From: Furong Xu <0x1207@gmail.com>
To: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: <netdev@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>, <xfr@outlook.com>
Subject: Re: [PATCH net-next v1 3/3] net: stmmac: Optimize cache prefetch in RX path
Date: Mon, 13 Jan 2025 20:37:10 +0800 [thread overview]
Message-ID: <20250113203710.000033dc@gmail.com> (raw)
In-Reply-To: <f20c339f-5286-477c-9255-e2e1fbeba57c@intel.com>
On Mon, 13 Jan 2025 13:10:46 +0100, Alexander Lobakin <aleksander.lobakin@intel.com> wrote:
> > @@ -5596,6 +5593,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
> > } else if (buf1_len) {
> > dma_sync_single_for_cpu(priv->device, buf->addr,
> > buf1_len, dma_dir);
> > + prefetch(page_address(buf->page) + buf->page_offset);
> > skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
> > buf->page, buf->page_offset, buf1_len,
> > priv->dma_conf.dma_buf_sz);
>
> Are you sure you need to prefetch frags as well? I'd say this is a waste
> of cycles, as the kernel core stack barely looks at payload...
> Probably prefetching only header buffers would be enough.
>
Yes, do not prefetch for frags is more reasonable.
Thanks!
pw-bot: changes-requested
prev parent reply other threads:[~2025-01-13 12:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-10 9:53 [PATCH net-next v1 0/3] net: stmmac: RX performance improvement Furong Xu
2025-01-10 9:53 ` [PATCH net-next v1 1/3] net: stmmac: Switch to zero-copy in non-XDP RX path Furong Xu
2025-01-13 9:41 ` Yanteng Si
2025-01-13 12:03 ` Alexander Lobakin
2025-01-13 15:16 ` Yanteng Si
2025-01-13 16:48 ` Andrew Lunn
2025-01-14 17:23 ` Alexander Lobakin
2025-01-10 9:53 ` [PATCH net-next v1 2/3] net: stmmac: Set page_pool_params.max_len to a precise size Furong Xu
2025-01-10 9:53 ` [PATCH net-next v1 3/3] net: stmmac: Optimize cache prefetch in RX path Furong Xu
2025-01-13 12:10 ` Alexander Lobakin
2025-01-13 12:37 ` Furong Xu [this message]
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