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From: Gopakumar Choorakkot Edakkunni <gopakumar.c.e@gmail.com>
Date: Mon, 19 Dec 2016 21:59:33 -0800
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To: huawei.xie@intel.com, dev@dpdk.org
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Subject: [dpdk-dev] Bug in virtqueue_dequeue_burst_rx()
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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 ?

virtio_recv_mergeable_pkts()
{
<snip>
    while (i < nb_used) {
        <snip>
*        num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);*
*        if (num != 1)*
*            continue;*
       <snip>
    }
<snip?
}

Rgds,
Gopa.