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Date:   Fri, 30 Sep 2022 21:52:02 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Shenwei Wang <shenwei.wang@nxp.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Wei Fang <wei.fang@nxp.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, imx@lists.linux.dev
Subject: Re: [PATCH 1/1] net: fec: using page pool to manage RX buffers
Message-ID: <YzdI4mDXCKuI/58N@lunn.ch>
References: <20220930193751.1249054-1-shenwei.wang@nxp.com>
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On Fri, Sep 30, 2022 at 02:37:51PM -0500, Shenwei Wang wrote:
> This patch optimizes the RX buffer management by using the page
> pool. The purpose for this change is to prepare for the following
> XDP support. The current driver uses one frame per page for easy
> management.
> 
> The following are the comparing result between page pool implementation
> and the original implementation (non page pool).
> 
>  --- Page Pool implementation ----
> 
> shenwei@5810:~$ iperf -c 10.81.16.245 -w 2m -i 1
> ------------------------------------------------------------
> Client connecting to 10.81.16.245, TCP port 5001
> TCP window size:  416 KByte (WARNING: requested 1.91 MByte)
> ------------------------------------------------------------
> [  1] local 10.81.17.20 port 43204 connected with 10.81.16.245 port 5001
> [ ID] Interval       Transfer     Bandwidth
> [  1] 0.0000-1.0000 sec   111 MBytes   933 Mbits/sec
> [  1] 1.0000-2.0000 sec   111 MBytes   934 Mbits/sec
> [  1] 2.0000-3.0000 sec   112 MBytes   935 Mbits/sec
> [  1] 3.0000-4.0000 sec   111 MBytes   933 Mbits/sec
> [  1] 4.0000-5.0000 sec   111 MBytes   934 Mbits/sec
> [  1] 5.0000-6.0000 sec   111 MBytes   933 Mbits/sec
> [  1] 6.0000-7.0000 sec   111 MBytes   931 Mbits/sec
> [  1] 7.0000-8.0000 sec   112 MBytes   935 Mbits/sec
> [  1] 8.0000-9.0000 sec   111 MBytes   933 Mbits/sec
> [  1] 9.0000-10.0000 sec   112 MBytes   935 Mbits/sec
> [  1] 0.0000-10.0077 sec  1.09 GBytes   933 Mbits/sec
> 
>  --- Non Page Pool implementation ----
> 
> shenwei@5810:~$ iperf -c 10.81.16.245 -w 2m -i 1
> ------------------------------------------------------------
> Client connecting to 10.81.16.245, TCP port 5001
> TCP window size:  416 KByte (WARNING: requested 1.91 MByte)
> ------------------------------------------------------------
> [  1] local 10.81.17.20 port 49154 connected with 10.81.16.245 port 5001
> [ ID] Interval       Transfer     Bandwidth
> [  1] 0.0000-1.0000 sec   104 MBytes   868 Mbits/sec
> [  1] 1.0000-2.0000 sec   105 MBytes   878 Mbits/sec
> [  1] 2.0000-3.0000 sec   105 MBytes   881 Mbits/sec
> [  1] 3.0000-4.0000 sec   105 MBytes   879 Mbits/sec
> [  1] 4.0000-5.0000 sec   105 MBytes   878 Mbits/sec
> [  1] 5.0000-6.0000 sec   105 MBytes   878 Mbits/sec
> [  1] 6.0000-7.0000 sec   104 MBytes   875 Mbits/sec
> [  1] 7.0000-8.0000 sec   104 MBytes   875 Mbits/sec
> [  1] 8.0000-9.0000 sec   104 MBytes   873 Mbits/sec
> [  1] 9.0000-10.0000 sec   104 MBytes   875 Mbits/sec
> [  1] 0.0000-10.0073 sec  1.02 GBytes   875 Mbits/sec

What SoC? As i keep saying, the FEC is used in a lot of different
SoCs, and you need to show this does not cause any regressions in the
older SoCs. There are probably a lot more imx5 and imx6 devices out in
the wild than imx8, which is what i guess you are testing on. Mainline
needs to work well on them all, even if NXP no longer cares about the
older Socs.

    Andrew