github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 10:09:10 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

Merge branch 'net-mlx5-avoid-payload-in-skb-s-linear-part-for-better-gro-processing'

Browse Source 
Tariq Toukan says:

====================
net/mlx5: Avoid payload in skb's linear part for better GRO-processing

This is V7 of a series originally submitted by Christoph.

When LRO is enabled on the MLX, mlx5e_skb_from_cqe_mpwrq_nonlinear
copies parts of the payload to the linear part of the skb.

This triggers suboptimal processing in GRO, causing slow throughput.

This patch series addresses this by using eth_get_headlen to compute the
size of the protocol headers and only copy those bits. This results in a
significant throughput improvement (detailed results in the specific
patch).
====================

Link: https://patch.msgid.link/20260601061522.398044-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2026-06-02 14:12:36 -07:00
commit b736e34b96
1 changed files with 22 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
View File

@ -1912,7 +1912,6 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
u32 page_idx)
{
struct mlx5e_frag_page *frag_page = &wi->alloc_units.frag_pages[page_idx];
u16 headlen = min_t(u16, MLX5E_RX_MAX_HEAD, cqe_bcnt);
struct mlx5e_frag_page *head_page = frag_page;
struct mlx5e_frag_page *linear_page = NULL;
struct mlx5e_xdp_buff *mxbuf = &rq->mxbuf;
@ -1923,11 +1922,12 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
unsigned int truesize = 0;
u32 pg_consumed_bytes;
struct bpf_prog *prog;
void *va, *head_addr;
struct sk_buff *skb;
u32 linear_frame_sz;
u16 linear_data_len;
u16 linear_hr;
void *va;
u16 headlen;
if (unlikely(cqe_bcnt > rq->hw_mtu)) {
u8 lro_num_seg = get_cqe_lro_num_seg(cqe);
@ -1940,9 +1940,11 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
prog = rcu_dereference(rq->xdp_prog);
head_addr = netmem_address(head_page->netmem) + head_offset;
if (prog) {
/* area for bpf_xdp_[store|load]_bytes */
net_prefetchw(netmem_address(frag_page->netmem) + frag_offset);
net_prefetchw(head_addr);
va = mlx5e_mpwqe_get_linear_page_frag(rq);
if (!va) {
@ -1956,6 +1958,8 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
linear_frame_sz = MLX5_SKB_FRAG_SZ(linear_hr + MLX5E_RX_MAX_HEAD);
linear_page = &rq->mpwqe.linear_info->frag_page;
} else {
dma_addr_t addr;
skb = napi_alloc_skb(rq->cq.napi,
ALIGN(MLX5E_RX_MAX_HEAD, sizeof(long)));
if (unlikely(!skb)) {
@ -1967,6 +1971,14 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
net_prefetchw(va); /* xdp_frame data area */
net_prefetchw(skb->data);
headlen = min(MLX5E_RX_MAX_HEAD, cqe_bcnt);
addr = page_pool_get_dma_addr_netmem(head_page->netmem);
dma_sync_single_for_cpu(rq->pdev, addr + head_offset,
ALIGN(headlen, sizeof(long)),
rq->buff.map_dir);
headlen = eth_get_headlen(rq->netdev, head_addr, headlen);
frag_offset += headlen;
byte_cnt -= headlen;
linear_hr = skb_headroom(skb);
@ -2051,13 +2063,11 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
pagep->frags++;
while (++pagep < frag_page);
headlen = min_t(u16, MLX5E_RX_MAX_HEAD - len,
skb->data_len);
__pskb_pull_tail(skb, headlen);
if (len < ETH_HLEN)
__pskb_pull_tail(skb, min(ETH_HLEN - len,
skb->data_len));
}
} else {
dma_addr_t addr;
if (xdp_buff_has_frags(&mxbuf->xdp)) {
struct mlx5e_frag_page *pagep;
@ -2071,10 +2081,11 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
pagep->frags++;
while (++pagep < frag_page);
}
/* copy header */
addr = page_pool_get_dma_addr_netmem(head_page->netmem);
mlx5e_copy_skb_header(rq, skb, head_page->netmem, addr,
head_offset, head_offset, headlen);
skb_copy_to_linear_data(skb, head_addr,
ALIGN(headlen, sizeof(long)));
/* skb linear part was allocated with headlen and aligned to long */
skb->tail += headlen;
skb->len += headlen;