Re: [dpdk-dev] vmxnet3 pmd dev restart

["Cao, Waterman" <waterman.cao@intel.com>]

Hi Rashmin,

 We found similar issue when we start/stop vmnet dev several time. (> 3 times)
 It happens kernel panic, and sometimes kernel will occur core dump.
 Let me know if you want to submit patch to fix it.
 
Thanks
Waterman 

-----Original Message-----
>From: Patel, Rashmin N 
>Sent: Friday, October 10, 2014 6:07 AM
>To: Navakanth M; stephen@networkplumber.org; Cao, Waterman
>Cc: dev@dpdk.org
>Subject: RE: vmxnet3 pmd dev restart
>
>I just quickly looked into the code and instead of releasing memory or simply set it to NULL (patch: 
> http://thread.gmane.org/gmane.comp.networking.dpdk.devel/4683), you can zero it out and it should work perfectly, you can give it a quick try.
>
>//rte_free(ring->buf_info);
>memset(ring->buf_info, 0x0, ring->size*sizeof(vmxnet3_buf_info_t));
>
>This will not free the memory from heap but just wipe it out to 0x0, provided that we freed all the mbuf(s) pointed by each buf_info->m pointers. Hence you won't need to reallocate it when you start device after this stop.
>
>Thanks,
>Rashmin
>
>-----Original Message-----
>From: Navakanth M [mailto:navakanthdev@gmail.com]
>Sent: Wednesday, October 08, 2014 10:11 PM
>To: stephen@networkplumber.org; Patel, Rashmin N; Cao, Waterman
>Cc: dev@dpdk.org
>Subject: Re: vmxnet3 pmd dev restart
>
>I had tried with Stephen's patch but after stop is done and when we call start it crashed at vmxnet3_dev_start()->
>vmxnet3_dev_rxtx_init()->vmxnet3_post_rx_bufs() as buf_info is freed and is not allocated again. buf_info is allocated in
>vmxnet3_dev_rx_queue_setup() which would be called once at the initialization only.
>I also tried not freeing buf_info in stop but then i see different issue after start, packets are not received due to check while (rcd->gen == rxq->comp_ring.gen) { in vmxnet3_recv_pkts()
>
>Waterman, Have you got chance to test stop and start of vmnet dev if so did you notice any issue similar to this?
>
>Thanks
>Navakanth
>
>On Thu, Oct 9, 2014 at 12:46 AM, Patel, Rashmin N <rashmin.n.patel@intel.com> wrote:
>> Yes I had a local copy working with couple of lines fix. But someone else, I think Stephen added a fix patch for the same, and I assume if it's been merged, should be working, so did not follow up later.
>>
>> I don't have a VMware setup handy at moment but I think Waterman would have more information about testing that patch if he has found any issue with it.
>>
>> Thanks,
>> Rashmin
>>
>> -----Original Message-----
>> From: Navakanth M [mailto:navakanthdev@gmail.com]
>> Sent: Wednesday, October 08, 2014 4:14 AM
>> To: dev@dpdk.org; Patel, Rashmin N
>> Subject: Re: vmxnet3 pmd dev restart
>>
>> Hi Rashmin
>>
>> I have come across your reply in following post that you have worked on this problem and would submit the patch for it.
>> Can you please share information on the changes you worked on or patch log if you had submitted any for it?
>> http://thread.gmane.org/gmane.comp.networking.dpdk.devel/4683
>>
>> Thanks
>> Navakanth
>>
>> On Tue, Sep 30, 2014 at 1:44 PM, Navakanth M <navakanthdev@gmail.com> wrote:
>>> Hi
>>>
>>> I am using DPDKv1.7.0 running on Vmware Esxi 5.1 and am trying to 
>>> reset the port which uses pmd_vmnet3 library functions from below 
>>> function calls.
>>> rte_eth_dev_stop
>>> rte_eth_dev_start
>>>
>>> Doing this, i face panic while rte_free(ring->buf_info) in 
>>> Vmxnet3_cmd_ring_release().
>>> I have gone through following thread but the patch mentioned didn't 
>>> help rather it crashed in start function while accessing buf_info in 
>>> vmxnet3_post_rx_bufs. I see this buf_info is allocated in queue setup 
>>> functions which are called at initialization.
>>> http://thread.gmane.org/gmane.comp.networking.dpdk.devel/4683
>>>
>>> I tried not freeing it and then rx packets are not received due to 
>>> mismatch in while (rcd->gen == rxq->comp_ring.gen) in
>>> vmxnet3_recv_pkts()
>>>
>>> To reset the device port, is this the right way what i am doing?
>>> Or do I have to call vmxnet3_dev_tx_queue_setup()
>>> vmxnet3_dev_rx_queue_setup() once stop is called? I have checked 
>>> recent patches and threads but did not get much information on this.
>>>
>>> Thanks
>>> Navakanth