[PATCH v3 net-next 0/2] myri10ge: LRO to GRO conversion

[PATCH v3 net-next 0/2] myri10ge: LRO to GRO conversion

[Andrew Gallatin]

Hi,

The following patchset is a resubmission of '[PATCH resend net-next 0/3]
myri10ge: LRO to GRO conversion', and converts myri10ge from using
the old inet_lro interface to GRO, and to do vlan tag decap in
the driver so as to not suffer a performance penalty for vlan
tagged traffic due to the conversion.

Changes this time are:

- Clean up some messy indenting & parens in
   "2/3 myri10ge-Add-vlan-rx-for-better-GRO-perf"
   and store the vlan hdr csum in a variable, so now we are not calling
   csum_partial() nested so deeply it spreads across 3 lines

- Folded 3/3 myri10ge-Use-skb_fill_page_desc into 1/3
   myri10ge-Convert-from-LRO-to-GRO.patch since it is really just small
   part of the LRO removal cleanup.  It was originally a separate patch
   because I noticed the cleanup at the last second, and was too lazy
   to fold it into the first patch where it belonged.

Note that a naive LRO->GRO conversion of myri10ge will result in a
performance regression for vlan tagged frames.  This is because
myri10ge does not offer hardware vlan tag offload, and because GRO
requires hardware vlan tag offload to aggregate vlan tagged frames.

To address this performance regression, I have implemented vlan tag
popping in the myri10ge driver, as it seems to be the lesser of two
evils.  As eric.dumazet@gmail.com commented when I asked about this on
netdev: "Given GRO assumes NIC does hardware vlan
offloading, I guess I would chose to do that.  It seems unfortunate to
add vlan decap in GRO path, already very complex."

Andrew Gallatin (2):
myri10ge: Convert from LRO to GRO
myri10ge: Add vlan rx for better GRO perf.

  drivers/net/ethernet/myricom/Kconfig             |    1 -
  drivers/net/ethernet/myricom/myri10ge/myri10ge.c |  275 
++++++----------------
  2 files changed, 74 insertions(+), 202 deletions(-)

Re: [PATCH v3 net-next 0/2] myri10ge: LRO to GRO conversion

[David Miller]

From: Andrew Gallatin <gallatin@myri.com>
Date: Thu, 29 Nov 2012 16:07:15 -0500

> 
>  drivers/net/ethernet/myricom/Kconfig             |    1 -
>  drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 275
>  ++++++----------------
>  2 files changed, 74 insertions(+), 202 deletions(-)
> 

Your email client is chopping up long lines, corrupting your
patches.

[PATCH v3 resend net-next 0/2] myri10ge: LRO to GRO conversion

[Andrew Gallatin]

Hi,

I'm resending this after fixing email client issues.

The following patchset is a resubmission of '[PATCH resend net-next 0/3]
myri10ge: LRO to GRO conversion', and converts myri10ge from using
the old inet_lro interface to GRO, and to do vlan tag decap in
the driver so as to not suffer a performance penalty for vlan
tagged traffic due to the conversion.

Changes this time are:

- Clean up some messy indenting & parens in
  "2/3 myri10ge-Add-vlan-rx-for-better-GRO-perf"
  and store the vlan hdr csum in a variable, so now we are not calling
  csum_partial() nested so deeply it spreads across 3 lines

- Folded 3/3 myri10ge-Use-skb_fill_page_desc into 1/3
  myri10ge-Convert-from-LRO-to-GRO.patch since it is really just small
  part of the LRO removal cleanup.  It was originally a separate patch
  because I noticed the cleanup at the last second, and was too lazy
  to fold it into the first patch where it belonged.

Note that a naive LRO->GRO conversion of myri10ge will result in a
performance regression for vlan tagged frames.  This is because
myri10ge does not offer hardware vlan tag offload, and because GRO
requires hardware vlan tag offload to aggregate vlan tagged frames.

