[PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[Eric Dumazet]

As mentioned half a year ago, we better switch mlx4 driver to order-0
allocations and page recycling.

This reduces vulnerability surface thanks to better skb->truesize
tracking and provides better performance in most cases.
(33 Gbit for one TCP flow on my lab hosts)

I will provide for linux-4.13 a patch on top of this series,
trying to improve data locality as described in
https://www.spinics.net/lists/netdev/msg422258.html

v2 provides an ethtool -S new counter (rx_alloc_pages) and
code factorization, plus Tariq fix.

v3 includes various fixes based on Tariq tests and feedback
from Saeed and Tariq.

v4 rebased on net-next for inclusion in linux-4.12, as requested
by Tariq.

Worth noting this patch series deletes ~250 lines of code ;)

Eric Dumazet (13):
  mlx4: dma_dir is a mlx4_en_priv attribute
  mlx4: remove order field from mlx4_en_frag_info
  mlx4: get rid of frag_prefix_size
  mlx4: rx_headroom is a per port attribute
  mlx4: reduce rx ring page_cache size
  mlx4: removal of frag_sizes[]
  mlx4: use order-0 pages for RX
  mlx4: add page recycling in receive path
  mlx4: add rx_alloc_pages counter in ethtool -S
  mlx4: do not access rx_desc from mlx4_en_process_rx_cq()
  mlx4: factorize page_address() calls
  mlx4: make validate_loopback() more generic
  mlx4: remove duplicate code in mlx4_en_process_rx_cq()

 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c  |   2 +-
 drivers/net/ethernet/mellanox/mlx4/en_port.c     |   2 +
 drivers/net/ethernet/mellanox/mlx4/en_rx.c       | 607 +++++++----------------
 drivers/net/ethernet/mellanox/mlx4/en_selftest.c |   6 -
 drivers/net/ethernet/mellanox/mlx4/en_tx.c       |   4 +-
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h     |  30 +-
 drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h  |   2 +-
 7 files changed, 201 insertions(+), 452 deletions(-)

-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 01/13] mlx4: dma_dir is a mlx4_en_priv attribute

[Eric Dumazet]

No need to duplicate it for all queues and frags.

num_frags & log_rx_info become u8 to save space.
u8 accesses are a bit faster than u16 anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 16 ++++++++--------
 drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  2 +-
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  6 +++---
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 867292880c07a15124a0cf099d1fcda09926548e..6183128b2d3d0519b46d14152b15c95ebbf62db7 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -72,7 +72,7 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
 			return -ENOMEM;
 	}
 	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE << order,
-			   frag_info->dma_dir);
+			   priv->dma_dir);
 	if (unlikely(dma_mapping_error(priv->ddev, dma))) {
 		put_page(page);
 		return -ENOMEM;
@@ -128,7 +128,7 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 		if (page_alloc[i].page != ring_alloc[i].page) {
 			dma_unmap_page(priv->ddev, page_alloc[i].dma,
 				page_alloc[i].page_size,
-				priv->frag_info[i].dma_dir);
+				priv->dma_dir);
 			page = page_alloc[i].page;
 			/* Revert changes done by mlx4_alloc_pages */
 			page_ref_sub(page, page_alloc[i].page_size /
@@ -149,7 +149,7 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
 
 	if (next_frag_end > frags[i].page_size)
 		dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size,
-			       frag_info->dma_dir);
+			       priv->dma_dir);
 
 	if (frags[i].page)
 		put_page(frags[i].page);
@@ -181,7 +181,7 @@ static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
 		page_alloc = &ring->page_alloc[i];
 		dma_unmap_page(priv->ddev, page_alloc->dma,
 			       page_alloc->page_size,
-			       priv->frag_info[i].dma_dir);
+			       priv->dma_dir);
 		page = page_alloc->page;
 		/* Revert changes done by mlx4_alloc_pages */
 		page_ref_sub(page, page_alloc->page_size /
@@ -206,7 +206,7 @@ static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
 		       i, page_count(page_alloc->page));
 
 		dma_unmap_page(priv->ddev, page_alloc->dma,
-				page_alloc->page_size, frag_info->dma_dir);
+				page_alloc->page_size, priv->dma_dir);
 		while (page_alloc->page_offset + frag_info->frag_stride <
 		       page_alloc->page_size) {
 			put_page(page_alloc->page);
@@ -570,7 +570,7 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
 		struct mlx4_en_rx_alloc *frame = &ring->page_cache.buf[i];
 
 		dma_unmap_page(priv->ddev, frame->dma, frame->page_size,
-			       priv->frag_info[0].dma_dir);
+			       priv->dma_dir);
 		put_page(frame->page);
 	}
 	ring->page_cache.index = 0;
@@ -1202,7 +1202,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		 * expense of more costly truesize accounting
 		 */
 		priv->frag_info[0].frag_stride = PAGE_SIZE;
-		priv->frag_info[0].dma_dir = PCI_DMA_BIDIRECTIONAL;
+		priv->dma_dir = PCI_DMA_BIDIRECTIONAL;
 		priv->frag_info[0].rx_headroom = XDP_PACKET_HEADROOM;
 		i = 1;
 	} else {
@@ -1217,11 +1217,11 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 			priv->frag_info[i].frag_stride =
 				ALIGN(priv->frag_info[i].frag_size,
 				      SMP_CACHE_BYTES);
-			priv->frag_info[i].dma_dir = PCI_DMA_FROMDEVICE;
 			priv->frag_info[i].rx_headroom = 0;
 			buf_size += priv->frag_info[i].frag_size;
 			i++;
 		}
+		priv->dma_dir = PCI_DMA_FROMDEVICE;
 	}
 
 	priv->num_frags = i;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 3ed42199d3f1275f77560e92a430c0dde181e95a..98bc67a7249b14f8857fe1fd6baa40ae3ec5a880 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -360,7 +360,7 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
 
 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
-			       PAGE_SIZE, priv->frag_info[0].dma_dir);
+			       PAGE_SIZE, priv->dma_dir);
 		put_page(tx_info->page);
 	}
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 3629ce11a68b9dec5c1659539bdc6f2c11114e35..a4c7d94d52c698c23c9768a4c0387378898cdbc5 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -474,7 +474,6 @@ struct mlx4_en_frag_info {
 	u16 frag_size;
 	u16 frag_prefix_size;
 	u32 frag_stride;
-	enum dma_data_direction dma_dir;
 	u16 order;
 	u16 rx_headroom;
 };
@@ -584,8 +583,9 @@ struct mlx4_en_priv {
 	u32 rx_ring_num;
 	u32 rx_skb_size;
 	struct mlx4_en_frag_info frag_info[MLX4_EN_MAX_RX_FRAGS];
-	u16 num_frags;
-	u16 log_rx_info;
+	u8 num_frags;
+	u8 log_rx_info;
+	u8 dma_dir;
 
 	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_rx_ring *rx_ring[MAX_RX_RINGS];
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 02/13] mlx4: remove order field from mlx4_en_frag_info

[Eric Dumazet]

This is really a port attribute, no need to duplicate it per
RX queue and per frag.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 6 +++---
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 6183128b2d3d0519b46d14152b15c95ebbf62db7..b78d6762e03fc9f0c9e8bfa710efc2e7c86ad306 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -59,7 +59,7 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
 	struct page *page;
 	dma_addr_t dma;
 
-	for (order = frag_info->order; ;) {
+	for (order = priv->rx_page_order; ;) {
 		gfp_t gfp = _gfp;
 
 		if (order)
@@ -1195,7 +1195,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	 * This only works when num_frags == 1.
 	 */
 	if (priv->tx_ring_num[TX_XDP]) {
-		priv->frag_info[0].order = 0;
+		priv->rx_page_order = 0;
 		priv->frag_info[0].frag_size = eff_mtu;
 		priv->frag_info[0].frag_prefix_size = 0;
 		/* This will gain efficient xdp frame recycling at the
@@ -1209,7 +1209,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		int buf_size = 0;
 
 		while (buf_size < eff_mtu) {
-			priv->frag_info[i].order = MLX4_EN_ALLOC_PREFER_ORDER;
 			priv->frag_info[i].frag_size =
 				(eff_mtu > buf_size + frag_sizes[i]) ?
 					frag_sizes[i] : eff_mtu - buf_size;
@@ -1221,6 +1220,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 			buf_size += priv->frag_info[i].frag_size;
 			i++;
 		}
+		priv->rx_page_order = MLX4_EN_ALLOC_PREFER_ORDER;
 		priv->dma_dir = PCI_DMA_FROMDEVICE;
 	}
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index a4c7d94d52c698c23c9768a4c0387378898cdbc5..9d2c53ddb15c6d2262272a1b429f0ebde366e3ac 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -474,7 +474,6 @@ struct mlx4_en_frag_info {
 	u16 frag_size;
 	u16 frag_prefix_size;
 	u32 frag_stride;
-	u16 order;
 	u16 rx_headroom;
 };
 
@@ -586,6 +585,7 @@ struct mlx4_en_priv {
 	u8 num_frags;
 	u8 log_rx_info;
 	u8 dma_dir;
+	u8 rx_page_order;
 
 	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_rx_ring *rx_ring[MAX_RX_RINGS];
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 03/13] mlx4: get rid of frag_prefix_size

[Eric Dumazet]

Using per frag storage for frag_prefix_size is really silly.

mlx4_en_complete_rx_desc() has all needed info already.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 27 ++++++++++++---------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  3 +--
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index b78d6762e03fc9f0c9e8bfa710efc2e7c86ad306..118ea83cff089f614a11f99f6623358f200638a8 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -588,15 +588,14 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
 				    int length)
 {
 	struct skb_frag_struct *skb_frags_rx = skb_shinfo(skb)->frags;
-	struct mlx4_en_frag_info *frag_info;
-	int nr;
+	struct mlx4_en_frag_info *frag_info = priv->frag_info;
+	int nr, frag_size;
 	dma_addr_t dma;
 
 	/* Collect used fragments while replacing them in the HW descriptors */
-	for (nr = 0; nr < priv->num_frags; nr++) {
-		frag_info = &priv->frag_info[nr];
-		if (length <= frag_info->frag_prefix_size)
-			break;
+	for (nr = 0;;) {
+		frag_size = min_t(int, length, frag_info->frag_size);
+
 		if (unlikely(!frags[nr].page))
 			goto fail;
 
