Re: [dpdk-dev] [PATCH] examples/vhost: change the default value of NIC's max queues

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 9/10/21 5:17 AM, Xia, Chenbo wrote:
> Hi Wenwu,
> 
>> -----Original Message-----
>> From: Ma, WenwuX <wenwux.ma@intel.com>
>> Sent: Friday, September 10, 2021 9:52 PM
>> To: dev@dpdk.org
>> Cc: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>; Jiang,
>> Cheng1 <cheng1.jiang@intel.com>; Hu, Jiayu <jiayu.hu@intel.com>; Wang, Yinan
>> <yinan.wang@intel.com>; Ma, WenwuX <wenwux.ma@intel.com>
>> Subject: [PATCH] examples/vhost: change the default value of NIC's max queues
>>
>> vswitch can't launch with 40G FTV due to Device start fails
> 
> Not many people can understand what's FTV. So let's describe it with a driver
> name. Example if it's 'i40e':
> 
> vswitch can't launch with a 40G i40e port...
> 
> And Device -> device
> 
>> if NIC’s max queues > the default number of 128,
>> so, we changed the default value from 128 to 512.
>>
> 
> I'd say it's not cool to still hard-code the MAX_QUEUES so that only 'some' NICs
> can work with the example. The app should have a way to check this kind of info 
> before init/start. But as I would like to see at some point, this example will
> be removed and all our tests go to testpmd. Let's not waste too much effort on
> this example.

+1 on this, I agree with Chenbo it is better to invest time in porting
existing tests to testpmd.

> 
> Besides: it can be a fix. Let's backport it.
> 
> Thanks,
> Chenbo
>  
>> Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
>> ---
>>  examples/vhost/main.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
>> index bc3d71c898..36969a4de5 100644
>> --- a/examples/vhost/main.c
>> +++ b/examples/vhost/main.c
>> @@ -29,7 +29,7 @@
>>  #include "main.h"
>>
>>  #ifndef MAX_QUEUES
>> -#define MAX_QUEUES 128
>> +#define MAX_QUEUES 512
>>  #endif
>>
>>  /* the maximum number of external ports supported */
>> --
>> 2.25.1
>