To address this performance regression, I have implemented vlan tag
popping in the myri10ge driver, as it seems to be the lesser of two
evils.  As eric.dumazet@gmail.com commented when I asked about this on
netdev: "Given GRO assumes NIC does hardware vlan
offloading, I guess I would chose to do that.  It seems unfortunate to
add vlan decap in GRO path, already very complex." 

Andrew Gallatin (2):
  myri10ge: Convert from LRO to GRO
  myri10ge: Add vlan rx for better GRO perf.

 drivers/net/ethernet/myricom/Kconfig             |    1 -
 drivers/net/ethernet/myricom/myri10ge/myri10ge.c |  275 ++++++----------------
 2 files changed, 74 insertions(+), 202 deletions(-)

-- 
1.7.9.5

[PATCH v3 resend net-next 1/2] myri10ge: Convert from LRO to GRO

[Andrew Gallatin]

Convert myri10ge from LRO to GRO, and simplify the driver by removing
various LRO-related code which is no longer needed including
ndo_fix_features op, custom skb building from frags, and LRO
header parsing.

Signed-off-by: Andrew Gallatin <gallatin@myri.com>
---
 drivers/net/ethernet/myricom/Kconfig             |    1 -
 drivers/net/ethernet/myricom/myri10ge/myri10ge.c |  236 ++++------------------
 2 files changed, 34 insertions(+), 203 deletions(-)

diff --git a/drivers/net/ethernet/myricom/Kconfig b/drivers/net/ethernet/myricom/Kconfig
index 540f0c6..3932d08 100644
--- a/drivers/net/ethernet/myricom/Kconfig
+++ b/drivers/net/ethernet/myricom/Kconfig
@@ -23,7 +23,6 @@ config MYRI10GE
 	depends on PCI && INET
 	select FW_LOADER
 	select CRC32
-	select INET_LRO
 	---help---
 	  This driver supports Myricom Myri-10G Dual Protocol interface in
 	  Ethernet mode. If the eeprom on your board is not recent enough,
diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 83516e3..84207c0 100644
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -50,7 +50,6 @@
 #include <linux/etherdevice.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
-#include <linux/inet_lro.h>
 #include <linux/dca.h>
 #include <linux/ip.h>
 #include <linux/inet.h>
@@ -96,8 +95,6 @@ MODULE_LICENSE("Dual BSD/GPL");
 
 #define MYRI10GE_EEPROM_STRINGS_SIZE 256
 #define MYRI10GE_MAX_SEND_DESC_TSO ((65536 / 2048) * 2)
-#define MYRI10GE_MAX_LRO_DESCRIPTORS 8
-#define MYRI10GE_LRO_MAX_PKTS 64
 
 #define MYRI10GE_NO_CONFIRM_DATA htonl(0xffffffff)
 #define MYRI10GE_NO_RESPONSE_RESULT 0xffffffff
@@ -165,8 +162,6 @@ struct myri10ge_rx_done {
 	dma_addr_t bus;
 	int cnt;
 	int idx;
-	struct net_lro_mgr lro_mgr;
-	struct net_lro_desc lro_desc[MYRI10GE_MAX_LRO_DESCRIPTORS];
 };
 
 struct myri10ge_slice_netstats {
@@ -338,11 +333,6 @@ static int myri10ge_debug = -1;	/* defaults above */
 module_param(myri10ge_debug, int, 0);
 MODULE_PARM_DESC(myri10ge_debug, "Debug level (0=none,...,16=all)");
 
-static int myri10ge_lro_max_pkts = MYRI10GE_LRO_MAX_PKTS;
-module_param(myri10ge_lro_max_pkts, int, S_IRUGO);
-MODULE_PARM_DESC(myri10ge_lro_max_pkts,
-		 "Number of LRO packets to be aggregated");
-
 static int myri10ge_fill_thresh = 256;
 module_param(myri10ge_fill_thresh, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(myri10ge_fill_thresh, "Number of empty rx slots allowed");
@@ -1197,36 +1187,6 @@ static inline void myri10ge_vlan_ip_csum(struct sk_buff *skb, __wsum hw_csum)
 	}
 }
 