@@ -606,15 +605,16 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
 
 		__skb_fill_page_desc(skb, nr, frags[nr].page,
 				     frags[nr].page_offset,
-				     frag_info->frag_size);
+				     frag_size);
 
 		skb->truesize += frag_info->frag_stride;
 		frags[nr].page = NULL;
+		nr++;
+		length -= frag_size;
+		if (!length)
+			break;
+		frag_info++;
 	}
-	/* Adjust size of last fragment to match actual length */
-	if (nr > 0)
-		skb_frag_size_set(&skb_frags_rx[nr - 1],
-			length - priv->frag_info[nr - 1].frag_prefix_size);
 	return nr;
 
 fail:
@@ -1197,7 +1197,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	if (priv->tx_ring_num[TX_XDP]) {
 		priv->rx_page_order = 0;
 		priv->frag_info[0].frag_size = eff_mtu;
-		priv->frag_info[0].frag_prefix_size = 0;
 		/* This will gain efficient xdp frame recycling at the
 		 * expense of more costly truesize accounting
 		 */
@@ -1212,7 +1211,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 			priv->frag_info[i].frag_size =
 				(eff_mtu > buf_size + frag_sizes[i]) ?
 					frag_sizes[i] : eff_mtu - buf_size;
-			priv->frag_info[i].frag_prefix_size = buf_size;
 			priv->frag_info[i].frag_stride =
 				ALIGN(priv->frag_info[i].frag_size,
 				      SMP_CACHE_BYTES);
@@ -1232,10 +1230,9 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	       eff_mtu, priv->num_frags);
 	for (i = 0; i < priv->num_frags; i++) {
 		en_err(priv,
-		       "  frag:%d - size:%d prefix:%d stride:%d\n",
+		       "  frag:%d - size:%d stride:%d\n",
 		       i,
 		       priv->frag_info[i].frag_size,
-		       priv->frag_info[i].frag_prefix_size,
 		       priv->frag_info[i].frag_stride);
 	}
 }
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 9d2c53ddb15c6d2262272a1b429f0ebde366e3ac..849aa8af4dd771cdd44fae25516980bd36ed45a8 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -472,9 +472,8 @@ struct mlx4_en_mc_list {
 
 struct mlx4_en_frag_info {
 	u16 frag_size;
-	u16 frag_prefix_size;
-	u32 frag_stride;
 	u16 rx_headroom;
+	u32 frag_stride;
 };
 
 #ifdef CONFIG_MLX4_EN_DCB
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 04/13] mlx4: rx_headroom is a per port attribute

[Eric Dumazet]

No need to duplicate it per RX queue / frags.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 6 +++---
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 118ea83cff089f614a11f99f6623358f200638a8..bb33032a280f00ee62cc39d4261e72543ed0434e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -115,7 +115,7 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 
 	for (i = 0; i < priv->num_frags; i++) {
 		frags[i] = ring_alloc[i];
-		frags[i].page_offset += priv->frag_info[i].rx_headroom;
+		frags[i].page_offset += priv->rx_headroom;
 		rx_desc->data[i].addr = cpu_to_be64(frags[i].dma +
 						    frags[i].page_offset);
 		ring_alloc[i] = page_alloc[i];
@@ -1202,7 +1202,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		 */
 		priv->frag_info[0].frag_stride = PAGE_SIZE;
 		priv->dma_dir = PCI_DMA_BIDIRECTIONAL;
-		priv->frag_info[0].rx_headroom = XDP_PACKET_HEADROOM;
+		priv->rx_headroom = XDP_PACKET_HEADROOM;
 		i = 1;
 	} else {
 		int buf_size = 0;
@@ -1214,12 +1214,12 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 			priv->frag_info[i].frag_stride =
 				ALIGN(priv->frag_info[i].frag_size,
 				      SMP_CACHE_BYTES);
-			priv->frag_info[i].rx_headroom = 0;
 			buf_size += priv->frag_info[i].frag_size;
 			i++;
 		}
 		priv->rx_page_order = MLX4_EN_ALLOC_PREFER_ORDER;
 		priv->dma_dir = PCI_DMA_FROMDEVICE;
+		priv->rx_headroom = 0;
 	}
 
 	priv->num_frags = i;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 849aa8af4dd771cdd44fae25516980bd36ed45a8..fc7b4da5d8c376455c642d9512a8565d88db42a3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -472,7 +472,6 @@ struct mlx4_en_mc_list {
 
 struct mlx4_en_frag_info {
 	u16 frag_size;
-	u16 rx_headroom;
 	u32 frag_stride;
 };
 
@@ -585,6 +584,7 @@ struct mlx4_en_priv {
 	u8 log_rx_info;
 	u8 dma_dir;
 	u8 rx_page_order;
+	u16 rx_headroom;
 
 	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_rx_ring *rx_ring[MAX_RX_RINGS];
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 05/13] mlx4: reduce rx ring page_cache size

[Eric Dumazet]

We only need to store the page and dma address.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 17 ++++++++++-------
 drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  2 --
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  6 +++++-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index bb33032a280f00ee62cc39d4261e72543ed0434e..453313d404e3698b0d41a8220005b3834c9d68a1 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -250,7 +250,10 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 					(index << priv->log_rx_info);
 
 	if (ring->page_cache.index > 0) {
-		frags[0] = ring->page_cache.buf[--ring->page_cache.index];
+		ring->page_cache.index--;
+		frags[0].page = ring->page_cache.buf[ring->page_cache.index].page;
+		frags[0].dma  = ring->page_cache.buf[ring->page_cache.index].dma;
+		frags[0].page_offset = XDP_PACKET_HEADROOM;
 		rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
 						    frags[0].page_offset);
 		return 0;
@@ -537,7 +540,9 @@ bool mlx4_en_rx_recycle(struct mlx4_en_rx_ring *ring,
 	if (cache->index >= MLX4_EN_CACHE_SIZE)
 		return false;
 
-	cache->buf[cache->index++] = *frame;
+	cache->buf[cache->index].page = frame->page;
+	cache->buf[cache->index].dma = frame->dma;
+	cache->index++;
 	return true;
 }
 
@@ -567,11 +572,9 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
 	int i;
 
 	for (i = 0; i < ring->page_cache.index; i++) {
-		struct mlx4_en_rx_alloc *frame = &ring->page_cache.buf[i];
-
-		dma_unmap_page(priv->ddev, frame->dma, frame->page_size,
-			       priv->dma_dir);
-		put_page(frame->page);
+		dma_unmap_page(priv->ddev, ring->page_cache.buf[i].dma,
+			       PAGE_SIZE, priv->dma_dir);
+		put_page(ring->page_cache.buf[i].page);
 	}
 	ring->page_cache.index = 0;
 	mlx4_en_free_rx_buf(priv, ring);
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 98bc67a7249b14f8857fe1fd6baa40ae3ec5a880..e0c5ffb3e3a6607456e1f191b0b8c8becfc71219 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -354,8 +354,6 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
 	struct mlx4_en_rx_alloc frame = {
 		.page = tx_info->page,
 		.dma = tx_info->map0_dma,
-		.page_offset = XDP_PACKET_HEADROOM,
-		.page_size = PAGE_SIZE,
 	};
 
 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index fc7b4da5d8c376455c642d9512a8565d88db42a3..c98940c6acd02c1bd8c4f82107d82979ead051d1 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -268,9 +268,13 @@ struct mlx4_en_rx_alloc {
 };
 
 #define MLX4_EN_CACHE_SIZE (2 * NAPI_POLL_WEIGHT)
+
 struct mlx4_en_page_cache {
 	u32 index;
-	struct mlx4_en_rx_alloc buf[MLX4_EN_CACHE_SIZE];
+	struct {
+		struct page	*page;
+		dma_addr_t	dma;
+	} buf[MLX4_EN_CACHE_SIZE];
 };
 
 struct mlx4_en_priv;
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 06/13] mlx4: removal of frag_sizes[]

[Eric Dumazet]

We will soon use order-0 pages, and frag truesize will more precisely
match real sizes.

In the new model, we prefer to use <= 2048 bytes fragments, so that
we can use page-recycle technique on PAGE_SIZE=4096 arches.

We will still pack as much frames as possible on arches with big
pages, like PowerPC.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 24 ++++++++++--------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  8 --------
 2 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 453313d404e3698b0d41a8220005b3834c9d68a1..0c61c1200f2aec4c74d7403d9ec3ed06821c1bac 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -1181,13 +1181,6 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
 	return done;
 }
 
-static const int frag_sizes[] = {
-	FRAG_SZ0,
-	FRAG_SZ1,
-	FRAG_SZ2,
-	FRAG_SZ3
-};
-
 void mlx4_en_calc_rx_buf(struct net_device *dev)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
@@ -1211,13 +1204,16 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		int buf_size = 0;
 
 		while (buf_size < eff_mtu) {
-			priv->frag_info[i].frag_size =
-				(eff_mtu > buf_size + frag_sizes[i]) ?
-					frag_sizes[i] : eff_mtu - buf_size;
-			priv->frag_info[i].frag_stride =
-				ALIGN(priv->frag_info[i].frag_size,
-				      SMP_CACHE_BYTES);
-			buf_size += priv->frag_info[i].frag_size;
+			int frag_size = eff_mtu - buf_size;
+
+			if (i < MLX4_EN_MAX_RX_FRAGS - 1)
+				frag_size = min(frag_size, 2048);
+
+			priv->frag_info[i].frag_size = frag_size;
+
+			priv->frag_info[i].frag_stride = ALIGN(frag_size,
+							       SMP_CACHE_BYTES);
+			buf_size += frag_size;
 			i++;
 		}
 		priv->rx_page_order = MLX4_EN_ALLOC_PREFER_ORDER;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index c98940c6acd02c1bd8c4f82107d82979ead051d1..608396dc6d95a05cd88bcf054df990298365ecfa 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -105,14 +105,6 @@
 #define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768),		\
 					 PAGE_ALLOC_COSTLY_ORDER)
 
-/* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU
- * and 4K allocations) */
-enum {
-	FRAG_SZ0 = 1536 - NET_IP_ALIGN,
-	FRAG_SZ1 = 4096,
-	FRAG_SZ2 = 4096,
-	FRAG_SZ3 = MLX4_EN_ALLOC_SIZE
-};
 #define MLX4_EN_MAX_RX_FRAGS	4
 
 /* Maximum ring sizes */
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 07/13] mlx4: use order-0 pages for RX

[Eric Dumazet]

Use of order-3 pages is problematic in some cases.

