提交 1d2024f6 编写于 作者: A Alexander Duyck 提交者: Jeff Kirsher

ixgbe: Address fact that RSC was not setting GSO size for incoming frames

This patch is meant to address the fact that RSC has not been setting the
gso_size value on the skb.  As a result performance on lossy TCP
connections was negatively impacted.  This change resolves the issue by
setting gso_size to the average size for incoming packets.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NStephen Ko <stephen.s.ko@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
上级 4c1975d7
......@@ -1276,6 +1276,104 @@ static inline bool ixgbe_close_active_frag_list(struct sk_buff *head)
return true;
}
/**
* ixgbe_get_headlen - determine size of header for RSC/LRO/GRO/FCOE
* @data: pointer to the start of the headers
* @max_len: total length of section to find headers in
*
* This function is meant to determine the length of headers that will
* be recognized by hardware for LRO, GRO, and RSC offloads. The main
* motivation of doing this is to only perform one pull for IPv4 TCP
* packets so that we can do basic things like calculating the gso_size
* based on the average data per packet.
**/
static unsigned int ixgbe_get_headlen(unsigned char *data,
unsigned int max_len)
{
union {
unsigned char *network;
/* l2 headers */
struct ethhdr *eth;
struct vlan_hdr *vlan;
/* l3 headers */
struct iphdr *ipv4;
} hdr;
__be16 protocol;
u8 nexthdr = 0; /* default to not TCP */
u8 hlen;
/* this should never happen, but better safe than sorry */
if (max_len < ETH_HLEN)
return max_len;
/* initialize network frame pointer */
hdr.network = data;
/* set first protocol and move network header forward */
protocol = hdr.eth->h_proto;
hdr.network += ETH_HLEN;
/* handle any vlan tag if present */
if (protocol == __constant_htons(ETH_P_8021Q)) {
if ((hdr.network - data) > (max_len - VLAN_HLEN))
return max_len;
protocol = hdr.vlan->h_vlan_encapsulated_proto;
hdr.network += VLAN_HLEN;
}
/* handle L3 protocols */
if (protocol == __constant_htons(ETH_P_IP)) {
if ((hdr.network - data) > (max_len - sizeof(struct iphdr)))
return max_len;
/* access ihl as a u8 to avoid unaligned access on ia64 */
hlen = (hdr.network[0] & 0x0F) << 2;
/* verify hlen meets minimum size requirements */
if (hlen < sizeof(struct iphdr))
return hdr.network - data;
/* record next protocol */
nexthdr = hdr.ipv4->protocol;
hdr.network += hlen;
#ifdef CONFIG_FCOE
} else if (protocol == __constant_htons(ETH_P_FCOE)) {
if ((hdr.network - data) > (max_len - FCOE_HEADER_LEN))
return max_len;
hdr.network += FCOE_HEADER_LEN;
#endif
} else {
return hdr.network - data;
}
/* finally sort out TCP */
if (nexthdr == IPPROTO_TCP) {
if ((hdr.network - data) > (max_len - sizeof(struct tcphdr)))
return max_len;
/* access doff as a u8 to avoid unaligned access on ia64 */
hlen = (hdr.network[12] & 0xF0) >> 2;
/* verify hlen meets minimum size requirements */
if (hlen < sizeof(struct tcphdr))
return hdr.network - data;
hdr.network += hlen;
}
/*
* If everything has gone correctly hdr.network should be the
* data section of the packet and will be the end of the header.
* If not then it probably represents the end of the last recognized
* header.
*/
if ((hdr.network - data) < max_len)
return hdr.network - data;
else
return max_len;
}
static void ixgbe_get_rsc_cnt(struct ixgbe_ring *rx_ring,
union ixgbe_adv_rx_desc *rx_desc,
struct sk_buff *skb)
......@@ -1299,6 +1397,32 @@ static void ixgbe_get_rsc_cnt(struct ixgbe_ring *rx_ring,
IXGBE_CB(skb)->append_cnt += rsc_cnt - 1;
}
static void ixgbe_set_rsc_gso_size(struct ixgbe_ring *ring,
struct sk_buff *skb)
{
u16 hdr_len = ixgbe_get_headlen(skb->data, skb_headlen(skb));
/* set gso_size to avoid messing up TCP MSS */
skb_shinfo(skb)->gso_size = DIV_ROUND_UP((skb->len - hdr_len),
IXGBE_CB(skb)->append_cnt);
}
static void ixgbe_update_rsc_stats(struct ixgbe_ring *rx_ring,
struct sk_buff *skb)
{
/* if append_cnt is 0 then frame is not RSC */
if (!IXGBE_CB(skb)->append_cnt)
return;
rx_ring->rx_stats.rsc_count += IXGBE_CB(skb)->append_cnt;
rx_ring->rx_stats.rsc_flush++;
ixgbe_set_rsc_gso_size(rx_ring, skb);
/* gso_size is computed using append_cnt so always clear it last */
IXGBE_CB(skb)->append_cnt = 0;
}
static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
struct ixgbe_ring *rx_ring,
int budget)
......@@ -1437,11 +1561,7 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
goto next_desc;
}
if (IXGBE_CB(skb)->append_cnt) {
rx_ring->rx_stats.rsc_count +=
IXGBE_CB(skb)->append_cnt;
rx_ring->rx_stats.rsc_flush++;
}
ixgbe_update_rsc_stats(rx_ring, skb);
/* ERR_MASK will only have valid bits if EOP set */
if (unlikely(staterr & IXGBE_RXDADV_ERR_FRAME_ERR_MASK)) {
......
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