Re: [dpdk-dev] [PATCH 1/3] app/testpmd: fix forwarding configuration when DCB test

[oulijun <oulijun@huawei.com>]

在 2021/3/23 16:55, Li, Xiaoyun 写道:
> Hi
> 
>> -----Original Message-----
>> From: Lijun Ou <oulijun@huawei.com>
>> Sent: Friday, March 5, 2021 18:22
>> To: Yigit, Ferruh <ferruh.yigit@intel.com>
>> Cc: Li, Xiaoyun <xiaoyun.li@intel.com>; dev@dpdk.org;
>> linuxarm@openeuler.org
>> Subject: [PATCH 1/3] app/testpmd: fix forwarding configuration when DCB test
>>
>> From: Huisong Li <lihuisong@huawei.com>
>>
> The commit message is too long and redundant. Please simplify it.
> 
>> 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 lack for
>> dcb_fwd_config_setup, which may lead to a bad events where multiple polling
>> threads operate on the same queue. As a result, various possible exceptions will
>> occur. The procedure is as follows:
>>
>> startup testpmd app as follows:
>> testpmd> port stop all
>> testpmd> set nbcore 8
>> testpmd> port config 0 dcb vt off 4 pfc on port config all rxq 16 port
>> testpmd> config all txq 16 port start all set fwd mac
>> Logical Core 1 (socket 0) forwards packets on 4 streams:
>> RX P=0/Q=0 (socket 0) -> TX P=0/Q=0 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=1 (socket 0) -> TX P=0/Q=1 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=2 (socket 0) -> TX P=0/Q=2 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=3 (socket 0) -> TX P=0/Q=3 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 2 (socket 0) forwards packets on 4 streams:
>> RX P=0/Q=4 (socket 0) -> TX P=0/Q=4 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=5 (socket 0) -> TX P=0/Q=5 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=6 (socket 0) -> TX P=0/Q=6 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=7 (socket 0) -> TX P=0/Q=7 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 3 (socket 0) forwards packets on 4 streams:
>> RX P=0/Q=8 (socket 0) -> TX P=0/Q=8 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=9 (socket 0) -> TX P=0/Q=9 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=10 (socket 0) -> TX P=0/Q=10 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=11 (socket 0) -> TX P=0/Q=11 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 4 (socket 0) forwards packets on 4 streams:
>> RX P=0/Q=12 (socket 0) -> TX P=0/Q=12 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=13 (socket 0) -> TX P=0/Q=13 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=14 (socket 0) -> TX P=0/Q=14 (socket 0) peer=02:00:00:00:00:00 RX
>> P=0/Q=15 (socket 0) -> TX P=0/Q=15 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 5 (socket 0) forwards packets on 1 streams:
>> RX P=0/Q=4 (socket 0) -> TX P=0/Q=4 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 6 (socket 0) forwards packets on 1 streams:
>> RX P=0/Q=5 (socket 0) -> TX P=0/Q=5 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 7 (socket 0) forwards packets on 1 streams:
>> RX P=0/Q=6 (socket 0) -> TX P=0/Q=6 (socket 0) peer=02:00:00:00:00:00 Logical
>> Core 8 (socket 0) forwards packets on 1 streams:
>> RX P=0/Q=7 (socket 0) -> TX P=0/Q=7 (socket 0) peer=02:00:00:00:00:00
>>
>> Notice: number of rxq and txq in running cmdline are greater than used nb_tc.
>>
>> For the DCB forwarding test, each core is assigned on each traffic class and each
>> core is assigned a multi-stream. Therefore, 'nb_fwd_lcores'
>> value can be adjusted based on 'total_tc_num' in all forwarding ports.
>>
>> In addition, after operation of port stop/port start, forwarding configuration is
>> changed by rss_fwd_config_setup. In "start_port"
>> function, dcb_test is set to 1 based on dcb_config. So it also should be cleared
>> when dcb_config is 0.
>>
>> 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 +++++++++++++++++++  app/test-pmd/testpmd.c |
>> 12 +++++++-----
>>   2 files changed, 26 insertions(+), 5 deletions(-)
>>
>> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c index
>> 576d5ac..c89f8cd 100644
>> --- a/app/test-pmd/config.c
>> +++ b/app/test-pmd/config.c
>> @@ -2864,6 +2864,21 @@ 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;
>> +}
> 
> It's only 3 lines. Is it really necessary to make it into a function which is not called by anyone else? A comment and the loop are enough.
> 
To calculate the total number of TCs on all forwarding ports, we have to 
call  rte_eth_dev_get_dcb_info().  However,  rte_eth_dev_get_dcb_info()
has been called twice by dcb_fwd_config_setup() to setup dcb forwarding 
configuration. The dcb_fwd_config_setup() might be more readable
if encapsulated, I think.  In addition, variables in "cur_fwd_config" 
are initialized more centrally. What do you think?
>> +
>>   /**
>>    * For the DCB forwarding test, each core is assigned on each traffic class.
>>    *
>> @@ -2883,12 +2898,16 @@ 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 = 0;
>>   	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();
>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
>> 1a57324..7eb810b 100644
>> --- a/app/test-pmd/testpmd.c
>> +++ b/app/test-pmd/testpmd.c
>> @@ -2707,14 +2707,16 @@ stop_port(portid_t pid)
>>   	portid_t peer_pl[RTE_MAX_ETHPORTS];
>>   	int peer_pi;
>>
>> -	if (dcb_test) {
>> -		dcb_test = 0;
>> -		dcb_config = 0;
>> -	}
>> -
>>   	if (port_id_is_invalid(pid, ENABLED_WARN))
>>   		return;
>>
>> +	/*
>> +	 * In "start_port" function, dcb_test is set to 1 based on dcb_config.
>> +	 * So it should be cleared when dcb_config is 0.
>> +	 */
>> +	if (dcb_config == 0)
>> +		dcb_test = 0;
>> +
> 
> I don't understand why are you changing this.
> dcb_test will only be set when dcb_config is 1 when starting ports. And both dcb_test and dcb_config will be cleared when stopping ports.
> So dcb will only affect when you set port dcb and then start port and when stop port dcb will be cleared.
> 
> So what's the problem of original codes?
> 
> Your change will cause issues that there's no place to set dcb_config as 0. If you config dcb, then it'll be always dcb mode unless restart the whole testpmd.
> 
>>   	printf("Stopping ports...\n");
>>
>>   	RTE_ETH_FOREACH_DEV(pi) {
>> --
>> 2.7.4
> 
> .
>