--- /dev/null
+From patchwork Wed Oct 12 14:30:30 2016
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v2] IB/ipoib: move back IB LL address into the hard header
+From: Paolo Abeni <pabeni@redhat.com>
+X-Patchwork-Id: 681344
+X-Patchwork-Delegate: davem@davemloft.net
+Message-Id: <60efcf739ce3d45a01a7127dbaf7fe366e5ddce4.1476264804.git.pabeni@redhat.com>
+To: linux-rdma@vger.kernel.org
+Cc: Doug Ledford <dledford@redhat.com>, Sean Hefty <sean.hefty@intel.com>,
+ Hal Rosenstock <hal.rosenstock@gmail.com>,
+ Jason Gunthorpe <jgunthorpe@obsidianresearch.com>, netdev@vger.kernel.org
+Date: Wed, 12 Oct 2016 16:30:30 +0200
+
+After the commit 9207f9d45b0a ("net: preserve IP control block
+during GSO segmentation"), the GSO CB and the IPoIB CB conflict.
+That destroy the IPoIB address information cached there,
+causing a severe performance regression, as better described here:
+
+http://marc.info/?l=linux-kernel&m=146787279825501&w=2
+
+This change moves the data cached by the IPoIB driver from the
+skb control lock into the IPoIB hard header, as done before
+the commit 936d7de3d736 ("IPoIB: Stop lying about hard_header_len
+and use skb->cb to stash LL addresses").
+In order to avoid GRO issue, on packet reception, the IPoIB driver
+stash into the skb a dummy pseudo header, so that the received
+packets have actually a hard header matching the declared length.
+To avoid changing the connected mode maximum mtu, the allocated
+head buffer size is increased by the pseudo header length.
+
+After this commit, IPoIB performances are back to pre-regression
+value.
+
+v1 -> v2: avoid changing the max mtu, increasing the head buf size
+
+Fixes: 9207f9d45b0a ("net: preserve IP control block during GSO segmentation")
+Signed-off-by: Paolo Abeni <pabeni@redhat.com>
+---
+ drivers/infiniband/ulp/ipoib/ipoib.h | 20 +++++++---
+ drivers/infiniband/ulp/ipoib/ipoib_cm.c | 15 +++----
+ drivers/infiniband/ulp/ipoib/ipoib_ib.c | 12 +++---
+ drivers/infiniband/ulp/ipoib/ipoib_main.c | 54 ++++++++++++++++----------
+ drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 6 ++-
+ 5 files changed, 64 insertions(+), 43 deletions(-)
+
+diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
+index 9dbfcc0..5ff64af 100644
+--- a/drivers/infiniband/ulp/ipoib/ipoib.h
++++ b/drivers/infiniband/ulp/ipoib/ipoib.h
+@@ -63,6 +63,8 @@ enum ipoib_flush_level {
+
+ enum {
+ IPOIB_ENCAP_LEN = 4,
++ IPOIB_PSEUDO_LEN = 20,
++ IPOIB_HARD_LEN = IPOIB_ENCAP_LEN + IPOIB_PSEUDO_LEN,
+
+ IPOIB_UD_HEAD_SIZE = IB_GRH_BYTES + IPOIB_ENCAP_LEN,
+ IPOIB_UD_RX_SG = 2, /* max buffer needed for 4K mtu */
+@@ -134,15 +136,21 @@ struct ipoib_header {
+ u16 reserved;
+ };
+
+-struct ipoib_cb {
+- struct qdisc_skb_cb qdisc_cb;
+- u8 hwaddr[INFINIBAND_ALEN];
++struct ipoib_pseudo_header {
++ u8 hwaddr[INFINIBAND_ALEN];
+ };
+
+-static inline struct ipoib_cb *ipoib_skb_cb(const struct sk_buff *skb)
++static inline void skb_add_pseudo_hdr(struct sk_buff *skb)
+ {
+- BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct ipoib_cb));