This patch might add three kinds of regression :

1) a CPU performance regression, but we will add later page
recycling and performance should be back.

2) TCP receiver could grow its receive window slightly slower,
   because skb->len/skb->truesize ratio will decrease.
   This is mostly ok, we prefer being conservative to not risk OOM,
   and eventually tune TCP better in the future.
   This is consistent with other drivers using 2048 per ethernet frame.

3) Because we allocate one page per RX slot, we consume more
   memory for the ring buffers. XDP already had this constraint anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 72 +++++++++++++---------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  5 --
 2 files changed, 33 insertions(+), 44 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 0c61c1200f2aec4c74d7403d9ec3ed06821c1bac..069ea09185fb0669d5c1f9b1b88f517b2d69c5ed 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -53,38 +53,26 @@
 static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
 			    struct mlx4_en_rx_alloc *page_alloc,
 			    const struct mlx4_en_frag_info *frag_info,
-			    gfp_t _gfp)
+			    gfp_t gfp)
 {
-	int order;
 	struct page *page;
 	dma_addr_t dma;
 
-	for (order = priv->rx_page_order; ;) {
-		gfp_t gfp = _gfp;
-
-		if (order)
-			gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NOMEMALLOC;
-		page = alloc_pages(gfp, order);
-		if (likely(page))
-			break;
-		if (--order < 0 ||
-		    ((PAGE_SIZE << order) < frag_info->frag_size))
-			return -ENOMEM;
-	}
-	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE << order,
-			   priv->dma_dir);
+	page = alloc_page(gfp);
+	if (unlikely(!page))
+		return -ENOMEM;
+	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE, priv->dma_dir);
 	if (unlikely(dma_mapping_error(priv->ddev, dma))) {
 		put_page(page);
 		return -ENOMEM;
 	}
-	page_alloc->page_size = PAGE_SIZE << order;
 	page_alloc->page = page;
 	page_alloc->dma = dma;
 	page_alloc->page_offset = 0;
 	/* Not doing get_page() for each frag is a big win
 	 * on asymetric workloads. Note we can not use atomic_set().
 	 */
-	page_ref_add(page, page_alloc->page_size / frag_info->frag_stride - 1);
+	page_ref_add(page, PAGE_SIZE / frag_info->frag_stride - 1);
 	return 0;
 }
 
@@ -105,7 +93,7 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 		page_alloc[i].page_offset += frag_info->frag_stride;
 
 		if (page_alloc[i].page_offset + frag_info->frag_stride <=
-		    ring_alloc[i].page_size)
+		    PAGE_SIZE)
 			continue;
 
 		if (unlikely(mlx4_alloc_pages(priv, &page_alloc[i],
@@ -127,11 +115,10 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 	while (i--) {
 		if (page_alloc[i].page != ring_alloc[i].page) {
 			dma_unmap_page(priv->ddev, page_alloc[i].dma,
-				page_alloc[i].page_size,
-				priv->dma_dir);
+				       PAGE_SIZE, priv->dma_dir);
 			page = page_alloc[i].page;
 			/* Revert changes done by mlx4_alloc_pages */
-			page_ref_sub(page, page_alloc[i].page_size /
+			page_ref_sub(page, PAGE_SIZE /
 					   priv->frag_info[i].frag_stride - 1);
 			put_page(page);
 		}
@@ -147,8 +134,8 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
 	u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;
 
 
-	if (next_frag_end > frags[i].page_size)
-		dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size,
+	if (next_frag_end > PAGE_SIZE)
+		dma_unmap_page(priv->ddev, frags[i].dma, PAGE_SIZE,
 			       priv->dma_dir);
 
 	if (frags[i].page)
@@ -168,9 +155,8 @@ static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
 				     frag_info, GFP_KERNEL | __GFP_COLD))
 			goto out;
 
-		en_dbg(DRV, priv, "  frag %d allocator: - size:%d frags:%d\n",
-		       i, ring->page_alloc[i].page_size,
-		       page_ref_count(ring->page_alloc[i].page));
+		en_dbg(DRV, priv, "  frag %d allocator: - frags:%d\n",
+		       i, page_ref_count(ring->page_alloc[i].page));
 	}
 	return 0;
 
@@ -180,11 +166,10 @@ static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
 
 		page_alloc = &ring->page_alloc[i];
 		dma_unmap_page(priv->ddev, page_alloc->dma,
-			       page_alloc->page_size,
-			       priv->dma_dir);
+			       PAGE_SIZE, priv->dma_dir);
 		page = page_alloc->page;
 		/* Revert changes done by mlx4_alloc_pages */
-		page_ref_sub(page, page_alloc->page_size /
+		page_ref_sub(page, PAGE_SIZE /
 				   priv->frag_info[i].frag_stride - 1);
 		put_page(page);
 		page_alloc->page = NULL;
@@ -206,9 +191,9 @@ static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
 		       i, page_count(page_alloc->page));
 
 		dma_unmap_page(priv->ddev, page_alloc->dma,
-				page_alloc->page_size, priv->dma_dir);
+			       PAGE_SIZE, priv->dma_dir);
 		while (page_alloc->page_offset + frag_info->frag_stride <
-		       page_alloc->page_size) {
+		       PAGE_SIZE) {
 			put_page(page_alloc->page);
 			page_alloc->page_offset += frag_info->frag_stride;
 		}
@@ -1191,7 +1176,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 	 * This only works when num_frags == 1.
 	 */
 	if (priv->tx_ring_num[TX_XDP]) {
-		priv->rx_page_order = 0;
 		priv->frag_info[0].frag_size = eff_mtu;
 		/* This will gain efficient xdp frame recycling at the
 		 * expense of more costly truesize accounting
@@ -1201,22 +1185,32 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
 		priv->rx_headroom = XDP_PACKET_HEADROOM;
 		i = 1;
 	} else {
-		int buf_size = 0;
+		int frag_size_max = 2048, buf_size = 0;
+
+		/* should not happen, right ? */
+		if (eff_mtu > PAGE_SIZE + (MLX4_EN_MAX_RX_FRAGS - 1) * 2048)
+			frag_size_max = PAGE_SIZE;
 
 		while (buf_size < eff_mtu) {
-			int frag_size = eff_mtu - buf_size;
+			int frag_stride, frag_size = eff_mtu - buf_size;
+			int pad, nb;
 
 			if (i < MLX4_EN_MAX_RX_FRAGS - 1)
-				frag_size = min(frag_size, 2048);
+				frag_size = min(frag_size, frag_size_max);
 
 			priv->frag_info[i].frag_size = frag_size;
+			frag_stride = ALIGN(frag_size, SMP_CACHE_BYTES);
+			/* We can only pack 2 1536-bytes frames in on 4K page
+			 * Therefore, each frame would consume more bytes (truesize)
+			 */
+			nb = PAGE_SIZE / frag_stride;
+			pad = (PAGE_SIZE - nb * frag_stride) / nb;
+			pad &= ~(SMP_CACHE_BYTES - 1);
+			priv->frag_info[i].frag_stride = frag_stride + pad;
 
-			priv->frag_info[i].frag_stride = ALIGN(frag_size,
-							       SMP_CACHE_BYTES);
 			buf_size += frag_size;
 			i++;
 		}
-		priv->rx_page_order = MLX4_EN_ALLOC_PREFER_ORDER;
 		priv->dma_dir = PCI_DMA_FROMDEVICE;
 		priv->rx_headroom = 0;
 	}
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 608396dc6d95a05cd88bcf054df990298365ecfa..6c80117006edf25de46fe60fd36051ee9b10d3cb 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -102,9 +102,6 @@
 /* Use the maximum between 16384 and a single page */
 #define MLX4_EN_ALLOC_SIZE	PAGE_ALIGN(16384)
 
-#define MLX4_EN_ALLOC_PREFER_ORDER min_t(int, get_order(32768),		\
-					 PAGE_ALLOC_COSTLY_ORDER)
-
 #define MLX4_EN_MAX_RX_FRAGS	4
 
 /* Maximum ring sizes */
@@ -256,7 +253,6 @@ struct mlx4_en_rx_alloc {
 	struct page	*page;
 	dma_addr_t	dma;
 	u32		page_offset;
-	u32		page_size;
 };
 
 #define MLX4_EN_CACHE_SIZE (2 * NAPI_POLL_WEIGHT)
@@ -579,7 +575,6 @@ struct mlx4_en_priv {
 	u8 num_frags;
 	u8 log_rx_info;
 	u8 dma_dir;
-	u8 rx_page_order;
 	u16 rx_headroom;
 
 	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 08/13] mlx4: add page recycling in receive path

[Eric Dumazet]

Same technique than some Intel drivers, for arches where PAGE_SIZE = 4096

In most cases, pages are reused because they were consumed
before we could loop around the RX ring.