-static inline void
-myri10ge_rx_skb_build(struct sk_buff *skb, u8 * va,
-		      struct skb_frag_struct *rx_frags, int len, int hlen)
-{
-	struct skb_frag_struct *skb_frags;
-
-	skb->len = skb->data_len = len;
-	/* attach the page(s) */
-
-	skb_frags = skb_shinfo(skb)->frags;
-	while (len > 0) {
-		memcpy(skb_frags, rx_frags, sizeof(*skb_frags));
-		len -= skb_frag_size(rx_frags);
-		skb_frags++;
-		rx_frags++;
-		skb_shinfo(skb)->nr_frags++;
-	}
-
-	/* pskb_may_pull is not available in irq context, but
-	 * skb_pull() (for ether_pad and eth_type_trans()) requires
-	 * the beginning of the packet in skb_headlen(), move it
-	 * manually */
-	skb_copy_to_linear_data(skb, va, hlen);
-	skb_shinfo(skb)->frags[0].page_offset += hlen;
-	skb_frag_size_sub(&skb_shinfo(skb)->frags[0], hlen);
-	skb->data_len -= hlen;
-	skb->tail += hlen;
-	skb_pull(skb, MXGEFW_PAD);
-}
-
 static void
 myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
 			int bytes, int watchdog)
@@ -1304,18 +1264,14 @@ myri10ge_unmap_rx_page(struct pci_dev *pdev,
 	}
 }
 
-#define MYRI10GE_HLEN 64	/* The number of bytes to copy from a
-				 * page into an skb */
-
 static inline int
-myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum,
-		 bool lro_enabled)
+myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
 {
 	struct myri10ge_priv *mgp = ss->mgp;
 	struct sk_buff *skb;
-	struct skb_frag_struct rx_frags[MYRI10GE_MAX_FRAGS_PER_FRAME];
+	struct skb_frag_struct *rx_frags;
 	struct myri10ge_rx_buf *rx;
-	int i, idx, hlen, remainder, bytes;
+	int i, idx, remainder, bytes;
 	struct pci_dev *pdev = mgp->pdev;
 	struct net_device *dev = mgp->dev;
 	u8 *va;
@@ -1332,67 +1288,47 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum,
 	idx = rx->cnt & rx->mask;
 	va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;
 	prefetch(va);
+
+	skb = napi_get_frags(&ss->napi);
+	if (unlikely(skb == NULL)) {
+		ss->stats.rx_dropped++;
+		for (i = 0, remainder = len; remainder > 0; i++) {
+			myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
+			put_page(rx->info[idx].page);
+			rx->cnt++;
+			idx = rx->cnt & rx->mask;
+			remainder -= MYRI10GE_ALLOC_SIZE;
+		}
+		return 0;
+	}
+	rx_frags = skb_shinfo(skb)->frags;
 	/* Fill skb_frag_struct(s) with data from our receive */
 	for (i = 0, remainder = len; remainder > 0; i++) {
 		myri10ge_unmap_rx_page(pdev, &rx->info[idx], bytes);
-		__skb_frag_set_page(&rx_frags[i], rx->info[idx].page);
-		rx_frags[i].page_offset = rx->info[idx].page_offset;
-		if (remainder < MYRI10GE_ALLOC_SIZE)
-			skb_frag_size_set(&rx_frags[i], remainder);
-		else
-			skb_frag_size_set(&rx_frags[i], MYRI10GE_ALLOC_SIZE);
+		skb_fill_page_desc(skb, i, rx->info[idx].page,
+				   rx->info[idx].page_offset,
+				   remainder < MYRI10GE_ALLOC_SIZE ?
+				   remainder : MYRI10GE_ALLOC_SIZE);
 		rx->cnt++;
 		idx = rx->cnt & rx->mask;
 		remainder -= MYRI10GE_ALLOC_SIZE;
 	}
 