+- return (struct ipoib_cb *)skb->cb;
++ char *data = skb_push(skb, IPOIB_PSEUDO_LEN);
++
++ /*
++ * only the ipoib header is present now, make room for a dummy
++ * pseudo header and set skb field accordingly
++ */
++ memset(data, 0, IPOIB_PSEUDO_LEN);
++ skb_reset_mac_header(skb);
++ skb_pull(skb, IPOIB_HARD_LEN);
+ }
+
+ /* Used for all multicast joins (broadcast, IPv4 mcast and IPv6 mcast) */
+diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+index 4ad297d..339a1ee 100644
+--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
++++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+@@ -63,6 +63,8 @@ MODULE_PARM_DESC(cm_data_debug_level,
+ #define IPOIB_CM_RX_DELAY (3 * 256 * HZ)
+ #define IPOIB_CM_RX_UPDATE_MASK (0x3)
+
++#define IPOIB_CM_RX_RESERVE (ALIGN(IPOIB_HARD_LEN, 16) - IPOIB_ENCAP_LEN)
++
+ static struct ib_qp_attr ipoib_cm_err_attr = {
+ .qp_state = IB_QPS_ERR
+ };
+@@ -146,15 +148,15 @@ static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev,
+ struct sk_buff *skb;
+ int i;
+
+- skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
++ skb = dev_alloc_skb(ALIGN(IPOIB_CM_HEAD_SIZE + IPOIB_PSEUDO_LEN, 16));
+ if (unlikely(!skb))
+ return NULL;
+
+ /*
+- * IPoIB adds a 4 byte header. So we need 12 more bytes to align the
++ * IPoIB adds a IPOIB_ENCAP_LEN byte header, this will align the
+ * IP header to a multiple of 16.
+ */
+- skb_reserve(skb, 12);
++ skb_reserve(skb, IPOIB_CM_RX_RESERVE);
+
+ mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
+ DMA_FROM_DEVICE);
+@@ -624,9 +626,9 @@ void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
+ if (wc->byte_len < IPOIB_CM_COPYBREAK) {
+ int dlen = wc->byte_len;
+
+- small_skb = dev_alloc_skb(dlen + 12);
++ small_skb = dev_alloc_skb(dlen + IPOIB_CM_RX_RESERVE);
+ if (small_skb) {
+- skb_reserve(small_skb, 12);
++ skb_reserve(small_skb, IPOIB_CM_RX_RESERVE);
+ ib_dma_sync_single_for_cpu(priv->ca, rx_ring[wr_id].mapping[0],
+ dlen, DMA_FROM_DEVICE);
+ skb_copy_from_linear_data(skb, small_skb->data, dlen);
+@@ -663,8 +665,7 @@ void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
+
+ copied:
+ skb->protocol = ((struct ipoib_header *) skb->data)->proto;
+- skb_reset_mac_header(skb);
+- skb_pull(skb, IPOIB_ENCAP_LEN);
++ skb_add_pseudo_hdr(skb);
+
+ ++dev->stats.rx_packets;
+ dev->stats.rx_bytes += skb->len;
+diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+index be11d5d..830fecb 100644
+--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
++++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+@@ -128,16 +128,15 @@ static struct sk_buff *ipoib_alloc_rx_skb(struct net_device *dev, int id)
+
+ buf_size = IPOIB_UD_BUF_SIZE(priv->max_ib_mtu);
+
+- skb = dev_alloc_skb(buf_size + IPOIB_ENCAP_LEN);
++ skb = dev_alloc_skb(buf_size + IPOIB_HARD_LEN);
+ if (unlikely(!skb))
+ return NULL;
+
+ /*
+- * IB will leave a 40 byte gap for a GRH and IPoIB adds a 4 byte
+- * header. So we need 4 more bytes to get to 48 and align the
+- * IP header to a multiple of 16.
