mirror of https://gitee.com/openkylin/linux.git
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 <edumazet@google.com> Acked-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
David S. Miller
parent
b5a54d9a31
commit
34db548bfb
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@ -50,10 +50,9 @@
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#include "mlx4_en.h"
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static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_alloc *page_alloc,
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const struct mlx4_en_frag_info *frag_info,
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gfp_t gfp)
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static int mlx4_alloc_page(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_alloc *frag,
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gfp_t gfp)
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{
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struct page *page;
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dma_addr_t dma;
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@ -63,145 +62,46 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
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return -ENOMEM;
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dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE, priv->dma_dir);
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if (unlikely(dma_mapping_error(priv->ddev, dma))) {
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put_page(page);
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__free_page(page);
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return -ENOMEM;
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}
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page_alloc->page = page;
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page_alloc->dma = dma;
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page_alloc->page_offset = 0;
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/* Not doing get_page() for each frag is a big win
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* on asymetric workloads. Note we can not use atomic_set().
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*/
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page_ref_add(page, PAGE_SIZE / frag_info->frag_stride - 1);
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frag->page = page;
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frag->dma = dma;
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frag->page_offset = priv->rx_headroom;
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return 0;
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}
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static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_desc *rx_desc,
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struct mlx4_en_rx_alloc *frags,
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struct mlx4_en_rx_alloc *ring_alloc,
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gfp_t gfp)
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{
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struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
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const struct mlx4_en_frag_info *frag_info;
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struct page *page;
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int i;
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for (i = 0; i < priv->num_frags; i++) {
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frag_info = &priv->frag_info[i];
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page_alloc[i] = ring_alloc[i];
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page_alloc[i].page_offset += frag_info->frag_stride;
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if (page_alloc[i].page_offset + frag_info->frag_stride <=
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PAGE_SIZE)
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continue;
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if (unlikely(mlx4_alloc_pages(priv, &page_alloc[i],
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frag_info, gfp)))
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goto out;
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}
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for (i = 0; i < priv->num_frags; i++) {
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frags[i] = ring_alloc[i];
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frags[i].page_offset += priv->rx_headroom;
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rx_desc->data[i].addr = cpu_to_be64(frags[i].dma +
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frags[i].page_offset);
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ring_alloc[i] = page_alloc[i];
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}
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return 0;
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out:
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while (i--) {
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if (page_alloc[i].page != ring_alloc[i].page) {
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dma_unmap_page(priv->ddev, page_alloc[i].dma,
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PAGE_SIZE, priv->dma_dir);
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page = page_alloc[i].page;
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/* Revert changes done by mlx4_alloc_pages */
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page_ref_sub(page, PAGE_SIZE /
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priv->frag_info[i].frag_stride - 1);
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put_page(page);
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}
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}
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return -ENOMEM;
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}
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static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_alloc *frags,
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int i)
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{
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const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
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u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;
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if (next_frag_end > PAGE_SIZE)
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dma_unmap_page(priv->ddev, frags[i].dma, PAGE_SIZE,
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priv->dma_dir);
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if (frags[i].page)
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put_page(frags[i].page);
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}
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static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_ring *ring)
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{
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int i;
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struct mlx4_en_rx_alloc *page_alloc;
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for (i = 0; i < priv->num_frags; i++) {
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const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
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if (mlx4_alloc_pages(priv, &ring->page_alloc[i],
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frag_info, GFP_KERNEL | __GFP_COLD))
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goto out;
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en_dbg(DRV, priv, " frag %d allocator: - frags:%d\n",
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i, page_ref_count(ring->page_alloc[i].page));
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for (i = 0; i < priv->num_frags; i++, frags++) {
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if (!frags->page && mlx4_alloc_page(priv, frags, gfp))
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return -ENOMEM;
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rx_desc->data[i].addr = cpu_to_be64(frags->dma +
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frags->page_offset);
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}
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return 0;
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out:
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while (i--) {
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struct page *page;
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page_alloc = &ring->page_alloc[i];
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dma_unmap_page(priv->ddev, page_alloc->dma,
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PAGE_SIZE, priv->dma_dir);
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page = page_alloc->page;
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/* Revert changes done by mlx4_alloc_pages */
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page_ref_sub(page, PAGE_SIZE /
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priv->frag_info[i].frag_stride - 1);
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put_page(page);
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page_alloc->page = NULL;
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}
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return -ENOMEM;
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}
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static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_ring *ring)
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static void mlx4_en_free_frag(const struct mlx4_en_priv *priv,
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struct mlx4_en_rx_alloc *frag)
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{
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struct mlx4_en_rx_alloc *page_alloc;
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int i;
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for (i = 0; i < priv->num_frags; i++) {
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const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
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page_alloc = &ring->page_alloc[i];
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en_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
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i, page_count(page_alloc->page));
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dma_unmap_page(priv->ddev, page_alloc->dma,
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if (frag->page) {
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dma_unmap_page(priv->ddev, frag->dma,
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PAGE_SIZE, priv->dma_dir);
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while (page_alloc->page_offset + frag_info->frag_stride <
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PAGE_SIZE) {
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put_page(page_alloc->page);
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page_alloc->page_offset += frag_info->frag_stride;
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}
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page_alloc->page = NULL;
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__free_page(frag->page);
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}
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/* We need to clear all fields, otherwise a change of priv->log_rx_info
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* could lead to see garbage later in frag->page.
