[dpdk-dev] kernel panic when stop my test demo

[Richardson, Bruce]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Lilijun
> Sent: Wednesday, October 15, 2014 10:43 AM
> To: dev at dpdk.org; stephen at networkplumber.org
> Subject: Re: [dpdk-dev] kernel panic when stop my test demo
> 
> Hi all,
> 
> After adding unmap uio resources operations in process signal handler functions,
> An new error was found as follows:
> Call Trace:
>  [<ffffffffa01cd530>] uio_release+0x40/0x60 [uio]
>  [<ffffffff811b1329>] __fput+0xe9/0x270
>  [<ffffffff811b15fe>] ____fput+0xe/0x10
>  [<ffffffff810823c7>] task_work_run+0xa7/0xe0
>  [<ffffffff81012a77>] do_notify_resume+0x97/0xb0
>  [<ffffffff815f2a92>] int_signal+0x12/0x17
> 
> The code for unmap uio resources is shown:
> static void pci_dev_uio_unmap(struct rte_pci_device *pci_dev, uint8_t port_id)
> {
>         int i;
> 
>         RTE_LOG(INFO, EAL, "begin unmap port %d uio resource! \n", port_id);
>         if (NULL == pci_dev)
>         {
>                 RTE_LOG(ERR, EAL, "begin unmap port %d uio resource! \n", port_id);
>                 return;
>         }
> 
>         for (i = 0; i != PCI_MAX_RESOURCE; i++)
>         {
>                 /* skip empty BAR */
>                 if (0 == pci_dev->mem_resource[i].phys_addr)
>                         continue;
>                 if (munmap(pci_dev->mem_resource[i].addr, pci_dev-
> >mem_resource[i].len)
>                                                                         == -1){
>                         RTE_LOG(ERR, EAL, "Error with munmap\n");
>                         return;
>                 }
>         }
>         if (close(pci_dev->intr_handle.fd) == -1){
>                 RTE_LOG(ERR, EAL, "Error closing interrupt handle\n");
>                 return;
>         }
>         pci_dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
>         RTE_LOG(INFO, EAL, "unmap port %d uio resource successfully!\n",
> port_id);
> }
> 
> Does anyone has some ideas?
> 
> Thanks for any help.
> Jerry
> 
> On 2014/10/14 19:58, Lilijun wrote:
> > Hi Stephen and all,
> >
> > I have a same problem as this older email describes on Aug 14, 2013.
> > Any help will be appreciated.
> >
> > The details is shown as follows.
> > The key step implementation of my demo is:
> > 1. Firstly, call rte_eal_init() to do some initialization.
> > 2. Switch the driver of my Intel  82599 NIC from ixgbe.ko to igb_uio.ko
> > like tools/dpdk_nic_bind.py written in C source code.
> > 3. Configure rte_dev and start it.
> > 4. Do some rx/tx tests.
> > 5. call rte_eth_dev_stop(dpdk_port_id) to stop the hardware as your history
> emails.
> > 6. Switch the driver of the NIC from igb_uio.ko to ixgbe.ko.
> > 7. Kill the demo using commands: kill -9.

Just to clarify one point - you have an application running which was using the NICs with DPDK while you remove the uio driver and replace it with ixgbe? I would expect doing such a thing to cause problems as stopping the device does not cause the NIC BAR memory to be unmapped from the DPDK process. Therefore removing the driver providing that memory map and getting another driver to start using those same BARs would not be recommended.

/Bruce