This brings back performance, and is even better,
a single TCP flow reaches 30Gbit on my hosts.

v2: added full memset() in mlx4_en_free_frag(), as Tariq found it was needed
if we switch to large MTU, as priv->log_rx_info can dynamically be changed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 258 +++++++++------------------
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |   1 -
 2 files changed, 82 insertions(+), 177 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 069ea09185fb0669d5c1f9b1b88f517b2d69c5ed..5edd0cf2999cbde37b3404aafd700584696af940 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -50,10 +50,9 @@
 
 #include "mlx4_en.h"
 
-static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
-			    struct mlx4_en_rx_alloc *page_alloc,
-			    const struct mlx4_en_frag_info *frag_info,
-			    gfp_t gfp)
+static int mlx4_alloc_page(struct mlx4_en_priv *priv,
+			   struct mlx4_en_rx_alloc *frag,
+			   gfp_t gfp)
 {
 	struct page *page;
 	dma_addr_t dma;
@@ -63,145 +62,46 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
 		return -ENOMEM;
 	dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE, priv->dma_dir);
 	if (unlikely(dma_mapping_error(priv->ddev, dma))) {
-		put_page(page);
+		__free_page(page);
 		return -ENOMEM;
 	}
-	page_alloc->page = page;
-	page_alloc->dma = dma;
-	page_alloc->page_offset = 0;
-	/* Not doing get_page() for each frag is a big win
-	 * on asymetric workloads. Note we can not use atomic_set().
-	 */
-	page_ref_add(page, PAGE_SIZE / frag_info->frag_stride - 1);
+	frag->page = page;
+	frag->dma = dma;
+	frag->page_offset = priv->rx_headroom;
 	return 0;
 }
 
 static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 			       struct mlx4_en_rx_desc *rx_desc,
 			       struct mlx4_en_rx_alloc *frags,
-			       struct mlx4_en_rx_alloc *ring_alloc,
 			       gfp_t gfp)
 {
-	struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
-	const struct mlx4_en_frag_info *frag_info;
-	struct page *page;
 	int i;
 
-	for (i = 0; i < priv->num_frags; i++) {
-		frag_info = &priv->frag_info[i];
-		page_alloc[i] = ring_alloc[i];
-		page_alloc[i].page_offset += frag_info->frag_stride;
-
-		if (page_alloc[i].page_offset + frag_info->frag_stride <=
-		    PAGE_SIZE)
-			continue;
-
-		if (unlikely(mlx4_alloc_pages(priv, &page_alloc[i],
-					      frag_info, gfp)))
-			goto out;
-	}
-
-	for (i = 0; i < priv->num_frags; i++) {
-		frags[i] = ring_alloc[i];
-		frags[i].page_offset += priv->rx_headroom;
-		rx_desc->data[i].addr = cpu_to_be64(frags[i].dma +
-						    frags[i].page_offset);
-		ring_alloc[i] = page_alloc[i];
-	}
-
-	return 0;
-
-out:
-	while (i--) {
-		if (page_alloc[i].page != ring_alloc[i].page) {
-			dma_unmap_page(priv->ddev, page_alloc[i].dma,
-				       PAGE_SIZE, priv->dma_dir);
-			page = page_alloc[i].page;
-			/* Revert changes done by mlx4_alloc_pages */
-			page_ref_sub(page, PAGE_SIZE /
-					   priv->frag_info[i].frag_stride - 1);
-			put_page(page);
-		}
-	}
-	return -ENOMEM;
-}
-
-static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
-			      struct mlx4_en_rx_alloc *frags,
-			      int i)
-{
-	const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-	u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;
-
-
-	if (next_frag_end > PAGE_SIZE)
-		dma_unmap_page(priv->ddev, frags[i].dma, PAGE_SIZE,
-			       priv->dma_dir);
-
-	if (frags[i].page)
-		put_page(frags[i].page);
-}
-
-static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
-				  struct mlx4_en_rx_ring *ring)
-{
-	int i;
-	struct mlx4_en_rx_alloc *page_alloc;
-
-	for (i = 0; i < priv->num_frags; i++) {
-		const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-
-		if (mlx4_alloc_pages(priv, &ring->page_alloc[i],
-				     frag_info, GFP_KERNEL | __GFP_COLD))
-			goto out;
-
-		en_dbg(DRV, priv, "  frag %d allocator: - frags:%d\n",
-		       i, page_ref_count(ring->page_alloc[i].page));
+	for (i = 0; i < priv->num_frags; i++, frags++) {
+		if (!frags->page && mlx4_alloc_page(priv, frags, gfp))
+			return -ENOMEM;
+		rx_desc->data[i].addr = cpu_to_be64(frags->dma +
+						    frags->page_offset);
 	}
 	return 0;
-
-out:
-	while (i--) {
-		struct page *page;
-
-		page_alloc = &ring->page_alloc[i];
-		dma_unmap_page(priv->ddev, page_alloc->dma,
-			       PAGE_SIZE, priv->dma_dir);
-		page = page_alloc->page;
-		/* Revert changes done by mlx4_alloc_pages */
-		page_ref_sub(page, PAGE_SIZE /
-				   priv->frag_info[i].frag_stride - 1);
-		put_page(page);
-		page_alloc->page = NULL;
-	}
-	return -ENOMEM;
 }
 
-static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
-				      struct mlx4_en_rx_ring *ring)
+static void mlx4_en_free_frag(const struct mlx4_en_priv *priv,
+			      struct mlx4_en_rx_alloc *frag)
 {
-	struct mlx4_en_rx_alloc *page_alloc;
-	int i;
-
-	for (i = 0; i < priv->num_frags; i++) {
-		const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
-
-		page_alloc = &ring->page_alloc[i];
-		en_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
-		       i, page_count(page_alloc->page));
-
-		dma_unmap_page(priv->ddev, page_alloc->dma,
+	if (frag->page) {
+		dma_unmap_page(priv->ddev, frag->dma,
 			       PAGE_SIZE, priv->dma_dir);
-		while (page_alloc->page_offset + frag_info->frag_stride <
-		       PAGE_SIZE) {
-			put_page(page_alloc->page);
-			page_alloc->page_offset += frag_info->frag_stride;
-		}
-		page_alloc->page = NULL;
+		__free_page(frag->page);
 	}
+	/* We need to clear all fields, otherwise a change of priv->log_rx_info
+	 * could lead to see garbage later in frag->page.
+	 */
+	memset(frag, 0, sizeof(*frag));
 }
 
-static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
+static void mlx4_en_init_rx_desc(const struct mlx4_en_priv *priv,
 				 struct mlx4_en_rx_ring *ring, int index)
 {
 	struct mlx4_en_rx_desc *rx_desc = ring->buf + ring->stride * index;
@@ -235,19 +135,22 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 					(index << priv->log_rx_info);
 
 	if (ring->page_cache.index > 0) {
-		ring->page_cache.index--;
-		frags[0].page = ring->page_cache.buf[ring->page_cache.index].page;
-		frags[0].dma  = ring->page_cache.buf[ring->page_cache.index].dma;
-		frags[0].page_offset = XDP_PACKET_HEADROOM;
-		rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
-						    frags[0].page_offset);
+		/* XDP uses a single page per frame */
+		if (!frags->page) {
+			ring->page_cache.index--;
+			frags->page = ring->page_cache.buf[ring->page_cache.index].page;
+			frags->dma  = ring->page_cache.buf[ring->page_cache.index].dma;
+		}
+		frags->page_offset = XDP_PACKET_HEADROOM;
+		rx_desc->data[0].addr = cpu_to_be64(frags->dma +
+						    XDP_PACKET_HEADROOM);
 		return 0;
 	}
 
-	return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc, gfp);
+	return mlx4_en_alloc_frags(priv, rx_desc, frags, gfp);
 }
 
-static inline bool mlx4_en_is_ring_empty(struct mlx4_en_rx_ring *ring)
+static bool mlx4_en_is_ring_empty(const struct mlx4_en_rx_ring *ring)
 {
 	return ring->prod == ring->cons;
 }
@@ -257,7 +160,8 @@ static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
 	*ring->wqres.db.db = cpu_to_be32(ring->prod & 0xffff);
 }
 
-static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
+/* slow path */
+static void mlx4_en_free_rx_desc(const struct mlx4_en_priv *priv,
 				 struct mlx4_en_rx_ring *ring,
 				 int index)
 {
@@ -267,7 +171,7 @@ static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
 	frags = ring->rx_info + (index << priv->log_rx_info);
 	for (nr = 0; nr < priv->num_frags; nr++) {
 		en_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
-		mlx4_en_free_frag(priv, frags, nr);
+		mlx4_en_free_frag(priv, frags + nr);
 	}
 }
 
@@ -323,12 +227,12 @@ static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
 	       ring->cons, ring->prod);
 
 	/* Unmap and free Rx buffers */
-	while (!mlx4_en_is_ring_empty(ring)) {
-		index = ring->cons & ring->size_mask;
+	for (index = 0; index < ring->size; index++) {
 		en_dbg(DRV, priv, "Processing descriptor:%d\n", index);
 		mlx4_en_free_rx_desc(priv, ring, index);
-		++ring->cons;
 	}
+	ring->cons = 0;
+	ring->prod = 0;
 }
 
 void mlx4_en_set_num_rx_rings(struct mlx4_en_dev *mdev)
@@ -380,9 +284,9 @@ int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
 
 	tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
 					sizeof(struct mlx4_en_rx_alloc));
-	ring->rx_info = vmalloc_node(tmp, node);
+	ring->rx_info = vzalloc_node(tmp, node);
 	if (!ring->rx_info) {
-		ring->rx_info = vmalloc(tmp);
+		ring->rx_info = vzalloc(tmp);
 		if (!ring->rx_info) {
 			err = -ENOMEM;
 			goto err_ring;
@@ -452,16 +356,6 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
 		/* Initialize all descriptors */
 		for (i = 0; i < ring->size; i++)
 			mlx4_en_init_rx_desc(priv, ring, i);
-
-		/* Initialize page allocators */
-		err = mlx4_en_init_allocator(priv, ring);
-		if (err) {
-			en_err(priv, "Failed initializing ring allocator\n");
-			if (ring->stride <= TXBB_SIZE)
-				ring->buf -= TXBB_SIZE;
-			ring_ind--;
-			goto err_allocator;
-		}
 	}
 	err = mlx4_en_fill_rx_buffers(priv);
 	if (err)
@@ -481,11 +375,9 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
 		mlx4_en_free_rx_buf(priv, priv->rx_ring[ring_ind]);
 
 	ring_ind = priv->rx_ring_num - 1;
-err_allocator:
 	while (ring_ind >= 0) {
 		if (priv->rx_ring[ring_ind]->stride <= TXBB_SIZE)
 			priv->rx_ring[ring_ind]->buf -= TXBB_SIZE;
-		mlx4_en_destroy_allocator(priv, priv->rx_ring[ring_ind]);
 		ring_ind--;
 	}
 	return err;
@@ -565,50 +457,68 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
 	mlx4_en_free_rx_buf(priv, ring);
 	if (ring->stride <= TXBB_SIZE)
 		ring->buf -= TXBB_SIZE;
-	mlx4_en_destroy_allocator(priv, ring);
 }
 
 
 static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
-				    struct mlx4_en_rx_desc *rx_desc,
 				    struct mlx4_en_rx_alloc *frags,
 				    struct sk_buff *skb,
 				    int length)
 {
-	struct skb_frag_struct *skb_frags_rx = skb_shinfo(skb)->frags;
-	struct mlx4_en_frag_info *frag_info = priv->frag_info;
+	const struct mlx4_en_frag_info *frag_info = priv->frag_info;
+	unsigned int truesize = 0;
 	int nr, frag_size;
+	struct page *page;
 	dma_addr_t dma;
+	bool release;
 
