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From: "sunyucong@gmail.com" <sunyucong@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Jiang Wang <jiang.wang@bytedance.com>,
	Cong Wang <cong.wang@bytedance.com>,
	Yucong Sun <fallentree@fb.com>,
	Andrii Nakryiko <andrii@kernel.org>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf-next] selftests/bpf: reduce more flakyness in sockmap_listen
Date: Wed, 1 Sep 2021 23:34:45 -0400	[thread overview]
Message-ID: <CAJygYd2f8S5Oq_B8724p-3rQvXaJKMBGgBKLS_0R7fxTew2oeA@mail.gmail.com> (raw)
In-Reply-To: <CAM_iQpUG30QL03Uh9D_ACy_29TLWG+YfDO9_GvcqzW2f0TbpYw@mail.gmail.com>

On Wed, Sep 1, 2021 at 9:33 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> On Tue, Aug 31, 2021 at 12:33 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
> > Like I mentioned before, I suspect there is some delay in one of
> > the queues on the way or there is a worker wakeup latency.
> > I will try adding some tracepoints to see if I can capture it.
> >
>
> I tried to revert this patch locally to reproduce the EAGAIN
> failure, but even after repeating the sockmap_listen test hundreds
> of times, I didn't see any failure here.
>
> If you are still interested in this issue, I'd suggest you adding some
> tracepoints to see what happens to kworker or the packet queues.
>
> It does not look like a sockmap bug, otherwise I would be able to
> reproduce it here.
>

Cong, the issue is not that read() sometimes returns EAGAIN.

It is that when using select on the redirected socket,  it will hang forever.

> Thanks.

  reply	other threads:[~2021-09-02  3:35 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-25 18:47 [PATCH bpf-next] selftests/bpf: reduce more flakyness in sockmap_listen Yucong Sun
2021-08-26  1:04 ` Alexei Starovoitov
2021-08-26  2:37   ` sunyucong
2021-08-26 18:18     ` sunyucong
2021-08-26 19:07       ` Alexei Starovoitov
2021-08-26 19:23         ` sunyucong
2021-08-26 21:05           ` Alexei Starovoitov
2021-08-26 21:07             ` sunyucong
2021-08-31 19:33         ` Cong Wang
2021-09-02  1:33           ` Cong Wang
2021-09-02  3:34             ` sunyucong [this message]
2021-09-03 23:44               ` Cong Wang
2021-09-07  2:24                 ` sunyucong
2021-09-15 14:13                   ` sunyucong
2021-09-15 16:54                   ` Cong Wang

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