Re: [dpdk-dev] [PATCH V3 1/7] app/testpmd: fix forward lcores number when DCB test

["Li, Xiaoyun" <xiaoyun.li@intel.com>]

> -----Original Message-----
> From: Huisong Li <lihuisong@huawei.com>
> Sent: Tuesday, April 20, 2021 17:01
> To: dev@dpdk.org
> Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; Li, Xiaoyun <xiaoyun.li@intel.com>;
> linuxarm@openeuler.org; lihuisong@huawei.com
> Subject: [PATCH V3 1/7] app/testpmd: fix forward lcores number when DCB test
> 
> Currently, 'nb_fwd_lcores' value are both adjusted based on 'nb_fwd_streams' in
> rss/simple/icmp_echo_fwd_config_setup.
> But the operation is missing in dcb_fwd_config_setup, which may lead to a bad
> behavior in which multiple polling threads operate on the same queue. In this
> case, the device sends and receives packets, causing unexpected results. The
> procedure is  as follows:
> 1/ run testpmd with "--rxq=8 --txq=8"
> 2/ port stop all
> 3/ set nbcore 8
> 4/ port config 0 dcb vt off 4 pfc on
> 5/ port config all rxq 16
> 6/ port config all txq 16
> 7/ port start all
> 8/ set fwd mac
> 9/ start
> 
Same as v2 comment.
Please check that.

> For the DCB forwarding test, each core is assigned to each traffic class and each
> core is assigned a multi-stream.
> Therefore, 'nb_fwd_lcores' value needs to be adjusted based  on 'total_tc_num'
> in all forwarding ports.
> 
> Fixes: 900550de04a7 ("app/testpmd: add dcb support")
> Fixes: ce8d561418d4 ("app/testpmd: add port configuration settings")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> Signed-off-by: Lijun Ou <oulijun@huawei.com>
> ---
>  app/test-pmd/config.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c index
> ccb9bd3..03ee40c 100644
> --- a/app/test-pmd/config.c
> +++ b/app/test-pmd/config.c
> @@ -2961,6 +2961,21 @@ rss_fwd_config_setup(void)
>  	}
>  }
> 
> +static uint16_t
> +get_fwd_port_total_tc_num(void)
> +{
> +	struct rte_eth_dcb_info dcb_info;
> +	uint16_t total_tc_num = 0;
> +	unsigned int i;
> +
> +	for (i = 0; i < nb_fwd_ports; i++) {
> +		(void)rte_eth_dev_get_dcb_info(fwd_ports_ids[i], &dcb_info);
> +		total_tc_num += dcb_info.nb_tcs;
> +	}
> +
> +	return total_tc_num;
> +}
> +
>  /**
>   * For the DCB forwarding test, each core is assigned on each traffic class.
>   *
> @@ -2980,12 +2995,16 @@ dcb_fwd_config_setup(void)
>  	lcoreid_t  lc_id;
>  	uint16_t nb_rx_queue, nb_tx_queue;
>  	uint16_t i, j, k, sm_id = 0;
> +	uint16_t total_tc_num;
>  	uint8_t tc = 0;
> 
>  	cur_fwd_config.nb_fwd_lcores = (lcoreid_t) nb_fwd_lcores;
>  	cur_fwd_config.nb_fwd_ports = nb_fwd_ports;
>  	cur_fwd_config.nb_fwd_streams =
>  		(streamid_t) (nb_rxq * cur_fwd_config.nb_fwd_ports);
> +	total_tc_num = get_fwd_port_total_tc_num();
> +	if (cur_fwd_config.nb_fwd_lcores > total_tc_num)
> +		cur_fwd_config.nb_fwd_lcores = total_tc_num;
> 
>  	/* reinitialize forwarding streams */
>  	init_fwd_streams();
> --
> 2.7.4