forked from Minki/linux
mlx4: allow order-0 memory allocations in RX path
Signed-off-by: Eric Dumazet <edumazet@google.com> mlx4 exclusively uses order-2 allocations in RX path, which are likely to fail under memory pressure. We therefore drop frames more than needed. This patch tries order-3, order-2, order-1 and finally order-0 allocations to keep good performance, yet allow allocations if/when memory gets fragmented. By using larger pages, and avoiding unnecessary get_page()/put_page() on compound pages, this patch improves performance as well, lowering false sharing on struct page. Also use GFP_KERNEL allocations in initialization path, as allocating 12 MB (390 order-3 pages) can easily fail with GFP_ATOMIC. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Amir Vadai <amirv@mellanox.com> Acked-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
David S. Miller
parent
3bae9db9aa
commit
51151a16a6
@ -43,40 +43,64 @@
|
||||
|
||||
#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)
|
||||
{
|
||||
int order;
|
||||
struct page *page;
|
||||
dma_addr_t dma;
|
||||
|
||||
for (order = MLX4_EN_ALLOC_PREFER_ORDER; ;) {
|
||||
gfp_t gfp = _gfp;
|
||||
|
||||
if (order)
|
||||
gfp |= __GFP_COMP | __GFP_NOWARN;
|
||||
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,
|
||||
PCI_DMA_FROMDEVICE);
|
||||
if (dma_mapping_error(priv->ddev, dma)) {
|
||||
put_page(page);
|
||||
return -ENOMEM;
|
||||
}
|
||||
page_alloc->size = PAGE_SIZE << order;
|
||||
page_alloc->page = page;
|
||||
page_alloc->dma = dma;
|
||||
page_alloc->offset = frag_info->frag_align;
|
||||
/* Not doing get_page() for each frag is a big win
|
||||
* on asymetric workloads.
|
||||
*/
|
||||
atomic_set(&page->_count, page_alloc->size / frag_info->frag_stride);
|
||||
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)
|
||||
struct mlx4_en_rx_alloc *ring_alloc,
|
||||
gfp_t gfp)
|
||||
{
|
||||
struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
|
||||
struct mlx4_en_frag_info *frag_info;
|
||||
const struct mlx4_en_frag_info *frag_info;
|
||||
struct page *page;
|
||||
dma_addr_t dma;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < priv->num_frags; i++) {
|
||||
frag_info = &priv->frag_info[i];
|
||||
if (ring_alloc[i].offset == frag_info->last_offset) {
|
||||
page = alloc_pages(GFP_ATOMIC | __GFP_COMP,
|
||||
MLX4_EN_ALLOC_ORDER);
|
||||
if (!page)
|
||||
page_alloc[i] = ring_alloc[i];
|
||||
page_alloc[i].offset += frag_info->frag_stride;
|
||||
if (page_alloc[i].offset + frag_info->frag_stride <= ring_alloc[i].size)
|
||||
continue;
|
||||
if (mlx4_alloc_pages(priv, &page_alloc[i], frag_info, gfp))
|
||||
goto out;
|
||||
dma = dma_map_page(priv->ddev, page, 0,
|
||||
MLX4_EN_ALLOC_SIZE, PCI_DMA_FROMDEVICE);
|
||||
if (dma_mapping_error(priv->ddev, dma)) {
|
||||
put_page(page);
|
||||
goto out;
|
||||
}
|
||||
page_alloc[i].page = page;
|
||||
page_alloc[i].dma = dma;
|
||||
page_alloc[i].offset = frag_info->frag_align;
|
||||
} else {
|
||||
page_alloc[i].page = ring_alloc[i].page;
|
||||
get_page(ring_alloc[i].page);
|
||||
page_alloc[i].dma = ring_alloc[i].dma;
|
||||
page_alloc[i].offset = ring_alloc[i].offset +
|
||||
frag_info->frag_stride;
|
||||
}
|
||||
}
|
||||
|
||||
for (i = 0; i < priv->num_frags; i++) {
|
||||
@ -88,14 +112,16 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
|
||||
|
||||
return 0;
|
||||
|
||||
|
||||
out:
|
||||
while (i--) {
|
||||
frag_info = &priv->frag_info[i];
|
||||
if (ring_alloc[i].offset == frag_info->last_offset)
|
||||
if (page_alloc[i].page != ring_alloc[i].page) {
|
||||
dma_unmap_page(priv->ddev, page_alloc[i].dma,
|
||||
MLX4_EN_ALLOC_SIZE, PCI_DMA_FROMDEVICE);
|
||||
put_page(page_alloc[i].page);
|
||||
page_alloc[i].size, PCI_DMA_FROMDEVICE);
|
||||
page = page_alloc[i].page;
