From 34db548bfb9580f33d9a7faecafe4da61a4428a3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 8 Mar 2017 08:17:13 -0800 Subject: mlx4: add page recycling in receive path 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 Acked-by: Tariq Toukan Signed-off-by: David S. Miller --- 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(-) (limited to 'drivers/net/ethernet/mellanox/mlx4') diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 069ea09185fb..5edd0cf2999c 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 @@ err_buffers: 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 @@ xdp_drop_no_cnt: 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 @@ xdp_drop_no_cnt: 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 6c80117006ed..5f6080266981 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; -- cgit v1.2.3-55-g7522