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

[Shengyu Qu]

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 at 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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