|
||||
atomic_set(&page->_count, 1);
|
||||
put_page(page);
|
||||
}
|
||||
}
|
||||
return -ENOMEM;
|
||||
}
|
||||
@ -104,12 +130,12 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
|
||||
struct mlx4_en_rx_alloc *frags,
|
||||
int i)
|
||||
{
|
||||
struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
|
||||
const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
|
||||
|
||||
if (frags[i].offset == frag_info->last_offset) {
|
||||
dma_unmap_page(priv->ddev, frags[i].dma, MLX4_EN_ALLOC_SIZE,
|
||||
if (frags[i].offset + frag_info->frag_stride > frags[i].size)
|
||||
dma_unmap_page(priv->ddev, frags[i].dma, frags[i].size,
|
||||
PCI_DMA_FROMDEVICE);
|
||||
}
|
||||
|
||||
if (frags[i].page)
|
||||
put_page(frags[i].page);
|
||||
}
|
||||
@ -117,35 +143,28 @@ static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
|
||||
static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
|
||||
struct mlx4_en_rx_ring *ring)
|
||||
{
|
||||
struct mlx4_en_rx_alloc *page_alloc;
|
||||
int i;
|
||||
struct mlx4_en_rx_alloc *page_alloc;
|
||||
|
||||
for (i = 0; i < priv->num_frags; i++) {
|
||||
page_alloc = &ring->page_alloc[i];
|
||||
page_alloc->page = alloc_pages(GFP_ATOMIC | __GFP_COMP,
|
||||
MLX4_EN_ALLOC_ORDER);
|
||||
if (!page_alloc->page)
|
||||
goto out;
|
||||
const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
|
||||
|
||||
page_alloc->dma = dma_map_page(priv->ddev, page_alloc->page, 0,
|
||||
MLX4_EN_ALLOC_SIZE, PCI_DMA_FROMDEVICE);
|
||||
if (dma_mapping_error(priv->ddev, page_alloc->dma)) {
|
||||
put_page(page_alloc->page);
|
||||
page_alloc->page = NULL;
|
||||
if (mlx4_alloc_pages(priv, &ring->page_alloc[i],
|
||||
frag_info, GFP_KERNEL))
|
||||
goto out;
|
||||
}
|
||||
page_alloc->offset = priv->frag_info[i].frag_align;
|
||||
en_dbg(DRV, priv, "Initialized allocator:%d with page:%p\n",
|
||||
i, page_alloc->page);
|
||||
}
|
||||
return 0;
|
||||
|
||||
out:
|
||||
while (i--) {
|
||||
struct page *page;
|
||||
|
||||
page_alloc = &ring->page_alloc[i];
|
||||
dma_unmap_page(priv->ddev, page_alloc->dma,
|
||||
MLX4_EN_ALLOC_SIZE, PCI_DMA_FROMDEVICE);
|
||||
put_page(page_alloc->page);
|
||||
page_alloc->size, PCI_DMA_FROMDEVICE);
|
||||
page = page_alloc->page;
|
||||
atomic_set(&page->_count, 1);
|
||||
put_page(page);
|
||||
page_alloc->page = NULL;
|
||||
}
|
||||
return -ENOMEM;
|
||||
@ -158,13 +177,18 @@ static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
|
||||
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,
|
||||
MLX4_EN_ALLOC_SIZE, PCI_DMA_FROMDEVICE);
|
||||
page_alloc->size, PCI_DMA_FROMDEVICE);
|
||||
while (page_alloc->offset + frag_info->frag_stride < page_alloc->size) {
|
||||
put_page(page_alloc->page);
|
||||
page_alloc->offset += frag_info->frag_stride;
|
||||
}
|
||||
page_alloc->page = NULL;
|
||||
}
|
||||
}
|
||||
@ -195,13 +219,14 @@ static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
|
||||
}
|
||||
|
||||
static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
|
||||
struct mlx4_en_rx_ring *ring, int index)
|
||||
struct mlx4_en_rx_ring *ring, int index,
|
||||
gfp_t gfp)
|
||||
{
|
||||
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);
|
||||
|
||||
return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc);
|
||||
return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc, gfp);
|
||||
}
|
||||
|
||||
static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
|
||||
@ -235,7 +260,8 @@ static int mlx4_en_fill_rx_buffers(struct mlx4_en_priv *priv)
|
||||
ring = &priv->rx_ring[ring_ind];
|
||||
|
||||
if (mlx4_en_prepare_rx_desc(priv, ring,
|
||||
ring->actual_size)) {
|
||||
ring->actual_size,
|
||||
GFP_KERNEL)) {
|
||||
if (ring->actual_size < MLX4_EN_MIN_RX_SIZE) {
|
||||
en_err(priv, "Failed to allocate "
|
||||
