> On Jan 31, 2017, at 9:44 AM, Pascal Mazon <pascal.ma...@6wind.com> wrote:
>
> On 01/31/2017 04:44 PM, Wiles, Keith wrote:
>>
>>> On Jan 31, 2017, at 9:38 AM, Yigit, Ferruh <ferruh.yi...@intel.com> wrote:
>>>
>>> On 1/31/2017 3:30 PM, Pascal Mazon wrote:
>>>> On 01/31/2017 04:28 PM, Ferruh Yigit wrote:
>>>>> On 1/31/2017 2:23 PM, Pascal Mazon wrote:
>>>>>> On 01/31/2017 02:06 PM, Ferruh Yigit wrote:> On 1/31/2017 9:42 AM,
>>>>>> Pascal Mazon wrote:
>>>>>>>> dev->data->name contains "net_tap", the device driver name.
>>>>>>>
>>>>>>> I see what patch does, just as a note to commit log:
>>>>>>>
>>>>>>> AFAIK, "dev->data->name" is device name, and for this case it is
>>>>>>> "net_tap#", like "net_tap0", "net_tap1" ...
>>>>>>>
>>>>>>> "dev->data_drv_name" is the driver name which is "net_tap"
>>>>>>
>>>>>> Indeed, dev->data->name is the device name, looking like "net_tap#",
>>>>>> with number increasing for each vdev.
>>>>>> I'll put the following commit log line if that's ok:
>>>>>>
>>>>>> dev->data->name contains the device name, e.g. "net_tap0".
>>>>>>
>>>>>>>
>>>>>>>> dev->data->dev_private->name contains the actual iface name,
>>>>>>>> e.g. "dtap0".
>>>>>>>
>>>>>>> Right, I agree this is correct comparing "dev->data->name"
>>>>>>>
>>>>>>> But the problem is pmd->name is per eth_dev.
>>>>>>>
>>>>>>> If I read code correct, for multiple queue support, each queue pair will
>>>>>>> create a tap device, so each needs a different name.
>>>>>>>
>>>>>>> So can't just use pmd->name. Need to create a name per queue pair, it
>>>>>>> can be combination of pmd->name + "_" + queue_id? Or can keep a name per
>>>>>>> queue pair, instead of eth_dev.
>>>>>>>
>>>>>>> What do you think?
>>>>>>
>>>>>> Actually that's not exactly how it goes.
>>>>>> Adding a queue to a netdevice requires to open("/dev/net/tun") and
>>>>>> setting
>>>>>> TUNSETIFF (through ioctl) on the resulting fd.
>>>>>> That's the important part: queues for a given tap device must set
>>>>>> TUNSETIFF
>>>>>> with a common ifreq.ifr_name (in our case, pmd->name).
Looking at the changes to set the link up/down and the adding the two
functions. I noticed in the stop/start routines I was set the link in DPDK and
not adjusting the interface link. Should the stop/start routine also do the
same thing?
>>>>>>
>>>>>> This is best explained in the kernel doc, there:
>>>>>
>>>>> Thank you for the clarification.
>>>>> If so, why PMD keeps a fd per queue?
>>>>>
>>>>> Overall, patch looks good except mentioned detail in commit log.
>>>>>
>>>>> I suggest waiting Keith's patch, and rebase this set on top of it.
>>>>>
>>>>> Thanks,
>>>>> ferruh
>>>>>
>>>>>>
>>>>>> [1]
>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/tuntap.txt#n108
>>>>>>
>>>>> <...>
>>>>>
>>>>
>>>> I would say it is because dev->{r/t}x_pkt_burst() is done per queue.
>>>> In these functions, we need to make our read() and write() accesses on the
>>>> right fd considering the queue we're required to process.
>>>
>>> If fd is same for all queues, it is possible to keep one instance in pmd
>>> private_data, and access it from queues. I think it is confusing to have
>>> multiple copy of it, but I see your point.
>>
>> In my changes I removed the fds[] array as it was not required only the
>> rx/tx_queue has an fd variable.
>
> Sounds good to me.
>
> Ferruh, just to make sure we're on the same page, in multiqueue, there is
> definitely a different fd for each queue.
>
>>
>>>
>>>>
>>>> I'll wait for Keith's patch, then.
>>>
>>> Thanks again.
>>>
>>>>
>>>> Best regards,
>>
>> Regards,
>> Keith
>>
>
>
> --
> Pascal Mazon
> www.6wind.com
Regards,
Keith