++ * the IP header will be at IPOIP_HARD_LEN + IB_GRH_BYTES, that is
++ * 64 bytes aligned
+ */
+- skb_reserve(skb, 4);
++ skb_reserve(skb, sizeof(struct ipoib_pseudo_header));
+
+ mapping = priv->rx_ring[id].mapping;
+ mapping[0] = ib_dma_map_single(priv->ca, skb->data, buf_size,
+@@ -253,8 +252,7 @@ static void ipoib_ib_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
+ skb_pull(skb, IB_GRH_BYTES);
+
+ skb->protocol = ((struct ipoib_header *) skb->data)->proto;
+- skb_reset_mac_header(skb);
+- skb_pull(skb, IPOIB_ENCAP_LEN);
++ skb_add_pseudo_hdr(skb);
+
+ ++dev->stats.rx_packets;
+ dev->stats.rx_bytes += skb->len;
+diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
+index cc1c1b0..823a528 100644
+--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
++++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
+@@ -925,9 +925,12 @@ static void neigh_add_path(struct sk_buff *skb, u8 *daddr,
+ ipoib_neigh_free(neigh);
+ goto err_drop;
+ }
+- if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE)
++ if (skb_queue_len(&neigh->queue) <
++ IPOIB_MAX_PATH_REC_QUEUE) {
++ /* put pseudoheader back on for next time */
++ skb_push(skb, IPOIB_PSEUDO_LEN);
+ __skb_queue_tail(&neigh->queue, skb);
+- else {
++ } else {
+ ipoib_warn(priv, "queue length limit %d. Packet drop.\n",
+ skb_queue_len(&neigh->queue));
+ goto err_drop;
+@@ -964,7 +967,7 @@ err_drop:
+ }
+
+ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
+- struct ipoib_cb *cb)
++ struct ipoib_pseudo_header *phdr)
+ {
+ struct ipoib_dev_priv *priv = netdev_priv(dev);
+ struct ipoib_path *path;
+@@ -972,16 +975,18 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+- path = __path_find(dev, cb->hwaddr + 4);
++ path = __path_find(dev, phdr->hwaddr + 4);
+ if (!path || !path->valid) {
+ int new_path = 0;
+
+ if (!path) {
+- path = path_rec_create(dev, cb->hwaddr + 4);
++ path = path_rec_create(dev, phdr->hwaddr + 4);
+ new_path = 1;
+ }
+ if (path) {
+ if (skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
++ /* put pseudoheader back on for next time */
++ skb_push(skb, IPOIB_PSEUDO_LEN);
+ __skb_queue_tail(&path->queue, skb);
+ } else {
+ ++dev->stats.tx_dropped;
+@@ -1009,10 +1014,12 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
+ be16_to_cpu(path->pathrec.dlid));
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+- ipoib_send(dev, skb, path->ah, IPOIB_QPN(cb->hwaddr));
++ ipoib_send(dev, skb, path->ah, IPOIB_QPN(phdr->hwaddr));
+ return;
+ } else if ((path->query || !path_rec_start(dev, path)) &&
+ skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
++ /* put pseudoheader back on for next time */
++ skb_push(skb, IPOIB_PSEUDO_LEN);
+ __skb_queue_tail(&path->queue, skb);
+ } else {
+ ++dev->stats.tx_dropped;
+@@ -1026,13 +1033,15 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
+ {
+ struct ipoib_dev_priv *priv = netdev_priv(dev);
+ struct ipoib_neigh *neigh;
+- struct ipoib_cb *cb = ipoib_skb_cb(skb);
++ struct ipoib_pseudo_header *phdr;
+ struct ipoib_header *header;
+ unsigned long flags;
+
++ phdr = (struct ipoib_pseudo_header *) skb->data;
++ skb_pull(skb, sizeof(*phdr));
+ header = (struct ipoib_header *) skb->data;
+
+- if (unlikely(cb->hwaddr[4] == 0xff)) {
++ if (unlikely(phdr->hwaddr[4] == 0xff)) {
+ /* multicast, arrange "if" according to probability */
+ if ((header->proto != htons(ETH_P_IP)) &&
+ (header->proto != htons(ETH_P_IPV6)) &&
+@@ -1045,13 +1054,13 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
+ return NETDEV_TX_OK;
+ }
+ /* Add in the P_Key for multicast*/
+- cb->hwaddr[8] = (priv->pkey >> 8) & 0xff;
