From: Eric Dumazet <edumazet@google.com>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, netdev <netdev@vger.kernel.org>,
Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH net] virtio_net: Do not pull payload in skb->head
Date: Sun, 11 Apr 2021 23:23:20 +0200 [thread overview]
Message-ID: <CANn89iJa8KAnfWvUB8Jr8hsG5x_Amg90DbpoAHiuNZigv75MEA@mail.gmail.com> (raw)
In-Reply-To: <0f63dc52-ea72-16b6-7dcd-efb24de0c852@roeck-us.net>
On Sun, Apr 11, 2021 at 10:37 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 4/11/21 8:06 AM, Eric Dumazet wrote:
> > On Sun, Apr 11, 2021 at 3:43 PM Guenter Roeck <linux@roeck-us.net> wrote:
> >
> >> This patch causes a virtio-net interface failure when booting sh4 images
> >> in qemu. The test case is nothing special: Just try to get an IP address
> >> using udhcpc. If it fails, udhcpc reports:
> >>
> >> udhcpc: started, v1.33.0
> >> udhcpc: sending discover
> >> FAIL
> >>
> >
> > Can you investigate where the incoming packet is dropped ?
> >
>
> Unless I am missing something, packets are not dropped. It looks more
> like udhcpc gets bad indigestion in the receive path and exits immediately.
> Plus, it doesn't happen all the time; sometimes it receives the discover
> response and is able to obtain an IP address.
>
> Overall this is quite puzzling since udhcpc exits immediately when the problem
> is seen, no matter which option I give it on the command line; it should not
> really do that.
Could you strace both cases and report differences you can spot ?
strace -o STRACE -f -s 1000 udhcpc
next prev parent reply other threads:[~2021-04-11 21:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-02 13:26 [PATCH net] virtio_net: Do not pull payload in skb->head Eric Dumazet
2021-04-06 2:03 ` Jason Wang
2021-04-07 18:09 ` Michael S. Tsirkin
2021-04-11 13:43 ` Guenter Roeck
2021-04-11 15:06 ` Eric Dumazet
2021-04-11 20:37 ` Guenter Roeck
2021-04-11 21:23 ` Eric Dumazet [this message]
2021-04-11 21:32 ` Guenter Roeck
2021-04-11 21:43 ` Eric Dumazet
2021-04-11 22:07 ` Guenter Roeck
2021-04-12 5:48 ` Eric Dumazet
2021-04-12 5:53 ` Eric Dumazet
2021-04-12 6:23 ` Guenter Roeck
2021-04-12 6:37 ` Eric Dumazet
2021-04-11 22:20 ` Guenter Roeck
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