 	/* Collect used fragments while replacing them in the HW descriptors */
-	for (nr = 0;;) {
+	for (nr = 0;; frags++) {
 		frag_size = min_t(int, length, frag_info->frag_size);
 
-		if (unlikely(!frags[nr].page))
+		page = frags->page;
+		if (unlikely(!page))
 			goto fail;
 
-		dma = be64_to_cpu(rx_desc->data[nr].addr);
-		dma_sync_single_for_cpu(priv->ddev, dma, frag_info->frag_size,
-					DMA_FROM_DEVICE);
+		dma = frags->dma;
+		dma_sync_single_range_for_cpu(priv->ddev, dma, frags->page_offset,
+					      frag_size, priv->dma_dir);
 
-		__skb_fill_page_desc(skb, nr, frags[nr].page,
-				     frags[nr].page_offset,
+		__skb_fill_page_desc(skb, nr, page, frags->page_offset,
 				     frag_size);
 
-		skb->truesize += frag_info->frag_stride;
-		frags[nr].page = NULL;
+		truesize += frag_info->frag_stride;
+		if (frag_info->frag_stride == PAGE_SIZE / 2) {
+			frags->page_offset ^= PAGE_SIZE / 2;
+			release = page_count(page) != 1 ||
+				  page_is_pfmemalloc(page) ||
+				  page_to_nid(page) != numa_mem_id();
+		} else {
+			u32 sz_align = ALIGN(frag_size, SMP_CACHE_BYTES);
+
+			frags->page_offset += sz_align;
+			release = frags->page_offset + frag_info->frag_size > PAGE_SIZE;
+		}
+		if (release) {
+			dma_unmap_page(priv->ddev, dma, PAGE_SIZE, priv->dma_dir);
+			frags->page = NULL;
+		} else {
+			page_ref_inc(page);
+		}
+
 		nr++;
 		length -= frag_size;
 		if (!length)
 			break;
 		frag_info++;
 	}
+	skb->truesize += truesize;
 	return nr;
 
 fail:
 	while (nr > 0) {
 		nr--;
-		__skb_frag_unref(&skb_frags_rx[nr]);
+		__skb_frag_unref(skb_shinfo(skb)->frags + nr);
 	}
 	return 0;
 }
@@ -639,7 +549,8 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
 	if (length <= SMALL_PACKET_SIZE) {
 		/* We are copying all relevant data to the skb - temporarily
 		 * sync buffers for the copy */
-		dma = be64_to_cpu(rx_desc->data[0].addr);
+
+		dma = frags[0].dma + frags[0].page_offset;
 		dma_sync_single_for_cpu(priv->ddev, dma, length,
 					DMA_FROM_DEVICE);
 		skb_copy_to_linear_data(skb, va, length);
@@ -648,7 +559,7 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
 		unsigned int pull_len;
 
 		/* Move relevant fragments to skb */
-		used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, frags,
+		used_frags = mlx4_en_complete_rx_desc(priv, frags,
 							skb, length);
 		if (unlikely(!used_frags)) {
 			kfree_skb(skb);
@@ -916,8 +827,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_TX:
 				if (likely(!mlx4_en_xmit_frame(ring, frags, dev,
 							length, cq->ring,
-							&doorbell_pending)))
-					goto consumed;
+							&doorbell_pending))) {
+					frags[0].page = NULL;
+					goto next;
+				}
 				trace_xdp_exception(dev, xdp_prog, act);
 				goto xdp_drop_no_cnt; /* Drop on xmit failure */
 			default:
@@ -927,8 +840,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			case XDP_DROP:
 				ring->xdp_drop++;
 xdp_drop_no_cnt:
-				if (likely(mlx4_en_rx_recycle(ring, frags)))
-					goto consumed;
 				goto next;
 			}
 		}
@@ -974,9 +885,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			if (!gro_skb)
 				goto next;
 
-			nr = mlx4_en_complete_rx_desc(priv,
-				rx_desc, frags, gro_skb,
-				length);
+			nr = mlx4_en_complete_rx_desc(priv, frags, gro_skb,
+						      length);
 			if (!nr)
 				goto next;
 
@@ -1084,10 +994,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 
 		napi_gro_receive(&cq->napi, skb);
 next:
-		for (nr = 0; nr < priv->num_frags; nr++)
-			mlx4_en_free_frag(priv, frags, nr);
-
-consumed:
 		++cq->mcq.cons_index;
 		index = (cq->mcq.cons_index) & ring->size_mask;
 		cqe = mlx4_en_get_cqe(cq->buf, index, priv->cqe_size) + factor;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 6c80117006edf25de46fe60fd36051ee9b10d3cb..5f608026698100c9746aac9bbbafe9e3c8b86c2d 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -327,7 +327,6 @@ struct mlx4_en_rx_desc {
 
 struct mlx4_en_rx_ring {
 	struct mlx4_hwq_resources wqres;
-	struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
 	u32 size ;	/* number of Rx descs*/
 	u32 actual_size;
 	u32 size_mask;
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 09/13] mlx4: add rx_alloc_pages counter in ethtool -S

[Eric Dumazet]

This new counter tracks number of pages that we allocated for one port.

lpaa24:~# ethtool -S eth0 | egrep 'rx_alloc_pages|rx_packets'
     rx_packets: 306755183
     rx_alloc_pages: 932897

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c |  2 +-
 drivers/net/ethernet/mellanox/mlx4/en_port.c    |  2 ++
 drivers/net/ethernet/mellanox/mlx4/en_rx.c      | 11 +++++++----
 drivers/net/ethernet/mellanox/mlx4/mlx4_en.h    |  1 +
 drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h |  2 +-
 5 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index c4d714fcc7dae759998a49a1f90f9ab1ee9bdda3..ffbcb27c05e55f43630a812249bab21609886dd9 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -117,7 +117,7 @@ static const char main_strings[][ETH_GSTRING_LEN] = {
 	/* port statistics */
 	"tso_packets",
 	"xmit_more",
-	"queue_stopped", "wake_queue", "tx_timeout", "rx_alloc_failed",
+	"queue_stopped", "wake_queue", "tx_timeout", "rx_alloc_pages",
 	"rx_csum_good", "rx_csum_none", "rx_csum_complete", "tx_chksum_offload",
 
 	/* pf statistics */
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_port.c b/drivers/net/ethernet/mellanox/mlx4/en_port.c
index 9166d90e732858610b1407fe85cbf6cbe27f5e0b..e0eb695318e64ebcaf58d6edb5f9a57be6f9ddf6 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_port.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_port.c
@@ -213,6 +213,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset)
 	priv->port_stats.rx_chksum_good = 0;
 	priv->port_stats.rx_chksum_none = 0;
 	priv->port_stats.rx_chksum_complete = 0;
+	priv->port_stats.rx_alloc_pages = 0;
 	priv->xdp_stats.rx_xdp_drop    = 0;
 	priv->xdp_stats.rx_xdp_tx      = 0;
 	priv->xdp_stats.rx_xdp_tx_full = 0;
@@ -223,6 +224,7 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset)
 		priv->port_stats.rx_chksum_good += READ_ONCE(ring->csum_ok);
 		priv->port_stats.rx_chksum_none += READ_ONCE(ring->csum_none);
 		priv->port_stats.rx_chksum_complete += READ_ONCE(ring->csum_complete);
+		priv->port_stats.rx_alloc_pages += READ_ONCE(ring->rx_alloc_pages);
 		priv->xdp_stats.rx_xdp_drop	+= READ_ONCE(ring->xdp_drop);
 		priv->xdp_stats.rx_xdp_tx	+= READ_ONCE(ring->xdp_tx);
 		priv->xdp_stats.rx_xdp_tx_full	+= READ_ONCE(ring->xdp_tx_full);
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 5edd0cf2999cbde37b3404aafd700584696af940..d3a425fa46b3924411e42a865b3a57aa063f1635 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -72,6 +72,7 @@ static int mlx4_alloc_page(struct mlx4_en_priv *priv,
 }
 
 static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
+			       struct mlx4_en_rx_ring *ring,
 			       struct mlx4_en_rx_desc *rx_desc,
 			       struct mlx4_en_rx_alloc *frags,
 			       gfp_t gfp)
@@ -79,8 +80,11 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
 	int i;
 
 	for (i = 0; i < priv->num_frags; i++, frags++) {
-		if (!frags->page && mlx4_alloc_page(priv, frags, gfp))
-			return -ENOMEM;
+		if (!frags->page) {
+			if (mlx4_alloc_page(priv, frags, gfp))
+				return -ENOMEM;
+			ring->rx_alloc_pages++;
+		}
 		rx_desc->data[i].addr = cpu_to_be64(frags->dma +
 						    frags->page_offset);
 	}
@@ -133,7 +137,6 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 	struct mlx4_en_rx_desc *rx_desc = ring->buf + (index * ring->stride);
 	struct mlx4_en_rx_alloc *frags = ring->rx_info +
 					(index << priv->log_rx_info);
-
 	if (ring->page_cache.index > 0) {
 		/* XDP uses a single page per frame */
 		if (!frags->page) {
@@ -147,7 +150,7 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
 		return 0;
 	}
 
-	return mlx4_en_alloc_frags(priv, rx_desc, frags, gfp);
+	return mlx4_en_alloc_frags(priv, ring, rx_desc, frags, gfp);
 }
 
 static bool mlx4_en_is_ring_empty(const struct mlx4_en_rx_ring *ring)
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 5f608026698100c9746aac9bbbafe9e3c8b86c2d..39f401aa30474e61c0b0029463b23a829ec35fa3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -346,6 +346,7 @@ struct mlx4_en_rx_ring {
 	unsigned long csum_ok;
 	unsigned long csum_none;
 	unsigned long csum_complete;
+	unsigned long rx_alloc_pages;
 	unsigned long xdp_drop;
 	unsigned long xdp_tx;
 	unsigned long xdp_tx_full;
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h
index 48641cb0367f251a07537b82d0a16bf50d8479ef..926f3c3f3665c5d28fe5d35c41afaa0e5917c007 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h
@@ -37,7 +37,7 @@ struct mlx4_en_port_stats {
 	unsigned long queue_stopped;
 	unsigned long wake_queue;
 	unsigned long tx_timeout;
-	unsigned long rx_alloc_failed;
+	unsigned long rx_alloc_pages;
 	unsigned long rx_chksum_good;
 	unsigned long rx_chksum_none;
 	unsigned long rx_chksum_complete;
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 10/13] mlx4: do not access rx_desc from mlx4_en_process_rx_cq()

