Re: [dpdk-dev] [PATCH] ixgbe: fix segmentation fault when start secondary process

["De Lara Guarch, Pablo" <pablo.de.lara.guarch@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Qiu, Michael
> Sent: Thursday, December 18, 2014 10:22 AM
> To: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] ixgbe: fix segmentation fault when start
> secondary process
> 
> On 12/18/2014 6:17 PM, Qiu, Michael wrote:
> > EAL:   probe driver: 8086:10fb rte_ixgbe_pmd
> > EAL:   PCI memory mapped at 0x7f18c2a00000
> > EAL:   PCI memory mapped at 0x7f18c2a80000
> > Segmentation fault (core dumped)
> >
> > This is introduced by commit: 46bc9d75
> > 	ixgbe: fix multi-process support
> > When start primary process with command line:
> > ./app/test/test -n 1 -c ffff -m 64
> > then start the second one:
> > ./app/test/test -n 1 --proc-type=secondary --file-prefix=rte
> > This segment-fault will occur.
> >
> > Root cause is test app on primary process only starts device, but
> > the queue need initialized by manually command line.
> > So the tx queue is still NULL when secondary process startup.
> >
> > Reported-by: Yong Liu <yong.liu@intel.com>
> > Signed-off-by: Michael Qiu <michael.qiu@intel.com>
> > ---
> >  lib/librte_pmd_ixgbe/ixgbe_ethdev.c | 16 +++++++++++++---
> >  1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> > index 9401916..87ed6ee 100644
> > --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> > +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> > @@ -749,9 +749,19 @@ eth_ixgbe_dev_init(__attribute__((unused))
> struct eth_driver *eth_drv,
> >  	 */
> >  	if (rte_eal_process_type() != RTE_PROC_PRIMARY){
> >  		struct igb_tx_queue *txq;
> > -		/* TX queue function in primary, set by last queue initialized
> */
> > -		txq = eth_dev->data->tx_queues[eth_dev->data-
> >nb_tx_queues-1];
> > -		set_tx_function(eth_dev, txq);
> > +		/* TX queue function in primary, set by last queue initialized
> > +		 * Tx queue may not initialized by primary process
> > +		 * */
> > +		if (eth_dev->data->tx_queues) {
> > +			txq = eth_dev->data->tx_queues[eth_dev->data-
> >nb_tx_queues-1];
> > +			set_tx_function(eth_dev, txq);
> > +		} else {
> > +			/* Shall we exit this process if we get here? */
> 
> I'm just not sure if it is better to terminated when Tx queues are NULL
> in secondary process.
> 
Well, in case of test app, it does not need any ports, so it should work anyway.
Probably it does not make much sense to run two test processes in general,
although it is used in multiprocess unit test.

So, I would say that app should not terminate.
> Thanks
> Michael
> > +			PMD_INIT_LOG(INFO, "Last tx queue initialized fail in
> "
> > +				     "secondary process, please verify if tx "
> > +				     "queues were initialized in primary "
> > +				     "process!\n");
> > +		}
> >
> >  		if (eth_dev->data->scattered_rx)
> >  			eth_dev->rx_pkt_burst =
> ixgbe_recv_scattered_pkts;