-	if (lro_enabled) {
-		rx_frags[0].page_offset += MXGEFW_PAD;
-		skb_frag_size_sub(&rx_frags[0], MXGEFW_PAD);
-		len -= MXGEFW_PAD;
-		lro_receive_frags(&ss->rx_done.lro_mgr, rx_frags,
-				  /* opaque, will come back in get_frag_header */
-				  len, len,
-				  (void *)(__force unsigned long)csum, csum);
+	/* remove padding */
+	rx_frags[0].page_offset += MXGEFW_PAD;
+	rx_frags[0].size -= MXGEFW_PAD;
+	len -= MXGEFW_PAD;
 
-		return 1;
-	}
-
-	hlen = MYRI10GE_HLEN > len ? len : MYRI10GE_HLEN;
-
-	/* allocate an skb to attach the page(s) to. This is done
-	 * after trying LRO, so as to avoid skb allocation overheads */
-
-	skb = netdev_alloc_skb(dev, MYRI10GE_HLEN + 16);
-	if (unlikely(skb == NULL)) {
-		ss->stats.rx_dropped++;
-		do {
-			i--;
-			__skb_frag_unref(&rx_frags[i]);
-		} while (i != 0);
-		return 0;
-	}
-
-	/* Attach the pages to the skb, and trim off any padding */
-	myri10ge_rx_skb_build(skb, va, rx_frags, len, hlen);
-	if (skb_frag_size(&skb_shinfo(skb)->frags[0]) <= 0) {
-		skb_frag_unref(skb, 0);
-		skb_shinfo(skb)->nr_frags = 0;
-	} else {
-		skb->truesize += bytes * skb_shinfo(skb)->nr_frags;
+	skb->len = len;
+	skb->data_len = len;
+	skb->truesize += len;
+	if (dev->features & NETIF_F_RXCSUM) {
+		skb->ip_summed = CHECKSUM_COMPLETE;
+		skb->csum = csum;
 	}
-	skb->protocol = eth_type_trans(skb, dev);
 	skb_record_rx_queue(skb, ss - &mgp->ss[0]);
 
-	if (dev->features & NETIF_F_RXCSUM) {
-		if ((skb->protocol == htons(ETH_P_IP)) ||
-		    (skb->protocol == htons(ETH_P_IPV6))) {
-			skb->csum = csum;
-			skb->ip_summed = CHECKSUM_COMPLETE;
-		} else
-			myri10ge_vlan_ip_csum(skb, csum);
-	}
-	netif_receive_skb(skb);
+	napi_gro_frags(&ss->napi);
 	return 1;
 }
 
@@ -1480,18 +1416,11 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
 	u16 length;
 	__wsum checksum;
 
-	/*
-	 * Prevent compiler from generating more than one ->features memory
-	 * access to avoid theoretical race condition with functions that
-	 * change NETIF_F_LRO flag at runtime.
-	 */
-	bool lro_enabled = !!(ACCESS_ONCE(mgp->dev->features) & NETIF_F_LRO);
-
 	while (rx_done->entry[idx].length != 0 && work_done < budget) {
 		length = ntohs(rx_done->entry[idx].length);
 		rx_done->entry[idx].length = 0;
 		checksum = csum_unfold(rx_done->entry[idx].checksum);
-		rx_ok = myri10ge_rx_done(ss, length, checksum, lro_enabled);
+		rx_ok = myri10ge_rx_done(ss, length, checksum);
 		rx_packets += rx_ok;
 		rx_bytes += rx_ok * (unsigned long)length;
 		cnt++;
@@ -1503,9 +1432,6 @@ myri10ge_clean_rx_done(struct myri10ge_slice_state *ss, int budget)
 	ss->stats.rx_packets += rx_packets;
 	ss->stats.rx_bytes += rx_bytes;
 