[Eric Dumazet]

Instead of fetching dma address from rx_desc->data[0].addr,
prefer using frags[0].dma + frags[0].page_offset to avoid
a potential cache line miss.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index d3a425fa46b3924411e42a865b3a57aa063f1635..b62fa265890edd0eff50256bdc50fc907dbe8aa2 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -528,7 +528,6 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
 
 
 static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
-				      struct mlx4_en_rx_desc *rx_desc,
 				      struct mlx4_en_rx_alloc *frags,
 				      unsigned int length)
 {
@@ -703,7 +702,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	struct mlx4_cqe *cqe;
 	struct mlx4_en_rx_ring *ring = priv->rx_ring[cq->ring];
 	struct mlx4_en_rx_alloc *frags;
-	struct mlx4_en_rx_desc *rx_desc;
 	struct bpf_prog *xdp_prog;
 	int doorbell_pending;
 	struct sk_buff *skb;
@@ -738,7 +736,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		    cq->mcq.cons_index & cq->size)) {
 
 		frags = ring->rx_info + (index << priv->log_rx_info);
-		rx_desc = ring->buf + (index << ring->log_stride);
 
 		/*
 		 * make sure we read the CQE after we read the ownership bit
@@ -767,7 +764,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			/* Get pointer to first fragment since we haven't
 			 * skb yet and cast it to ethhdr struct
 			 */
-			dma = be64_to_cpu(rx_desc->data[0].addr);
+			dma = frags[0].dma + frags[0].page_offset;
 			dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
 						DMA_FROM_DEVICE);
 			ethh = (struct ethhdr *)(page_address(frags[0].page) +
@@ -806,7 +803,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			void *orig_data;
 			u32 act;
 
-			dma = be64_to_cpu(rx_desc->data[0].addr);
+			dma = frags[0].dma + frags[0].page_offset;
 			dma_sync_single_for_cpu(priv->ddev, dma,
 						priv->frag_info[0].frag_size,
 						DMA_FROM_DEVICE);
@@ -946,7 +943,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		}
 
 		/* GRO not possible, complete processing here */
-		skb = mlx4_en_rx_skb(priv, rx_desc, frags, length);
+		skb = mlx4_en_rx_skb(priv, frags, length);
 		if (unlikely(!skb)) {
 			ring->dropped++;
 			goto next;
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 11/13] mlx4: factorize page_address() calls

[Eric Dumazet]

We need to compute the frame virtual address at different points.
Do it once.

Following patch will use the new va address for validate_loopback()

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index b62fa265890edd0eff50256bdc50fc907dbe8aa2..b5aa3f986508f0a5a89a40e18f8db99767068fef 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -734,9 +734,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	/* Process all completed CQEs */
 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
 		    cq->mcq.cons_index & cq->size)) {
+		void *va;
 
 		frags = ring->rx_info + (index << priv->log_rx_info);
-
+		va = page_address(frags[0].page) + frags[0].page_offset;
 		/*
 		 * make sure we read the CQE after we read the ownership bit
 		 */
@@ -759,7 +760,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		 * and not performing the selftest or flb disabled
 		 */
 		if (priv->flags & MLX4_EN_FLAG_RX_FILTER_NEEDED) {
-			struct ethhdr *ethh;
+			const struct ethhdr *ethh = va;
 			dma_addr_t dma;
 			/* Get pointer to first fragment since we haven't
 			 * skb yet and cast it to ethhdr struct
@@ -767,8 +768,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			dma = frags[0].dma + frags[0].page_offset;
 			dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
 						DMA_FROM_DEVICE);
-			ethh = (struct ethhdr *)(page_address(frags[0].page) +
-						 frags[0].page_offset);
 
 			if (is_multicast_ether_addr(ethh->h_dest)) {
 				struct mlx4_mac_entry *entry;
@@ -808,8 +807,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 						priv->frag_info[0].frag_size,
 						DMA_FROM_DEVICE);
 
-			xdp.data_hard_start = page_address(frags[0].page);
-			xdp.data = xdp.data_hard_start + frags[0].page_offset;
+			xdp.data_hard_start = va - frags[0].page_offset;
+			xdp.data = va;
 			xdp.data_end = xdp.data + length;
 			orig_data = xdp.data;
 
@@ -819,6 +818,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 				length = xdp.data_end - xdp.data;
 				frags[0].page_offset = xdp.data -
 					xdp.data_hard_start;
+				va = xdp.data;
 			}
 
 			switch (act) {
@@ -891,7 +891,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 				goto next;
 
 			if (ip_summed == CHECKSUM_COMPLETE) {
-				void *va = skb_frag_address(skb_shinfo(gro_skb)->frags);
 				if (check_csum(cqe, gro_skb, va,
 					       dev->features)) {
 					ip_summed = CHECKSUM_NONE;
@@ -955,7 +954,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		}
 
 		if (ip_summed == CHECKSUM_COMPLETE) {
-			if (check_csum(cqe, skb, skb->data, dev->features)) {
+			if (check_csum(cqe, skb, va, dev->features)) {
 				ip_summed = CHECKSUM_NONE;
 				ring->csum_complete--;
 				ring->csum_none++;
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 12/13] mlx4: make validate_loopback() more generic

[Eric Dumazet]

Testing a boolean in fast path is not worth duplicating
the code allocating packets, when GRO is on or off.

If this proves to be a problem, we might later use a jump label.

Next patch will remove this duplicated code and ease code review.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c       | 23 ++++++++++-------------
 drivers/net/ethernet/mellanox/mlx4/en_selftest.c |  6 ------
 2 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index b5aa3f986508f0a5a89a40e18f8db99767068fef..33b28278c8270197c5a8f35521fd2af5e1e6b1be 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -584,20 +584,17 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
 	return skb;
 }
 
-static void validate_loopback(struct mlx4_en_priv *priv, struct sk_buff *skb)
+static void validate_loopback(struct mlx4_en_priv *priv, void *va)
 {
+	const unsigned char *data = va + ETH_HLEN;
 	int i;
-	int offset = ETH_HLEN;
 
-	for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++, offset++) {
-		if (*(skb->data + offset) != (unsigned char) (i & 0xff))
-			goto out_loopback;
+	for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++) {
+		if (data[i] != (unsigned char)i)
+			return;
 	}
 	/* Loopback found */
 	priv->loopback_ok = 1;
-
-out_loopback:
-	dev_kfree_skb_any(skb);
 }
 
 static bool mlx4_en_refill_rx_buffers(struct mlx4_en_priv *priv,
@@ -785,6 +782,11 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			}
 		}
 
+		if (unlikely(priv->validate_loopback)) {
+			validate_loopback(priv, va);
+			goto next;
+		}
+
 		/*
 		 * Packet is OK - process it.
 		 */
@@ -948,11 +950,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			goto next;
 		}
 
-		if (unlikely(priv->validate_loopback)) {
-			validate_loopback(priv, skb);
-			goto next;
-		}
-
 		if (ip_summed == CHECKSUM_COMPLETE) {
 			if (check_csum(cqe, skb, va, dev->features)) {
 				ip_summed = CHECKSUM_NONE;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_selftest.c b/drivers/net/ethernet/mellanox/mlx4/en_selftest.c
index 95290e1fc9fe7600b2e3bcca334f3fad7d733c09..17112faafbccc5f7a75ee82a287be7952859ae9e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_selftest.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_selftest.c
@@ -81,14 +81,11 @@ static int mlx4_en_test_loopback(struct mlx4_en_priv *priv)
 {
 	u32 loopback_ok = 0;
 	int i;
-	bool gro_enabled;
 
         priv->loopback_ok = 0;
 	priv->validate_loopback = 1;
-	gro_enabled = priv->dev->features & NETIF_F_GRO;
 
 	mlx4_en_update_loopback_state(priv->dev, priv->dev->features);
-	priv->dev->features &= ~NETIF_F_GRO;
 
 	/* xmit */
 	if (mlx4_en_test_loopback_xmit(priv)) {
@@ -111,9 +108,6 @@ static int mlx4_en_test_loopback(struct mlx4_en_priv *priv)
 
 	priv->validate_loopback = 0;
 
-	if (gro_enabled)
-		priv->dev->features |= NETIF_F_GRO;
-
 	mlx4_en_update_loopback_state(priv->dev, priv->dev->features);
 	return !loopback_ok;
 }
-- 
2.12.0.246.ga2ecc84866-goog

[PATCH v4 net-next 13/13] mlx4: remove duplicate code in mlx4_en_process_rx_cq()

[Eric Dumazet]

We should keep one way to build skbs, regardless of GRO being on or off.

Note that I made sure to defer as much as possible the point we need to
pull data from the frame, so that future prefetch() we might add
are more effective.

