On 2020-09-07 21:32, Jakub Kicinski wrote:
On Mon, 7 Sep 2020 17:02:17 +0200 Björn Töpel wrote:
From: Björn Töpel <bjorn.topel@xxxxxxxxx>
Start using XSK_NAPI_WEIGHT as NAPI poll budget for the AF_XDP Rx
zero-copy path.
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
index 3771857cf887..f32c1ba0d237 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
@@ -239,7 +239,7 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
bool failure = false;
struct sk_buff *skb;
- while (likely(total_rx_packets < budget)) {
+ while (likely(total_rx_packets < XSK_NAPI_WEIGHT)) {
I was thinking that we'd multiply 'budget' here, not replace it with a
constant. Looks like ixgbe dutifully passes 'per_ring_budget' into the
clean_rx functions, not a complete NAPI budget.
Correct, and i40e/ice does the same ("per_ring_budget").
As for budget << XSK_NAPI_MULT vs replacing; Replacing the budget is
more in line with what the drivers do for the Tx cleanup
(xxx_clean_tx_irq), where the napi budget is discarded completely;
Again, with the idea that "this is much cheaper than a "per-packet
through the stack".
Do you prefer the multiplier way that you describe?
Cheers,
Björn
union ixgbe_adv_rx_desc *rx_desc;
struct ixgbe_rx_buffer *bi;
unsigned int size;
