From f78bd13027d9d43a6f5f3469377cd6bfd4218a14 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Tue, 25 Aug 2020 13:35:54 +0200 Subject: [PATCH] i40e, xsk: remove HW descriptor prefetch in AF_XDP path MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The software prefetching of HW descriptors has a negative impact on the performance. Therefore, it is now removed. Performance for the rx_drop benchmark increased with 2%. Signed-off-by: Björn Töpel Tested-by: Aaron Brown Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 13 +++++++++++++ drivers/net/ethernet/intel/i40e/i40e_txrx_common.h | 13 ------------- drivers/net/ethernet/intel/i40e/i40e_xsk.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 8500e1c1a16b..b43bc20f701d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2295,6 +2295,19 @@ void i40e_finalize_xdp_rx(struct i40e_ring *rx_ring, unsigned int xdp_res) } } +/** + * i40e_inc_ntc: Advance the next_to_clean index + * @rx_ring: Rx ring + **/ +static void i40e_inc_ntc(struct i40e_ring *rx_ring) +{ + u32 ntc = rx_ring->next_to_clean + 1; + + ntc = (ntc < rx_ring->count) ? ntc : 0; + rx_ring->next_to_clean = ntc; + prefetch(I40E_RX_DESC(rx_ring, ntc)); +} + /** * i40e_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf * @rx_ring: rx descriptor ring to transact packets on diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h b/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h index 667c4dc4b39f..1397dd3c1c57 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h @@ -99,19 +99,6 @@ static inline bool i40e_rx_is_programming_status(u64 qword1) return qword1 & I40E_RXD_QW1_LENGTH_SPH_MASK; } -/** - * i40e_inc_ntc: Advance the next_to_clean index - * @rx_ring: Rx ring - **/ -static inline void i40e_inc_ntc(struct i40e_ring *rx_ring) -{ - u32 ntc = rx_ring->next_to_clean + 1; - - ntc = (ntc < rx_ring->count) ? ntc : 0; - rx_ring->next_to_clean = ntc; - prefetch(I40E_RX_DESC(rx_ring, ntc)); -} - void i40e_xsk_clean_rx_ring(struct i40e_ring *rx_ring); void i40e_xsk_clean_tx_ring(struct i40e_ring *tx_ring); bool i40e_xsk_any_rx_ring_enabled(struct i40e_vsi *vsi); diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index 2a1153d8957b..cf48758447c2 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -257,6 +257,18 @@ static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring, return skb; } +/** + * i40e_inc_ntc: Advance the next_to_clean index + * @rx_ring: Rx ring + **/ +static void i40e_inc_ntc(struct i40e_ring *rx_ring) +{ + u32 ntc = rx_ring->next_to_clean + 1; + + ntc = (ntc < rx_ring->count) ? ntc : 0; + rx_ring->next_to_clean = ntc; +} + /** * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring * @rx_ring: Rx ring -- 2.17.1