From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Gopakumar Choorakkot Edakkunni <gopakumar.c.e@gmail.com>
Cc: huawei.xie@intel.com, dev@dpdk.org
Subject: Re: [dpdk-dev] Bug in virtqueue_dequeue_burst_rx()
Date: Thu, 22 Dec 2016 15:38:34 +0800 [thread overview]
Message-ID: <20161222073834.GZ18991@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <CABK1yFBkaePG37Qd2ebobgJtdeVMj1uNZi5szprFkfyZ5CFZuw@mail.gmail.com>
On Mon, Dec 19, 2016 at 09:59:33PM -0800, Gopakumar Choorakkot Edakkunni wrote:
> While I was testing virtio with ubuntu 14.04 kvm as host and dpdk16.07
> linux as guest, quite often I have seen that I get into a situation where
> virtio_recv_mergeable_pkts() gets into a forever loop, after sending
> traffic for a while. In the below API, I see that it clearly leads to a
> while loop, I am not quite familiar with virtio or mergeable buffers, so
> thought of checking with dpdk alias on the intent here.
>
> I checked the linux kernel virtio_net.c file which does the similar
> mergeable recieve, and the kernel code breaks out in case of error.
> Shouldnt dpdk be breaking out of here on error instead of continue ?
Yep, that looks buggy.
>
> virtio_recv_mergeable_pkts()
> {
> <snip>
> while (i < nb_used) {
> <snip>
> * num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);*
> * if (num != 1)*
> * continue;*
However, normally, virtqueue_dequeue_burst_rx() would be successful
here: the outer check (i < nb_used) somehow ascertains it.
Two options I can think of so far:
- will it go back working once you do "break" here?
- tell us how you managed to trigger this issue, so that I could
also reproduce it that I can debug it.
--yliu
next prev parent reply other threads:[~2016-12-22 7:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-20 5:59 Gopakumar Choorakkot Edakkunni
2016-12-22 7:38 ` Yuanhan Liu [this message]
2017-01-09 9:38 ` Gopakumar Choorakkot Edakkunni
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