From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDEDEE555 for ; Thu, 16 Jan 2025 02:05:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736993161; cv=none; b=BQQCjdrvsz2j8Dn5hQ4upp4JGMnsbprLIOiJUaToITaxJNbntx5SB8hqGbJAM30j6j6pB0UiGd7ONeDQIA1aIboPlG6R+rmdQ8yriTJzJ2u9MdS9rjEwnPd1Kr2sMm8GNk/YY+AzIUVm3ixzR7ODnRNG3MOXjMCWiozzAWlbyqE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736993161; c=relaxed/simple; bh=XyfRDqb0/XnepzUeZ5FU7SrNyZCtV4uRhhXZSL6CR1s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fV7pT/aQjPwBrW3yvOUBiLZ1C+dtIa4o9d81EDdgYch3ieDPslYLs35Nk7ayMr4/uKcBM/JSJnPDlfDld5lpBBJOCAKisvcOrd5wqNXzu+tPmB+qf4HjOUJzQpLE3GnQHGIu2oC+GOUN+RxX6VaVsFynHTdyz4auDQRuc3uKULA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=qGv0IY4Q; arc=none smtp.client-ip=95.215.58.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="qGv0IY4Q" Message-ID: <1985a09f-f851-48a6-af6c-07e21611b514@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1736993145; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RVbG7W6+7JxHys/x2BFctt4lICVhXoK01DPy3Q0JzFo=; b=qGv0IY4QgXb/DWaMfG35Kdr+HZFobNX/I/1i5oqx198Wbz3zSDY5uEXo0sUhoLT9RilHH8 XqWtLE/8gjiG5MLgHztvVngAnwzdOEzWd3NXb8a0eG/GYfuJm4TT8I2rkDca09TK9bUMWe 1dJKtkimFLnDZwhBrtUjOO9tfs51iEI= Date: Thu, 16 Jan 2025 10:05:37 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net-next v3 1/4] net: stmmac: Switch to zero-copy in non-XDP RX path To: Furong Xu <0x1207@gmail.com>, netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alexander Lobakin , Joe Damato , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , xfr@outlook.com References: Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yanteng Si In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2025/1/15 11:27, Furong Xu 写道: > Avoid memcpy in non-XDP RX path by marking all allocated SKBs to > be recycled in the upper network stack. > > This patch brings ~11.5% driver performance improvement in a TCP RX > throughput test with iPerf tool on a single isolated Cortex-A65 CPU > core, from 2.18 Gbits/sec increased to 2.43 Gbits/sec. > > Signed-off-by: Furong Xu <0x1207@gmail.com> > Reviewed-by: Alexander Lobakin Reviewed-by: Yanteng Si Thanks, Yanteng > --- > drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 + > .../net/ethernet/stmicro/stmmac/stmmac_main.c | 26 ++++++++++++------- > 2 files changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h > index e8dbce20129c..f05cae103d83 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h > @@ -126,6 +126,7 @@ struct stmmac_rx_queue { > unsigned int cur_rx; > unsigned int dirty_rx; > unsigned int buf_alloc_num; > + unsigned int napi_skb_frag_size; > dma_addr_t dma_rx_phy; > u32 rx_tail_addr; > unsigned int state_saved; > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index acd6994c1764..1d98a5e8c98c 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -1341,7 +1341,7 @@ static unsigned int stmmac_rx_offset(struct stmmac_priv *priv) > if (stmmac_xdp_is_enabled(priv)) > return XDP_PACKET_HEADROOM; > > - return 0; > + return NET_SKB_PAD; > } > > static int stmmac_set_bfsize(int mtu, int bufsize) > @@ -2040,17 +2040,21 @@ static int __alloc_dma_rx_desc_resources(struct stmmac_priv *priv, > struct stmmac_channel *ch = &priv->channel[queue]; > bool xdp_prog = stmmac_xdp_is_enabled(priv); > struct page_pool_params pp_params = { 0 }; > - unsigned int num_pages; > + unsigned int dma_buf_sz_pad, num_pages; > unsigned int napi_id; > int ret; > > + dma_buf_sz_pad = stmmac_rx_offset(priv) + dma_conf->dma_buf_sz + > + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > + num_pages = DIV_ROUND_UP(dma_buf_sz_pad, PAGE_SIZE); > + > rx_q->queue_index = queue; > rx_q->priv_data = priv; > + rx_q->napi_skb_frag_size = num_pages * PAGE_SIZE; > > pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV; > pp_params.pool_size = dma_conf->dma_rx_size; > - num_pages = DIV_ROUND_UP(dma_conf->dma_buf_sz, PAGE_SIZE); > - pp_params.order = ilog2(num_pages); > + pp_params.order = order_base_2(num_pages); > pp_params.nid = dev_to_node(priv->device); > pp_params.dev = priv->device; > pp_params.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE; > @@ -5582,22 +5586,26 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) > } > > if (!skb) { > + unsigned int head_pad_len; > + > /* XDP program may expand or reduce tail */ > buf1_len = ctx.xdp.data_end - ctx.xdp.data; > > - skb = napi_alloc_skb(&ch->rx_napi, buf1_len); > + skb = napi_build_skb(page_address(buf->page), > + rx_q->napi_skb_frag_size); > if (!skb) { > + page_pool_recycle_direct(rx_q->page_pool, > + buf->page); > rx_dropped++; > count++; > goto drain_data; > } > > /* XDP program may adjust header */ > - skb_copy_to_linear_data(skb, ctx.xdp.data, buf1_len); > + head_pad_len = ctx.xdp.data - ctx.xdp.data_hard_start; > + skb_reserve(skb, head_pad_len); > skb_put(skb, buf1_len); > - > - /* Data payload copied into SKB, page ready for recycle */ > - page_pool_recycle_direct(rx_q->page_pool, buf->page); > + skb_mark_for_recycle(skb); > buf->page = NULL; > } else if (buf1_len) { > dma_sync_single_for_cpu(priv->device, buf->addr,