These skb attributes derive from the CQE or ring :
 ip_summed, csum
 hash
 vlan offload
 hwtstamps
 queue_mapping

As a bonus, this patch removes mlx4 dependency on eth_get_headlen()
which is very often broken enough to give us headaches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_rx.c | 209 ++++++-----------------------
 1 file changed, 41 insertions(+), 168 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 33b28278c8270197c5a8f35521fd2af5e1e6b1be..aa074e57ce06fb2842fa1faabd156c3cd2fe10f5 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -526,64 +526,6 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
 	return 0;
 }
 
-
-static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
-				      struct mlx4_en_rx_alloc *frags,
-				      unsigned int length)
-{
-	struct sk_buff *skb;
-	void *va;
-	int used_frags;
-	dma_addr_t dma;
-
-	skb = netdev_alloc_skb(priv->dev, SMALL_PACKET_SIZE + NET_IP_ALIGN);
-	if (unlikely(!skb)) {
-		en_dbg(RX_ERR, priv, "Failed allocating skb\n");
-		return NULL;
-	}
-	skb_reserve(skb, NET_IP_ALIGN);
-	skb->len = length;
-
-	/* Get pointer to first fragment so we could copy the headers into the
-	 * (linear part of the) skb */
-	va = page_address(frags[0].page) + frags[0].page_offset;
-
-	if (length <= SMALL_PACKET_SIZE) {
-		/* We are copying all relevant data to the skb - temporarily
-		 * sync buffers for the copy */
-
-		dma = frags[0].dma + frags[0].page_offset;
-		dma_sync_single_for_cpu(priv->ddev, dma, length,
-					DMA_FROM_DEVICE);
-		skb_copy_to_linear_data(skb, va, length);
-		skb->tail += length;
-	} else {
-		unsigned int pull_len;
-
-		/* Move relevant fragments to skb */
-		used_frags = mlx4_en_complete_rx_desc(priv, frags,
-							skb, length);
-		if (unlikely(!used_frags)) {
-			kfree_skb(skb);
-			return NULL;
-		}
-		skb_shinfo(skb)->nr_frags = used_frags;
-
-		pull_len = eth_get_headlen(va, SMALL_PACKET_SIZE);
-		/* Copy headers into the skb linear buffer */
-		memcpy(skb->data, va, pull_len);
-		skb->tail += pull_len;
-
-		/* Skip headers in first fragment */
-		skb_shinfo(skb)->frags[0].page_offset += pull_len;
-
-		/* Adjust size of first fragment */
-		skb_frag_size_sub(&skb_shinfo(skb)->frags[0], pull_len);
-		skb->data_len = length - pull_len;
-	}
-	return skb;
-}
-
 static void validate_loopback(struct mlx4_en_priv *priv, void *va)
 {
 	const unsigned char *data = va + ETH_HLEN;
@@ -792,8 +734,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		 */
 		length = be32_to_cpu(cqe->byte_cnt);
 		length -= ring->fcs_del;
-		l2_tunnel = (dev->hw_enc_features & NETIF_F_RXCSUM) &&
-			(cqe->vlan_my_qpn & cpu_to_be32(MLX4_CQE_L2_TUNNEL));
 
 		/* A bpf program gets first chance to drop the packet. It may
 		 * read bytes but not past the end of the frag.
@@ -849,122 +789,51 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 		ring->bytes += length;
 		ring->packets++;
 
+		skb = napi_get_frags(&cq->napi);
+		if (!skb)
+			goto next;
+
+		if (unlikely(ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL)) {
+			timestamp = mlx4_en_get_cqe_ts(cqe);
+			mlx4_en_fill_hwtstamps(mdev, skb_hwtstamps(skb),
+					       timestamp);
+		}
+		skb_record_rx_queue(skb, cq->ring);
+
 		if (likely(dev->features & NETIF_F_RXCSUM)) {
 			if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_TCP |
 						      MLX4_CQE_STATUS_UDP)) {
 				if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
 				    cqe->checksum == cpu_to_be16(0xffff)) {
 					ip_summed = CHECKSUM_UNNECESSARY;
+					l2_tunnel = (dev->hw_enc_features & NETIF_F_RXCSUM) &&
+						(cqe->vlan_my_qpn & cpu_to_be32(MLX4_CQE_L2_TUNNEL));
+					if (l2_tunnel)
+						skb->csum_level = 1;
 					ring->csum_ok++;
 				} else {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
+					goto csum_none;
 				}
 			} else {
 				if (priv->flags & MLX4_EN_FLAG_RX_CSUM_NON_TCP_UDP &&
 				    (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4 |
 							       MLX4_CQE_STATUS_IPV6))) {
-					ip_summed = CHECKSUM_COMPLETE;
-					ring->csum_complete++;
+					if (check_csum(cqe, skb, va, dev->features)) {
+						goto csum_none;
+					} else {
+						ip_summed = CHECKSUM_COMPLETE;
+						ring->csum_complete++;
+					}
 				} else {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
+					goto csum_none;
 				}
 			}
 		} else {
+csum_none:
 			ip_summed = CHECKSUM_NONE;
 			ring->csum_none++;
 		}
-
-		/* This packet is eligible for GRO if it is:
-		 * - DIX Ethernet (type interpretation)
-		 * - TCP/IP (v4)
-		 * - without IP options
-		 * - not an IP fragment
-		 */
-		if (dev->features & NETIF_F_GRO) {
-			struct sk_buff *gro_skb = napi_get_frags(&cq->napi);
-			if (!gro_skb)
-				goto next;
-
-			nr = mlx4_en_complete_rx_desc(priv, frags, gro_skb,
-						      length);
-			if (!nr)
-				goto next;
-
-			if (ip_summed == CHECKSUM_COMPLETE) {
-				if (check_csum(cqe, gro_skb, va,
-					       dev->features)) {
-					ip_summed = CHECKSUM_NONE;
-					ring->csum_none++;
-					ring->csum_complete--;
-				}
-			}
-
-			skb_shinfo(gro_skb)->nr_frags = nr;
-			gro_skb->len = length;
-			gro_skb->data_len = length;
-			gro_skb->ip_summed = ip_summed;
-
-			if (l2_tunnel && ip_summed == CHECKSUM_UNNECESSARY)
-				gro_skb->csum_level = 1;
-
-			if ((cqe->vlan_my_qpn &
-			    cpu_to_be32(MLX4_CQE_CVLAN_PRESENT_MASK)) &&
-			    (dev->features & NETIF_F_HW_VLAN_CTAG_RX)) {
-				u16 vid = be16_to_cpu(cqe->sl_vid);
-
-				__vlan_hwaccel_put_tag(gro_skb, htons(ETH_P_8021Q), vid);
-			} else if ((be32_to_cpu(cqe->vlan_my_qpn) &
-				  MLX4_CQE_SVLAN_PRESENT_MASK) &&
-				 (dev->features & NETIF_F_HW_VLAN_STAG_RX)) {
-				__vlan_hwaccel_put_tag(gro_skb,
-						       htons(ETH_P_8021AD),
-						       be16_to_cpu(cqe->sl_vid));
-			}
-
-			if (dev->features & NETIF_F_RXHASH)
-				skb_set_hash(gro_skb,
-					     be32_to_cpu(cqe->immed_rss_invalid),
-					     (ip_summed == CHECKSUM_UNNECESSARY) ?
-						PKT_HASH_TYPE_L4 :
-						PKT_HASH_TYPE_L3);
-
-			skb_record_rx_queue(gro_skb, cq->ring);
-
-			if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
-				timestamp = mlx4_en_get_cqe_ts(cqe);
-				mlx4_en_fill_hwtstamps(mdev,
-						       skb_hwtstamps(gro_skb),
-						       timestamp);
-			}
-
-			napi_gro_frags(&cq->napi);
-			goto next;
-		}
-
-		/* GRO not possible, complete processing here */
-		skb = mlx4_en_rx_skb(priv, frags, length);
-		if (unlikely(!skb)) {
-			ring->dropped++;
-			goto next;
-		}
-
-		if (ip_summed == CHECKSUM_COMPLETE) {
-			if (check_csum(cqe, skb, va, dev->features)) {
-				ip_summed = CHECKSUM_NONE;
-				ring->csum_complete--;
-				ring->csum_none++;
-			}
-		}
-
 		skb->ip_summed = ip_summed;
-		skb->protocol = eth_type_trans(skb, dev);
-		skb_record_rx_queue(skb, cq->ring);
-
-		if (l2_tunnel && ip_summed == CHECKSUM_UNNECESSARY)
-			skb->csum_level = 1;
-
 		if (dev->features & NETIF_F_RXHASH)
 			skb_set_hash(skb,
 				     be32_to_cpu(cqe->immed_rss_invalid),
@@ -972,32 +841,36 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 					PKT_HASH_TYPE_L4 :
 					PKT_HASH_TYPE_L3);
 
-		if ((be32_to_cpu(cqe->vlan_my_qpn) &
-		    MLX4_CQE_CVLAN_PRESENT_MASK) &&
+
+		if ((cqe->vlan_my_qpn &
+		     cpu_to_be32(MLX4_CQE_CVLAN_PRESENT_MASK)) &&
 		    (dev->features & NETIF_F_HW_VLAN_CTAG_RX))
-			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), be16_to_cpu(cqe->sl_vid));
-		else if ((be32_to_cpu(cqe->vlan_my_qpn) &
-			  MLX4_CQE_SVLAN_PRESENT_MASK) &&
+			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
+					       be16_to_cpu(cqe->sl_vid));
+		else if ((cqe->vlan_my_qpn &
+			  cpu_to_be32(MLX4_CQE_SVLAN_PRESENT_MASK)) &&
 			 (dev->features & NETIF_F_HW_VLAN_STAG_RX))
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD),
 					       be16_to_cpu(cqe->sl_vid));
 
-		if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
-			timestamp = mlx4_en_get_cqe_ts(cqe);
-			mlx4_en_fill_hwtstamps(mdev, skb_hwtstamps(skb),
-					       timestamp);
+		nr = mlx4_en_complete_rx_desc(priv, frags, skb, length);
+		if (likely(nr)) {
+			skb_shinfo(skb)->nr_frags = nr;
+			skb->len = length;
+			skb->data_len = length;
+			napi_gro_frags(&cq->napi);
+		} else {
+			skb->vlan_tci = 0;
+			skb_clear_hash(skb);
 		}
-
-		napi_gro_receive(&cq->napi, skb);
 next:
 		++cq->mcq.cons_index;
 		index = (cq->mcq.cons_index) & ring->size_mask;
 		cqe = mlx4_en_get_cqe(cq->buf, index, priv->cqe_size) + factor;
 		if (++polled == budget)
-			goto out;
+			break;
 	}
 
-out:
 	rcu_read_unlock();
 
 	if (polled) {
-- 
2.12.0.246.ga2ecc84866-goog

Re: [PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> As mentioned half a year ago, we better switch mlx4 driver to order-0
> allocations and page recycling.
>
> This reduces vulnerability surface thanks to better skb->truesize
> tracking and provides better performance in most cases.
> (33 Gbit for one TCP flow on my lab hosts)
>
> I will provide for linux-4.13 a patch on top of this series,
> trying to improve data locality as described in
> https://www.spinics.net/lists/netdev/msg422258.html
>
> v2 provides an ethtool -S new counter (rx_alloc_pages) and
> code factorization, plus Tariq fix.
>
> v3 includes various fixes based on Tariq tests and feedback
> from Saeed and Tariq.
>
> v4 rebased on net-next for inclusion in linux-4.12, as requested
> by Tariq.
>
Hi Eric,

I was preparing this series for submission as well.
You got it done first :)

Thanks for re-submitting.
I am Acking the patches now.

