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From:   Magnus Karlsson <magnus.karlsson@gmail.com>
Date:   Fri, 27 Nov 2020 09:23:08 +0100
Message-ID: <CAJ8uoz2snP+nMMnDSZOMx2-xD9ZSfBCVuqvRZhoV5tRjR5r0Xg@mail.gmail.com>
Subject: Re: [PATCH bpf v2 1/2] xsk: replace datagram_poll by sock_poll_wait
To:     Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc:     =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@intel.com>,
        Magnus Karlsson <magnus.karlsson@intel.com>,
        Jonathan Lemon <jonathan.lemon@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        KP Singh <kpsingh@chromium.org>,
        "open list:XDP SOCKETS (AF_XDP)" <netdev@vger.kernel.org>,
        "open list:XDP SOCKETS (AF_XDP)" <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Wed, Nov 25, 2020 at 7:49 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> datagram_poll will judge the current socket status (EPOLLIN, EPOLLOUT)
> based on the traditional socket information (eg: sk_wmem_alloc), but
> this does not apply to xsk. So this patch uses sock_poll_wait instead of
> datagram_poll, and the mask is calculated by xsk_poll.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  net/xdp/xsk.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>

> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index b014197..0df8651 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -534,11 +534,13 @@ static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
>  static __poll_t xsk_poll(struct file *file, struct socket *sock,
>                              struct poll_table_struct *wait)
>  {
> -       __poll_t mask = datagram_poll(file, sock, wait);
> +       __poll_t mask = 0;
>         struct sock *sk = sock->sk;
>         struct xdp_sock *xs = xdp_sk(sk);
>         struct xsk_buff_pool *pool;
>
> +       sock_poll_wait(file, sock, wait);
> +
>         if (unlikely(!xsk_is_bound(xs)))
>                 return mask;
>
> --
> 1.8.3.1
>