Re: [PATCH net-next v2 1/2] net: ethernet: mtk_eth_soc: use prefetch methods

Shengyu Qu
2025-01-06T14:28:55Z

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Hello,

Sorry to bother, but what happened to this patch? Is it given up or
something?

Best regards,
Shengyu

在 2024/7/30 2:29, Elad Yifee 写道:
> Utilize kernel prefetch methods for faster cache line access.
> This change boosts driver performance,
> allowing the CPU to handle about 5% more packets/sec.
>
> Signed-off-by: Elad Yifee <eladwf@gmail.com>
> ---
> Changes in v2:
> - use net_prefetchw as suggested by Joe Damato
> - add (NET_SKB_PAD + eth->ip_align) offset to prefetched data
> - use eth->ip_align instead of NET_IP_ALIGN as it could be 0,
> depending on the platform
> ---
> drivers/net/ethernet/mediatek/mtk_eth_soc.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index 16ca427cf4c3..4d0052dbe3f4 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -1963,6 +1963,7 @@ static u32 mtk_xdp_run(struct mtk_eth *eth, struct mtk_rx_ring *ring,
> if (!prog)
> goto out;
>
> + net_prefetchw(xdp->data_hard_start);
> act = bpf_prog_run_xdp(prog, xdp);
> switch (act) {
> case XDP_PASS:
> @@ -2038,6 +2039,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
>
> idx = NEXT_DESP_IDX(ring->calc_idx, ring->dma_size);
> rxd = ring->dma + idx * eth->soc->rx.desc_size;
> + prefetch(rxd);
> data = ring->data[idx];
>
> if (!mtk_rx_get_desc(eth, &trxd, rxd))
> @@ -2105,6 +2107,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> if (ret != XDP_PASS)
> goto skip_rx;
>
> + net_prefetch(xdp.data_meta);
> skb = build_skb(data, PAGE_SIZE);
> if (unlikely(!skb)) {
> page_pool_put_full_page(ring->page_pool,
> @@ -2113,6 +2116,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> goto skip_rx;
> }
>
> + net_prefetchw(skb->data);
> skb_reserve(skb, xdp.data - xdp.data_hard_start);
> skb_put(skb, xdp.data_end - xdp.data);
> skb_mark_for_recycle(skb);
> @@ -2143,6 +2147,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> dma_unmap_single(eth->dma_dev, ((u64)trxd.rxd1 | addr64),
> ring->buf_size, DMA_FROM_DEVICE);
>
> + net_prefetch(data + NET_SKB_PAD + eth->ip_align);
> skb = build_skb(data, ring->frag_size);
> if (unlikely(!skb)) {
> netdev->stats.rx_dropped++;
> @@ -2150,7 +2155,8 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> goto skip_rx;
> }
>
> - skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
> + net_prefetchw(skb->data);
> + skb_reserve(skb, NET_SKB_PAD + eth->ip_align);
> skb_put(skb, pktlen);
> }
>

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