[dpdk-dev] [PATCH] net/tap: driver closing tx interface on queue setup

Ferruh Yigit ferruh.yigit at intel.com
Mon Jan 30 18:19:20 CET 2017


On 1/30/2017 2:38 PM, Pascal Mazon wrote:
> On 01/30/2017 12:00 PM, Ferruh Yigit wrote:> On 1/29/2017 2:12 AM, Keith 
> Wiles wrote:
>>> The tap driver setup both rx and tx file descriptors when the
>>> rte_eth_rx_queue_setup() causing the tx to be closed when tx setup
>>> was called.
>>
>> Can you please describe the problem more.
>> Without this patch rx->fd == tx->fd, with this patch rx and tx has
>> different file descriptors.
>>
>> What was the wrong with rx and tx having same fd?
>>
>> As far as I can see, rte_eth_rx_queue_setup() won't close tx->fd, that
>> function will do nothing if rx or tx has valid fd.
>>
>>>
>>> Signed-off-by: Keith Wiles <keith.wiles at intel.com>
>>
>> <...>
>>
> 
> Hi,
> 
> The tap PMD recently broke for me because of this patch [1].
> 
> During init (eth_dev_tap_create()), the tap PMD allocates a shared RX/TX 
> queue through tun_alloc().
> The recent patch now releases existing queues in rx_queue_setup(), 
> before adding new ones.
> 
> When rx_queue_setup() is called, it uses close() calls on all shared 
> queues, effectively deleting the netdevice.
> That's the main issue here.
> 
> I tested Keith's patch [2], and it fixes that issue, using separate queues.

Thanks for the clarification, and I am adding following patch to patch [2]:

Tested-by: Pascal Mazon <pascal.mazon at 6wind.com>

<...>

> 
> [1] d00d7cc88335 ("ethdev: release queue before setting up")
> [2] http://dpdk.org/ml/archives/dev/2017-January/056470.html
> 
> 



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