Commit 7e2698c4 authored by Igor Russkikh's avatar Igor Russkikh Committed by David S. Miller
Browse files

net: aquantia: optimize rx path using larger preallocated skb len 



Atlantic driver used 14 bytes preallocated skb size. That made L3 protocol
processing inefficient because pskb_pull had to fetch all the L3/L4 headers
from extra fragments.

Specially on UDP flows that caused extra packet drops because CPU was
overloaded with pskb_pull.

This patch uses eth_get_headlen for skb preallocation.

Signed-off-by: default avatarIgor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d64fee0a

drivers/net/ethernet/aquantia/atlantic/aq_cfg.h

+2 −0
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ 


#define AQ_CFG_TX_CLEAN_BUDGET 256U



#define AQ_CFG_RX_HDR_SIZE 256U



/* LRO */

#define AQ_CFG_IS_LRO_DEF           1U

drivers/net/ethernet/aquantia/atlantic/aq_ring.c

+18 −9
Original line number Diff line number Diff line
@@ -201,17 +201,18 @@ int aq_ring_rx_clean(struct aq_ring_s *self, 
		     int budget)

{

	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);

	int err = 0;

	bool is_rsc_completed = true;

	int err = 0;



	for (; (self->sw_head != self->hw_head) && budget;

		self->sw_head = aq_ring_next_dx(self, self->sw_head),

		--budget, ++(*work_done)) {

		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];

		struct aq_ring_buff_s *buff_ = NULL;

		struct sk_buff *skb = NULL;

		unsigned int next_ = 0U;

		unsigned int i = 0U;

		struct aq_ring_buff_s *buff_ = NULL;

		u16 hdr_len;



		if (buff->is_error) {

			__free_pages(buff->page, 0);
@@ -255,20 +256,28 @@ int aq_ring_rx_clean(struct aq_ring_s *self, 
				err = -ENOMEM;

				goto err_exit;

			}



			skb_put(skb, buff->len);

		} else {

			skb = netdev_alloc_skb(ndev, ETH_HLEN);

			skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);

			if (unlikely(!skb)) {

				err = -ENOMEM;

				goto err_exit;

			}

			skb_put(skb, ETH_HLEN);

			memcpy(skb->data, page_address(buff->page), ETH_HLEN);



			skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,

					buff->len - ETH_HLEN,

					SKB_TRUESIZE(buff->len - ETH_HLEN));

			hdr_len = buff->len;

			if (hdr_len > AQ_CFG_RX_HDR_SIZE)

				hdr_len = eth_get_headlen(page_address(buff->page),

							  AQ_CFG_RX_HDR_SIZE);



			memcpy(__skb_put(skb, hdr_len), page_address(buff->page),

			       ALIGN(hdr_len, sizeof(long)));



			if (buff->len - hdr_len > 0) {

				skb_add_rx_frag(skb, 0, buff->page,

						hdr_len,

						buff->len - hdr_len,

						SKB_TRUESIZE(buff->len - hdr_len));

			}



			if (!buff->is_eop) {

				for (i = 1U, next_ = buff->next,

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