Re: [dpdk-dev] vmxnet3 pmd dev restart

["Patel, Rashmin N" <rashmin.n.patel@intel.com>]

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