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*/
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memset(frag, 0, sizeof(*frag));
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}
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static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
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static void mlx4_en_init_rx_desc(const struct mlx4_en_priv *priv,
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struct mlx4_en_rx_ring *ring, int index)
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{
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struct mlx4_en_rx_desc *rx_desc = ring->buf + ring->stride * index;
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@ -235,19 +135,22 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
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(index << priv->log_rx_info);
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if (ring->page_cache.index > 0) {
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ring->page_cache.index--;
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frags[0].page = ring->page_cache.buf[ring->page_cache.index].page;
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frags[0].dma = ring->page_cache.buf[ring->page_cache.index].dma;
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frags[0].page_offset = XDP_PACKET_HEADROOM;
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rx_desc->data[0].addr = cpu_to_be64(frags[0].dma +
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frags[0].page_offset);
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/* XDP uses a single page per frame */
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if (!frags->page) {
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ring->page_cache.index--;
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frags->page = ring->page_cache.buf[ring->page_cache.index].page;
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frags->dma = ring->page_cache.buf[ring->page_cache.index].dma;
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}
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frags->page_offset = XDP_PACKET_HEADROOM;
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rx_desc->data[0].addr = cpu_to_be64(frags->dma +
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XDP_PACKET_HEADROOM);
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return 0;
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}
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return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc, gfp);
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return mlx4_en_alloc_frags(priv, rx_desc, frags, gfp);
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}
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static inline bool mlx4_en_is_ring_empty(struct mlx4_en_rx_ring *ring)
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static bool mlx4_en_is_ring_empty(const struct mlx4_en_rx_ring *ring)
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{
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return ring->prod == ring->cons;
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}
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@ -257,7 +160,8 @@ static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
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*ring->wqres.db.db = cpu_to_be32(ring->prod & 0xffff);
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}
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static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
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/* slow path */
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static void mlx4_en_free_rx_desc(const struct mlx4_en_priv *priv,
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struct mlx4_en_rx_ring *ring,
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int index)
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{
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@ -267,7 +171,7 @@ static void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
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frags = ring->rx_info + (index << priv->log_rx_info);
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for (nr = 0; nr < priv->num_frags; nr++) {
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en_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
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mlx4_en_free_frag(priv, frags, nr);
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mlx4_en_free_frag(priv, frags + nr);
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}
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}
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@ -323,12 +227,12 @@ static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
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ring->cons, ring->prod);
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/* Unmap and free Rx buffers */
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while (!mlx4_en_is_ring_empty(ring)) {
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index = ring->cons & ring->size_mask;
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for (index = 0; index < ring->size; index++) {
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en_dbg(DRV, priv, "Processing descriptor:%d\n", index);
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mlx4_en_free_rx_desc(priv, ring, index);
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++ring->cons;
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}
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ring->cons = 0;
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ring->prod = 0;
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}
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void mlx4_en_set_num_rx_rings(struct mlx4_en_dev *mdev)
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@ -380,9 +284,9 @@ int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
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tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
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sizeof(struct mlx4_en_rx_alloc));
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ring->rx_info = vmalloc_node(tmp, node);
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ring->rx_info = vzalloc_node(tmp, node);
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if (!ring->rx_info) {
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ring->rx_info = vmalloc(tmp);
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ring->rx_info = vzalloc(tmp);
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if (!ring->rx_info) {
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err = -ENOMEM;
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goto err_ring;
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@ -452,16 +356,6 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
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/* Initialize all descriptors */
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for (i = 0; i < ring->size; i++)
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mlx4_en_init_rx_desc(priv, ring, i);
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/* Initialize page allocators */
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err = mlx4_en_init_allocator(priv, ring);
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if (err) {
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en_err(priv, "Failed initializing ring allocator\n");
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if (ring->stride <= TXBB_SIZE)
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ring->buf -= TXBB_SIZE;
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ring_ind--;
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goto err_allocator;
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}
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}
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err = mlx4_en_fill_rx_buffers(priv);
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if (err)
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@ -481,11 +375,9 @@ int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
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mlx4_en_free_rx_buf(priv, priv->rx_ring[ring_ind]);
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ring_ind = priv->rx_ring_num - 1;
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err_allocator:
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while (ring_ind >= 0) {
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if (priv->rx_ring[ring_ind]->stride <= TXBB_SIZE)
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priv->rx_ring[ring_ind]->buf -= TXBB_SIZE;
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mlx4_en_destroy_allocator(priv, priv->rx_ring[ring_ind]);