Regards,
Tariq

> Worth noting this patch series deletes ~250 lines of code ;)
>
> Eric Dumazet (13):
>   mlx4: dma_dir is a mlx4_en_priv attribute
>   mlx4: remove order field from mlx4_en_frag_info
>   mlx4: get rid of frag_prefix_size
>   mlx4: rx_headroom is a per port attribute
>   mlx4: reduce rx ring page_cache size
>   mlx4: removal of frag_sizes[]
>   mlx4: use order-0 pages for RX
>   mlx4: add page recycling in receive path
>   mlx4: add rx_alloc_pages counter in ethtool -S
>   mlx4: do not access rx_desc from mlx4_en_process_rx_cq()
>   mlx4: factorize page_address() calls
>   mlx4: make validate_loopback() more generic
>   mlx4: remove duplicate code in mlx4_en_process_rx_cq()
>
>  drivers/net/ethernet/mellanox/mlx4/en_ethtool.c  |   2 +-
>  drivers/net/ethernet/mellanox/mlx4/en_port.c     |   2 +
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c       | 607 +++++++----------------
>  drivers/net/ethernet/mellanox/mlx4/en_selftest.c |   6 -
>  drivers/net/ethernet/mellanox/mlx4/en_tx.c       |   4 +-
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h     |  30 +-
>  drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h  |   2 +-
>  7 files changed, 201 insertions(+), 452 deletions(-)
>

Re: [PATCH v4 net-next 01/13] mlx4: dma_dir is a mlx4_en_priv attribute

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> No need to duplicate it for all queues and frags.
>
> num_frags & log_rx_info become u8 to save space.
> u8 accesses are a bit faster than u16 anyway.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 16 ++++++++--------
>  drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  2 +-
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  6 +++---
>  3 files changed, 12 insertions(+), 12 deletions(-)
>

Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 02/13] mlx4: remove order field from mlx4_en_frag_info

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> This is really a port attribute, no need to duplicate it per
> RX queue and per frag.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 6 +++---
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 03/13] mlx4: get rid of frag_prefix_size

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> Using per frag storage for frag_prefix_size is really silly.
>
> mlx4_en_complete_rx_desc() has all needed info already.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 27 ++++++++++++---------------
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  3 +--
>  2 files changed, 13 insertions(+), 17 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 04/13] mlx4: rx_headroom is a per port attribute

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> No need to duplicate it per RX queue / frags.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 6 +++---
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 05/13] mlx4: reduce rx ring page_cache size

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> We only need to store the page and dma address.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 17 ++++++++++-------
>  drivers/net/ethernet/mellanox/mlx4/en_tx.c   |  2 --
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  6 +++++-
>  3 files changed, 15 insertions(+), 10 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 06/13] mlx4: removal of frag_sizes[]

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> We will soon use order-0 pages, and frag truesize will more precisely
> match real sizes.
>
> In the new model, we prefer to use <= 2048 bytes fragments, so that
> we can use page-recycle technique on PAGE_SIZE=4096 arches.
>
> We will still pack as much frames as possible on arches with big
> pages, like PowerPC.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 24 ++++++++++--------------
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  8 --------
>  2 files changed, 10 insertions(+), 22 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 07/13] mlx4: use order-0 pages for RX

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> Use of order-3 pages is problematic in some cases.
>
> This patch might add three kinds of regression :
>
> 1) a CPU performance regression, but we will add later page
> recycling and performance should be back.
>
> 2) TCP receiver could grow its receive window slightly slower,
>    because skb->len/skb->truesize ratio will decrease.
>    This is mostly ok, we prefer being conservative to not risk OOM,
>    and eventually tune TCP better in the future.
>    This is consistent with other drivers using 2048 per ethernet frame.
>
> 3) Because we allocate one page per RX slot, we consume more
>    memory for the ring buffers. XDP already had this constraint anyway.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 72 +++++++++++++---------------
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  5 --
>  2 files changed, 33 insertions(+), 44 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 08/13] mlx4: add page recycling in receive path

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> Same technique than some Intel drivers, for arches where PAGE_SIZE = 4096
>
> In most cases, pages are reused because they were consumed
> before we could loop around the RX ring.
>
> This brings back performance, and is even better,
> a single TCP flow reaches 30Gbit on my hosts.
>
> v2: added full memset() in mlx4_en_free_frag(), as Tariq found it was needed
> if we switch to large MTU, as priv->log_rx_info can dynamically be changed.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c   | 258 +++++++++------------------
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |   1 -
>  2 files changed, 82 insertions(+), 177 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 09/13] mlx4: add rx_alloc_pages counter in ethtool -S

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> This new counter tracks number of pages that we allocated for one port.
>
> lpaa24:~# ethtool -S eth0 | egrep 'rx_alloc_pages|rx_packets'
>      rx_packets: 306755183
>      rx_alloc_pages: 932897
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_ethtool.c |  2 +-
>  drivers/net/ethernet/mellanox/mlx4/en_port.c    |  2 ++
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c      | 11 +++++++----
>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h    |  1 +
>  drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h |  2 +-
>  5 files changed, 12 insertions(+), 6 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 10/13] mlx4: do not access rx_desc from mlx4_en_process_rx_cq()

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> Instead of fetching dma address from rx_desc->data[0].addr,
> prefer using frags[0].dma + frags[0].page_offset to avoid
> a potential cache line miss.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 11/13] mlx4: factorize page_address() calls

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> We need to compute the frame virtual address at different points.
> Do it once.
>
> Following patch will use the new va address for validate_loopback()
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 12/13] mlx4: make validate_loopback() more generic

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> Testing a boolean in fast path is not worth duplicating
> the code allocating packets, when GRO is on or off.
>
> If this proves to be a problem, we might later use a jump label.
>
> Next patch will remove this duplicated code and ease code review.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c       | 23 ++++++++++-------------
>  drivers/net/ethernet/mellanox/mlx4/en_selftest.c |  6 ------
>  2 files changed, 10 insertions(+), 19 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 13/13] mlx4: remove duplicate code in mlx4_en_process_rx_cq()

[Tariq Toukan]

On 08/03/2017 6:17 PM, Eric Dumazet wrote:
> We should keep one way to build skbs, regardless of GRO being on or off.
>
> Note that I made sure to defer as much as possible the point we need to
> pull data from the frame, so that future prefetch() we might add
> are more effective.
>
> These skb attributes derive from the CQE or ring :
>  ip_summed, csum
>  hash
>  vlan offload
>  hwtstamps
>  queue_mapping
>
> As a bonus, this patch removes mlx4 dependency on eth_get_headlen()
> which is very often broken enough to give us headaches.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c | 209 ++++++-----------------------
>  1 file changed, 41 insertions(+), 168 deletions(-)
>
Acked-by: Tariq Toukan <tariqt@mellanox.com>

Thanks.

Re: [PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[Eric Dumazet]

On Thu, Mar 9, 2017 at 5:49 AM, Tariq Toukan <tariqt@mellanox.com> wrote:

> Hi Eric,
>
> I was preparing this series for submission as well.
> You got it done first :)
>
> Thanks for re-submitting.
> I am Acking the patches now.

I believe you also could have added a single Ack on this cover,
instead of one ack per element in the series.

David can you tell us if this is true ?

Thanks Tariq !

Re: [PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[Tariq Toukan]

On 09/03/2017 4:26 PM, Eric Dumazet wrote:
> On Thu, Mar 9, 2017 at 5:49 AM, Tariq Toukan <tariqt@mellanox.com> wrote:
>
>> Hi Eric,
>>
>> I was preparing this series for submission as well.
>> You got it done first :)
>>
>> Thanks for re-submitting.
>> I am Acking the patches now.
>
> I believe you also could have added a single Ack on this cover,
> instead of one ack per element in the series.

I wasn't sure this is possible, I think patchworks doesn't recognize it.
Dave, does this work?

>
> David can you tell us if this is true ?
>
> Thanks Tariq !
>

You're welcome.

Re: [PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[David Miller]

From: Tariq Toukan <tariqt@mellanox.com>
Date: Thu, 9 Mar 2017 17:53:18 +0200

> 
> 
> On 09/03/2017 4:26 PM, Eric Dumazet wrote:
>> On Thu, Mar 9, 2017 at 5:49 AM, Tariq Toukan <tariqt@mellanox.com>
>> wrote:
>>
>>> Hi Eric,
>>>
>>> I was preparing this series for submission as well.
>>> You got it done first :)
>>>
>>> Thanks for re-submitting.
>>> I am Acking the patches now.
>>
>> I believe you also could have added a single Ack on this cover,
>> instead of one ack per element in the series.
> 
> I wasn't sure this is possible, I think patchworks doesn't recognize
> it.
> Dave, does this work?

If you ACK the cover letter, I add that ACK to the merge commit
for the patch series.  It is semantically equivalent to ACK'ing
the entire series.

Re: [PATCH v4 net-next 00/13] mlx4: order-0 allocations and page recycling

[David Miller]

From: Eric Dumazet <edumazet@google.com>
Date: Wed,  8 Mar 2017 08:17:05 -0800

> As mentioned half a year ago, we better switch mlx4 driver to order-0
> allocations and page recycling.
> 
> This reduces vulnerability surface thanks to better skb->truesize
> tracking and provides better performance in most cases.
> (33 Gbit for one TCP flow on my lab hosts)
> 
> I will provide for linux-4.13 a patch on top of this series,
> trying to improve data locality as described in
> https://www.spinics.net/lists/netdev/msg422258.html
> 
> v2 provides an ethtool -S new counter (rx_alloc_pages) and
> code factorization, plus Tariq fix.
> 
> v3 includes various fixes based on Tariq tests and feedback
> from Saeed and Tariq.
> 
> v4 rebased on net-next for inclusion in linux-4.12, as requested
> by Tariq.
> 
> Worth noting this patch series deletes ~250 lines of code ;)

Series applied, thanks everyone.