Re: [dpdk-dev] [PATCH 1/2] app/testpmd: fix invalid rxq number setting

["Dai, Wei" <wei.dai@intel.com>]

> -----Original Message-----
> From: Ananyev, Konstantin
> Sent: Tuesday, January 9, 2018 4:06 AM
> To: Dai, Wei <wei.dai@intel.com>; Lu, Wenzhuo <wenzhuo.lu@intel.com>;
> Wu, Jingjing <jingjing.wu@intel.com>; Peng, Yuan <yuan.peng@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org; Dai, Wei <wei.dai@intel.com>
> Subject: RE: [dpdk-dev] [PATCH 1/2] app/testpmd: fix invalid rxq number
> setting
> 
> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Wei Dai
> > Sent: Monday, January 8, 2018 1:03 PM
> > To: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Wu, Jingjing
> > <jingjing.wu@intel.com>; Peng, Yuan <yuan.peng@intel.com>
> > Cc: dev@dpdk.org; stable@dpdk.org; Dai, Wei <wei.dai@intel.com>
> > Subject: [dpdk-dev] [PATCH 1/2] app/testpmd: fix invalid rxq number
> > setting
> >
> > If an invalid RX queue is configured from testpmd command like "port
> > config all rxq number", the global variable rxq is updated by this
> > invalid value. It may cause testpmd crash.
> > This patch restores its last correct value when an invalid rxq number
> > configured is detected.
> >
> > Fixes: ce8d561418d4 ("app/testpmd: add port configuration settings")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Wei Dai <wei.dai@intel.com>
> > ---
> >  app/test-pmd/cmdline.c |  1 +
> >  app/test-pmd/testpmd.c | 10 ++++++++--  app/test-pmd/testpmd.h |
> 2
> > ++
> >  3 files changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
> > f71d963..3f3986c 100644
> > --- a/app/test-pmd/cmdline.c
> > +++ b/app/test-pmd/cmdline.c
> > @@ -1501,6 +1501,7 @@ cmd_config_rx_tx_parsed(void *parsed_result,
> >  			printf("Warning: Either rx or tx queues should be non zero\n");
> >  			return;
> >  		}
> > +		nb_rxq_bak = nb_rxq;
> >  		nb_rxq = res->value;
> >  	}
> >  	else if (!strcmp(res->name, "txq")) { diff --git
> > a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> > 47e145c..5939c88 100644
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -188,6 +188,8 @@ uint8_t dcb_test = 0;  queueid_t nb_rxq = 1; /**<
> > Number of RX queues per port. */  queueid_t nb_txq = 1; /**< Number of
> > TX queues per port. */
> >
> > +queueid_t nb_rxq_bak = 1; /**< Backup of last correct number of RX
> > +queues */
> > +
> >  /*
> >   * Configurable number of RX/TX ring descriptors.
> >   */
> > @@ -708,10 +710,14 @@ init_fwd_streams(void)
> >  		port = &ports[pid];
> >  		if (nb_rxq > port->dev_info.max_rx_queues) {
> 
> Why not to add that check in the function handler for " port config ... rxq ..."
> command itself?
> In that case you wouldn't need nb_rxq_bak at all.
> Konstantin

Thanks for your feedback, Konstantin.
I see your point. If that check is added in the function handler of command line,
same loop code will be repeated.

There are 2 ways to change nb_rxq:
1. with --rxq in the command line to start testpmd app to overwrite the default value 1
2. with "port config all rxq number" in the testpmd run time command line

How can your method correct an invalid input with --rxq in the command to start testpm app ?

By the way,  my v1 patch has a bug in case of more than 1 port with different maximum number of Rx queues.
For example,  the max_rx_queues of port 0 is 8 and that of port 1 is 4.
The previous valid rxq=4, if "port config all rxq 5" is run,
The nb_rxq_bak is updated to 5,  nb_rxq can't be restored to last correct value 4 for port 1.

I will fix bug in my v2 patch.

 
> 
> >  			printf("Fail: nb_rxq(%d) is greater than "
> > -				"max_rx_queues(%d)\n", nb_rxq,
> > -				port->dev_info.max_rx_queues);
> > +				"max_rx_queues(%d), restore to backup "
> > +				"rxq number(%d)\n", nb_rxq,
> > +				port->dev_info.max_rx_queues,
> > +				nb_rxq_bak);
> > +			nb_rxq = nb_rxq_bak;
> >  			return -1;
> >  		}
> > +		nb_rxq_bak = nb_rxq;
> >  		if (nb_txq > port->dev_info.max_tx_queues) {
> >  			printf("Fail: nb_txq(%d) is greater than "
> >  				"max_tx_queues(%d)\n", nb_txq,
> > diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h index
> > 4d7f27c..84246f7 100644
> > --- a/app/test-pmd/testpmd.h
> > +++ b/app/test-pmd/testpmd.h
> > @@ -391,6 +391,8 @@ extern uint64_t rss_hf;  extern queueid_t nb_rxq;
> > extern queueid_t nb_txq;
> >
> > +extern queueid_t nb_rxq_bak;
> > +
> >  extern uint16_t nb_rxd;
> >  extern uint16_t nb_txd;
> >
> > --
> > 2.7.5