-	if (lro_enabled)
-		lro_flush_all(&rx_done->lro_mgr);
-
 	/* restock receive rings if needed */
 	if (ss->rx_small.fill_cnt - ss->rx_small.cnt < myri10ge_fill_thresh)
 		myri10ge_alloc_rx_pages(mgp, &ss->rx_small,
@@ -1779,7 +1705,6 @@ static const char myri10ge_gstrings_slice_stats[][ETH_GSTRING_LEN] = {
 	"tx_pkt_start", "tx_pkt_done", "tx_req", "tx_done",
 	"rx_small_cnt", "rx_big_cnt",
 	"wake_queue", "stop_queue", "tx_linearized",
-	"LRO aggregated", "LRO flushed", "LRO avg aggr", "LRO no_desc",
 };
 
 #define MYRI10GE_NET_STATS_LEN      21
@@ -1880,14 +1805,6 @@ myri10ge_get_ethtool_stats(struct net_device *netdev,
 		data[i++] = (unsigned int)ss->tx.wake_queue;
 		data[i++] = (unsigned int)ss->tx.stop_queue;
 		data[i++] = (unsigned int)ss->tx.linearized;
-		data[i++] = ss->rx_done.lro_mgr.stats.aggregated;
-		data[i++] = ss->rx_done.lro_mgr.stats.flushed;
-		if (ss->rx_done.lro_mgr.stats.flushed)
-			data[i++] = ss->rx_done.lro_mgr.stats.aggregated /
-			    ss->rx_done.lro_mgr.stats.flushed;
-		else
-			data[i++] = 0;
-		data[i++] = ss->rx_done.lro_mgr.stats.no_desc;
 	}
 }
 
@@ -2271,67 +2188,6 @@ static void myri10ge_free_irq(struct myri10ge_priv *mgp)
 		pci_disable_msix(pdev);
 }
 
-static int
-myri10ge_get_frag_header(struct skb_frag_struct *frag, void **mac_hdr,
-			 void **ip_hdr, void **tcpudp_hdr,
-			 u64 * hdr_flags, void *priv)
-{
-	struct ethhdr *eh;
-	struct vlan_ethhdr *veh;
-	struct iphdr *iph;
-	u8 *va = skb_frag_address(frag);
-	unsigned long ll_hlen;
-	/* passed opaque through lro_receive_frags() */
-	__wsum csum = (__force __wsum) (unsigned long)priv;
-
-	/* find the mac header, aborting if not IPv4 */
-
-	eh = (struct ethhdr *)va;
-	*mac_hdr = eh;
-	ll_hlen = ETH_HLEN;
-	if (eh->h_proto != htons(ETH_P_IP)) {
-		if (eh->h_proto == htons(ETH_P_8021Q)) {
-			veh = (struct vlan_ethhdr *)va;
-			if (veh->h_vlan_encapsulated_proto != htons(ETH_P_IP))
-				return -1;
-
-			ll_hlen += VLAN_HLEN;
-
-			/*
-			 *  HW checksum starts ETH_HLEN bytes into
-			 *  frame, so we must subtract off the VLAN
-			 *  header's checksum before csum can be used
-			 */
-			csum = csum_sub(csum, csum_partial(va + ETH_HLEN,
-							   VLAN_HLEN, 0));
-		} else {
-			return -1;
-		}
-	}
-	*hdr_flags = LRO_IPV4;
-
-	iph = (struct iphdr *)(va + ll_hlen);
-	*ip_hdr = iph;
-	if (iph->protocol != IPPROTO_TCP)
-		return -1;
-	if (ip_is_fragment(iph))
-		return -1;
-	*hdr_flags |= LRO_TCP;
-	*tcpudp_hdr = (u8 *) (*ip_hdr) + (iph->ihl << 2);
-
-	/* verify the IP checksum */
-	if (unlikely(ip_fast_csum((u8 *) iph, iph->ihl)))
-		return -1;
-
-	/* verify the  checksum */
-	if (unlikely(csum_tcpudp_magic(iph->saddr, iph->daddr,
-				       ntohs(iph->tot_len) - (iph->ihl << 2),
-				       IPPROTO_TCP, csum)))
-		return -1;
-
-	return 0;
-}
-
 static int myri10ge_get_txrx(struct myri10ge_priv *mgp, int slice)
 {
 	struct myri10ge_cmd cmd;
@@ -2402,7 +2258,6 @@ static int myri10ge_open(struct net_device *dev)
 	struct myri10ge_cmd cmd;
 	int i, status, big_pow2, slice;
 	u8 *itable;
-	struct net_lro_mgr *lro_mgr;
 