"enough rx buffers\n");
|
||||
@ -450,11 +476,11 @@ static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
|
||||
DMA_FROM_DEVICE);
|
||||
|
||||
/* Save page reference in skb */
|
||||
get_page(frags[nr].page);
|
||||
__skb_frag_set_page(&skb_frags_rx[nr], frags[nr].page);
|
||||
skb_frag_size_set(&skb_frags_rx[nr], frag_info->frag_size);
|
||||
skb_frags_rx[nr].page_offset = frags[nr].offset;
|
||||
skb->truesize += frag_info->frag_stride;
|
||||
frags[nr].page = NULL;
|
||||
}
|
||||
/* Adjust size of last fragment to match actual length */
|
||||
if (nr > 0)
|
||||
@ -547,7 +573,7 @@ static void mlx4_en_refill_rx_buffers(struct mlx4_en_priv *priv,
|
||||
int index = ring->prod & ring->size_mask;
|
||||
|
||||
while ((u32) (ring->prod - ring->cons) < ring->actual_size) {
|
||||
if (mlx4_en_prepare_rx_desc(priv, ring, index))
|
||||
if (mlx4_en_prepare_rx_desc(priv, ring, index, GFP_ATOMIC))
|
||||
break;
|
||||
ring->prod++;
|
||||
index = ring->prod & ring->size_mask;
|
||||
@ -805,21 +831,7 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
|
||||
return done;
|
||||
}
|
||||
|
||||
|
||||
/* Calculate the last offset position that accommodates a full fragment
|
||||
* (assuming fagment size = stride-align) */
|
||||
static int mlx4_en_last_alloc_offset(struct mlx4_en_priv *priv, u16 stride, u16 align)
|
||||
{
|
||||
u16 res = MLX4_EN_ALLOC_SIZE % stride;
|
||||
u16 offset = MLX4_EN_ALLOC_SIZE - stride - res + align;
|
||||
|
||||
en_dbg(DRV, priv, "Calculated last offset for stride:%d align:%d "
|
||||
"res:%d offset:%d\n", stride, align, res, offset);
|
||||
return offset;
|
||||
}
|
||||
|
||||
|
||||
static int frag_sizes[] = {
|
||||
static const int frag_sizes[] = {
|
||||
FRAG_SZ0,
|
||||
FRAG_SZ1,
|
||||
FRAG_SZ2,
|
||||
@ -847,9 +859,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
|
||||
priv->frag_info[i].frag_stride =
|
||||
ALIGN(frag_sizes[i], SMP_CACHE_BYTES);
|
||||
}
|
||||
priv->frag_info[i].last_offset = mlx4_en_last_alloc_offset(
|
||||
priv, priv->frag_info[i].frag_stride,
|
||||
priv->frag_info[i].frag_align);
|
||||
buf_size += priv->frag_info[i].frag_size;
|
||||
i++;
|
||||
}
|
||||
@ -861,13 +870,13 @@ void mlx4_en_calc_rx_buf(struct net_device *dev)
|
||||
en_dbg(DRV, priv, "Rx buffer scatter-list (effective-mtu:%d "
|
||||
"num_frags:%d):\n", eff_mtu, priv->num_frags);
|
||||
for (i = 0; i < priv->num_frags; i++) {
|
||||
en_dbg(DRV, priv, " frag:%d - size:%d prefix:%d align:%d "
|
||||
"stride:%d last_offset:%d\n", i,
|
||||
en_err(priv,
|
||||
" frag:%d - size:%d prefix:%d align:%d stride:%d\n",
|
||||
i,
|
||||
priv->frag_info[i].frag_size,
|
||||
priv->frag_info[i].frag_prefix_size,
|
||||
priv->frag_info[i].frag_align,
|
||||
priv->frag_info[i].frag_stride,
|
||||
priv->frag_info[i].last_offset);
|
||||
priv->frag_info[i].frag_stride);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
@ -96,7 +96,8 @@
|
||||
|
||||
/* Use the maximum between 16384 and a single page */
|
||||
#define MLX4_EN_ALLOC_SIZE PAGE_ALIGN(16384)
|
||||
#define MLX4_EN_ALLOC_ORDER get_order(MLX4_EN_ALLOC_SIZE)
|
||||
|
||||
#define MLX4_EN_ALLOC_PREFER_ORDER PAGE_ALLOC_COSTLY_ORDER
|
||||
|
||||
/* Receive fragment sizes; we use at most 3 fragments (for 9600 byte MTU
|
||||
* and 4K allocations) */
|
||||
@ -236,7 +237,8 @@ struct mlx4_en_tx_desc {
|
||||
struct mlx4_en_rx_alloc {
|
||||
struct page *page;
|
||||
dma_addr_t dma;
|
||||
u16 offset;
|
||||
u32 offset;
|
||||
u32 size;
|
||||
};
|
||||
|
||||
struct mlx4_en_tx_ring {
|
||||
@ -439,8 +441,6 @@ struct mlx4_en_frag_info {
|
||||
u16 frag_prefix_size;
|
||||
u16 frag_stride;
|
||||
u16 frag_align;
|
||||
u16 last_offset;
|
||||
|
||||
};
|
||||
|
||||
#ifdef CONFIG_MLX4_EN_DCB
|
||||
|
||||
Loading…
Reference in New Issue
Block a user