[dpdk-dev] traffic no longer readable...

[Jeff Weeks <jweeks@neuraldk.org>]

Hello all,

I've been developing with dpdk, using virtio, and I'm noticing that I can 
often get into a state whereby I no longer receive any packets.

The call to rte_eth_rx_burst always returns 0, indicating the rx queue is 
empty.

How is this queue filled?  I see there is a dpdk thread, which waits on an 
epoll fd for interrupts.  I set a breakpoint here, and it appeared as though 
we were waiting forever on the epoll fd.  This, to me, seemed to be the source 
of the issue I'm seeing (presumably interrupts cause us to read off the nic and 
fill the queue?)... but, oddly enough, I see the same behaviour even when I'm 
receiving packets.

Have I misinterpreted how this is supposed to work?  Or is gdb behaving poorly 
for me (wouldn't be surprising...).

What/how else can I further investigate this?

Thanks,
Jeff