[PATCH net-next v2 3/3] i40e, xsk: move buffer allocation out of the Rx processing loop

[Björn Töpel]

From: Björn Töpel <bjorn.to...@intel.com>

Instead of checking in each iteration of the Rx packet processing
loop, move the allocation out of the loop and do it once for each napi
activation.

For AF_XDP the rx_drop benchmark was improved by 6%.

Signed-off-by: Björn Töpel <bjorn.to...@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c 
b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 1f2dd591dbf1..ae40592c31f9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -277,8 +277,8 @@ 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);
        unsigned int xdp_res, xdp_xmit = 0;
-       bool failure = false;
        struct sk_buff *skb;
+       bool failure;
 
        while (likely(total_rx_packets < (unsigned int)budget)) {
                union i40e_rx_desc *rx_desc;
@@ -286,13 +286,6 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int 
budget)
                unsigned int size;
                u64 qword;
 
-               if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
-                       failure = failure ||
-                                 !i40e_alloc_rx_buffers_zc(rx_ring,
-                                                           cleaned_count);
-                       cleaned_count = 0;
-               }
-
                rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
                qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
 
@@ -367,6 +360,9 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int 
budget)
                napi_gro_receive(&rx_ring->q_vector->napi, skb);
        }
 
+       if (cleaned_count >= I40E_RX_BUFFER_WRITE)
+               failure = !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
+
        i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
        i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
 
-- 
2.25.1