 	if (mgp->running != MYRI10GE_ETH_STOPPED)
 		return -EBUSY;
@@ -2513,19 +2368,6 @@ static int myri10ge_open(struct net_device *dev)
 			goto abort_with_rings;
 		}
 
-		lro_mgr = &ss->rx_done.lro_mgr;
-		lro_mgr->dev = dev;
-		lro_mgr->features = LRO_F_NAPI;
-		lro_mgr->ip_summed = CHECKSUM_COMPLETE;
-		lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
-		lro_mgr->max_desc = MYRI10GE_MAX_LRO_DESCRIPTORS;
-		lro_mgr->lro_arr = ss->rx_done.lro_desc;
-		lro_mgr->get_frag_header = myri10ge_get_frag_header;
-		lro_mgr->max_aggr = myri10ge_lro_max_pkts;
-		lro_mgr->frag_align_pad = 2;
-		if (lro_mgr->max_aggr > MAX_SKB_FRAGS)
-			lro_mgr->max_aggr = MAX_SKB_FRAGS;
-
 		/* must happen prior to any irq */
 		napi_enable(&(ss)->napi);
 	}
@@ -3143,15 +2985,6 @@ static int myri10ge_set_mac_address(struct net_device *dev, void *addr)
 	return 0;
 }
 
-static netdev_features_t myri10ge_fix_features(struct net_device *dev,
-	netdev_features_t features)
-{
-	if (!(features & NETIF_F_RXCSUM))
-		features &= ~NETIF_F_LRO;
-
-	return features;
-}
-
 static int myri10ge_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct myri10ge_priv *mgp = netdev_priv(dev);
@@ -3878,7 +3711,6 @@ static const struct net_device_ops myri10ge_netdev_ops = {
 	.ndo_get_stats64	= myri10ge_get_stats,
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_change_mtu		= myri10ge_change_mtu,
-	.ndo_fix_features	= myri10ge_fix_features,
 	.ndo_set_rx_mode	= myri10ge_set_multicast_list,
 	.ndo_set_mac_address	= myri10ge_set_mac_address,
 };
@@ -4018,7 +3850,7 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	netdev->netdev_ops = &myri10ge_netdev_ops;
 	netdev->mtu = myri10ge_initial_mtu;
-	netdev->hw_features = mgp->features | NETIF_F_LRO | NETIF_F_RXCSUM;
+	netdev->hw_features = mgp->features | NETIF_F_RXCSUM;
 	netdev->features = netdev->hw_features;
 
 	if (dac_enabled)
-- 
1.7.9.5

[PATCH v3 resend net-next 2/2] myri10ge: Add vlan rx for better GRO perf.

[Andrew Gallatin]

Unlike LRO, GRO requires that vlan tags be removed before
aggregation can occur.  Since the myri10ge NIC does not support
hardware vlan tag offload, we must remove the tag in the driver
to achieve performance comparable to LRO for vlan tagged frames.

Thanks to Eric Duzamet for his help simplifying the original patch.