+- cb->hwaddr[9] = priv->pkey & 0xff;
++ phdr->hwaddr[8] = (priv->pkey >> 8) & 0xff;
++ phdr->hwaddr[9] = priv->pkey & 0xff;
+
+- neigh = ipoib_neigh_get(dev, cb->hwaddr);
++ neigh = ipoib_neigh_get(dev, phdr->hwaddr);
+ if (likely(neigh))
+ goto send_using_neigh;
+- ipoib_mcast_send(dev, cb->hwaddr, skb);
++ ipoib_mcast_send(dev, phdr->hwaddr, skb);
+ return NETDEV_TX_OK;
+ }
+
+@@ -1060,16 +1069,16 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
+ case htons(ETH_P_IP):
+ case htons(ETH_P_IPV6):
+ case htons(ETH_P_TIPC):
+- neigh = ipoib_neigh_get(dev, cb->hwaddr);
++ neigh = ipoib_neigh_get(dev, phdr->hwaddr);
+ if (unlikely(!neigh)) {
+- neigh_add_path(skb, cb->hwaddr, dev);
++ neigh_add_path(skb, phdr->hwaddr, dev);
+ return NETDEV_TX_OK;
+ }
+ break;
+ case htons(ETH_P_ARP):
+ case htons(ETH_P_RARP):
+ /* for unicast ARP and RARP should always perform path find */
+- unicast_arp_send(skb, dev, cb);
++ unicast_arp_send(skb, dev, phdr);
+ return NETDEV_TX_OK;
+ default:
+ /* ethertype not supported by IPoIB */
+@@ -1086,11 +1095,13 @@ send_using_neigh:
+ goto unref;
+ }
+ } else if (neigh->ah) {
+- ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(cb->hwaddr));
++ ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(phdr->hwaddr));
+ goto unref;
+ }
+
+ if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
++ /* put pseudoheader back on for next time */
++ skb_push(skb, sizeof(*phdr));
+ spin_lock_irqsave(&priv->lock, flags);
+ __skb_queue_tail(&neigh->queue, skb);
+ spin_unlock_irqrestore(&priv->lock, flags);
+@@ -1122,8 +1133,8 @@ static int ipoib_hard_header(struct sk_buff *skb,
+ unsigned short type,
+ const void *daddr, const void *saddr, unsigned len)
+ {
++ struct ipoib_pseudo_header *phdr;
+ struct ipoib_header *header;
+- struct ipoib_cb *cb = ipoib_skb_cb(skb);
+
+ header = (struct ipoib_header *) skb_push(skb, sizeof *header);
+
+@@ -1132,12 +1143,13 @@ static int ipoib_hard_header(struct sk_buff *skb,
+
+ /*
+ * we don't rely on dst_entry structure, always stuff the
+- * destination address into skb->cb so we can figure out where
++ * destination address into skb hard header so we can figure out where
+ * to send the packet later.
+ */
+- memcpy(cb->hwaddr, daddr, INFINIBAND_ALEN);
++ phdr = (struct ipoib_pseudo_header *) skb_push(skb, sizeof(*phdr));
++ memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
+
+- return sizeof *header;
++ return IPOIB_HARD_LEN;
+ }
+
+ static void ipoib_set_mcast_list(struct net_device *dev)
+@@ -1759,7 +1771,7 @@ void ipoib_setup(struct net_device *dev)
+
+ dev->flags |= IFF_BROADCAST | IFF_MULTICAST;
+
+- dev->hard_header_len = IPOIB_ENCAP_LEN;
++ dev->hard_header_len = IPOIB_HARD_LEN;
+ dev->addr_len = INFINIBAND_ALEN;
+ dev->type = ARPHRD_INFINIBAND;
+ dev->tx_queue_len = ipoib_sendq_size * 2;
+diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+index d3394b6..1909dd2 100644
+--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
++++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+@@ -796,9 +796,11 @@ void ipoib_mcast_send(struct net_device *dev, u8 *daddr, struct sk_buff *skb)
+ __ipoib_mcast_add(dev, mcast);
+ list_add_tail(&mcast->list, &priv->multicast_list);
+ }
+- if (skb_queue_len(&mcast->pkt_queue) < IPOIB_MAX_MCAST_QUEUE)
++ if (skb_queue_len(&mcast->pkt_queue) < IPOIB_MAX_MCAST_QUEUE) {
++ /* put pseudoheader back on for next time */
++ skb_push(skb, sizeof(struct ipoib_pseudo_header));
+ skb_queue_tail(&mcast->pkt_queue, skb);
+- else {
++ } else {
+ ++dev->stats.tx_dropped;
+ dev_kfree_skb_any(skb);
+ }
projects / pve-kernel-jessie.git / commitdiff