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ring_ind--;
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}
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return err;
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@ -565,50 +457,68 @@ void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
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mlx4_en_free_rx_buf(priv, ring);
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if (ring->stride <= TXBB_SIZE)
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ring->buf -= TXBB_SIZE;
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mlx4_en_destroy_allocator(priv, ring);
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}
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static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
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struct mlx4_en_rx_desc *rx_desc,
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struct mlx4_en_rx_alloc *frags,
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struct sk_buff *skb,
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int length)
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{
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struct skb_frag_struct *skb_frags_rx = skb_shinfo(skb)->frags;
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struct mlx4_en_frag_info *frag_info = priv->frag_info;
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const struct mlx4_en_frag_info *frag_info = priv->frag_info;
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unsigned int truesize = 0;
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int nr, frag_size;
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struct page *page;
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dma_addr_t dma;
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bool release;
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/* Collect used fragments while replacing them in the HW descriptors */
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for (nr = 0;;) {
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for (nr = 0;; frags++) {
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frag_size = min_t(int, length, frag_info->frag_size);
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if (unlikely(!frags[nr].page))
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page = frags->page;
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if (unlikely(!page))
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goto fail;
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dma = be64_to_cpu(rx_desc->data[nr].addr);
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dma_sync_single_for_cpu(priv->ddev, dma, frag_info->frag_size,
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DMA_FROM_DEVICE);
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dma = frags->dma;
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dma_sync_single_range_for_cpu(priv->ddev, dma, frags->page_offset,
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frag_size, priv->dma_dir);
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__skb_fill_page_desc(skb, nr, frags[nr].page,
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frags[nr].page_offset,
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__skb_fill_page_desc(skb, nr, page, frags->page_offset,
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frag_size);
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skb->truesize += frag_info->frag_stride;
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frags[nr].page = NULL;
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truesize += frag_info->frag_stride;
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if (frag_info->frag_stride == PAGE_SIZE / 2) {
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frags->page_offset ^= PAGE_SIZE / 2;
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release = page_count(page) != 1 ||
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page_is_pfmemalloc(page) ||
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page_to_nid(page) != numa_mem_id();
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} else {
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u32 sz_align = ALIGN(frag_size, SMP_CACHE_BYTES);
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frags->page_offset += sz_align;
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release = frags->page_offset + frag_info->frag_size > PAGE_SIZE;
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}
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if (release) {
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dma_unmap_page(priv->ddev, dma, PAGE_SIZE, priv->dma_dir);
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frags->page = NULL;
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} else {
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page_ref_inc(page);
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}
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nr++;
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length -= frag_size;
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if (!length)
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break;
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frag_info++;
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}
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skb->truesize += truesize;
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return nr;
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fail:
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while (nr > 0) {
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nr--;
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__skb_frag_unref(&skb_frags_rx[nr]);
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__skb_frag_unref(skb_shinfo(skb)->frags + nr);
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}
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return 0;
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}
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@ -639,7 +549,8 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
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if (length <= SMALL_PACKET_SIZE) {
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/* We are copying all relevant data to the skb - temporarily
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* sync buffers for the copy */
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dma = be64_to_cpu(rx_desc->data[0].addr);
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dma = frags[0].dma + frags[0].page_offset;
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dma_sync_single_for_cpu(priv->ddev, dma, length,
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DMA_FROM_DEVICE);
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skb_copy_to_linear_data(skb, va, length);
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@ -648,7 +559,7 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
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unsigned int pull_len;
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/* Move relevant fragments to skb */
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used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, frags,
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used_frags = mlx4_en_complete_rx_desc(priv, frags,
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skb, length);
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if (unlikely(!used_frags)) {
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kfree_skb(skb);
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@ -916,8 +827,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
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case XDP_TX:
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if (likely(!mlx4_en_xmit_frame(ring, frags, dev,
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length, cq->ring,
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&doorbell_pending)))
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goto consumed;
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&doorbell_pending))) {
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frags[0].page = NULL;
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goto next;
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}
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trace_xdp_exception(dev, xdp_prog, act);
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goto xdp_drop_no_cnt; /* Drop on xmit failure */
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default:
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|
|
@ -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;
|
||||
|
|
|
|||
|
|
@ -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;
|
||||
|
|
|
|||
Loading…
Reference in New Issue