Signed-off-by: Andrew Gallatin <gallatin@myri.com>
---
 drivers/net/ethernet/myricom/myri10ge/myri10ge.c |   41 ++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 84207c0..2fc984a 100644
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -1264,6 +1264,42 @@ myri10ge_unmap_rx_page(struct pci_dev *pdev,
 	}
 }
 
+/*
+ * GRO does not support acceleration of tagged vlan frames, and
+ * this NIC does not support vlan tag offload, so we must pop
+ * the tag ourselves to be able to achieve GRO performance that
+ * is comparable to LRO.
+ */
+
+static inline void
+myri10ge_vlan_rx(struct net_device *dev, void *addr, struct sk_buff *skb)
+{
+	u8 *va;
+	struct vlan_ethhdr *veh;
+	struct skb_frag_struct *frag;
+	__wsum vsum;
+
+	va = addr;
+	va += MXGEFW_PAD;
+	veh = (struct vlan_ethhdr *)va;
+	if ((dev->features & NETIF_F_HW_VLAN_RX) == NETIF_F_HW_VLAN_RX &&
+	    veh->h_vlan_proto == ntohs(ETH_P_8021Q)) {
+		/* fixup csum if needed */
+		if (skb->ip_summed == CHECKSUM_COMPLETE) {
+			vsum = csum_partial(va + ETH_HLEN, VLAN_HLEN, 0);
+			skb->csum = csum_sub(skb->csum, vsum);
+		}
+		/* pop tag */
+		__vlan_hwaccel_put_tag(skb, ntohs(veh->h_vlan_TCI));
+		memmove(va + VLAN_HLEN, va, 2 * ETH_ALEN);
+		skb->len -= VLAN_HLEN;
+		skb->data_len -= VLAN_HLEN;
+		frag = skb_shinfo(skb)->frags;
+		frag->page_offset += VLAN_HLEN;
+		skb_frag_size_set(frag, skb_frag_size(frag) - VLAN_HLEN);
+	}
+}
+
 static inline int
 myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
 {
@@ -1326,6 +1362,7 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
 		skb->ip_summed = CHECKSUM_COMPLETE;
 		skb->csum = csum;
 	}
+	myri10ge_vlan_rx(mgp->dev, va, skb);
 	skb_record_rx_queue(skb, ss - &mgp->ss[0]);
 
 	napi_gro_frags(&ss->napi);
@@ -3851,6 +3888,10 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	netdev->netdev_ops = &myri10ge_netdev_ops;
 	netdev->mtu = myri10ge_initial_mtu;
 	netdev->hw_features = mgp->features | NETIF_F_RXCSUM;
+
+	/* fake NETIF_F_HW_VLAN_RX for good GRO performance */
+	netdev->hw_features |= NETIF_F_HW_VLAN_RX;
+
 	netdev->features = netdev->hw_features;
 
 	if (dac_enabled)
-- 
1.7.9.5

Re: [PATCH v3 resend net-next 0/2] myri10ge: LRO to GRO conversion

[David Miller]

From: Andrew Gallatin <gallatin@myri.com>
Date: Fri, 30 Nov 2012 13:31:57 -0500

> I'm resending this after fixing email client issues.

Applied, thanks.

Re: [PATCH v3 resend net-next 0/2] myri10ge: LRO to GRO conversion

[Andrew Gallatin]

On 11/30/12 13:44, David Miller wrote:
> From: Andrew Gallatin <gallatin@myri.com>
> Date: Fri, 30 Nov 2012 13:31:57 -0500
> 
>> I'm resending this after fixing email client issues.
> 
> Applied, thanks.
> 

Thank you.

I also want to apologize for making so many beginner mistakes,
and to thank you for your patience with me.  There has usually
been somebody more "plugged in" to the linux community that
has submitted patches for us in the past, so I'm just not used
to doing it yet.

Thanks again,

Drew