobakin@intel.com>
> 
> The 'if (ntu == rx_ring->count)' block in i40e_alloc_rx_buffers_zc()
> was previously residing in the loop, but after introducing the
> batched interface it is used only to wrap-around the NTU descriptor,
> thus no more need to assign 'xdp'.
> 
> [...]

Here is the summary with links:
  - [net-next,1/1] i40e: remove dead stores on XSK hotpath
    https://git.kernel.org/netdev/net-next/c/7e1b54d07751

You are awesome, thank you!
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