Re: [PATCH v2] examples/vhost: reduce number of hugepages needed

[Panu Matilainen <pmatilai@redhat.com>]

On 12/10/2015 04:50 PM, Ananyev, Konstantin wrote:
>
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Bernard Iremonger
>> Sent: Thursday, December 10, 2015 1:53 PM
>> To: dev@dpdk.org
>> Subject: [dpdk-dev] [PATCH v2] examples/vhost: reduce number of hugepages needed
>>
>> Change MAX_QUEUES from 512 to 128 to reduce the number of hugepages
>> required by the vhost-switch program.
>>
>> Changes in v2:
>> remove comment added before #define MAX_QUEUES in v1 patch.
>>
>> Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
>> Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>
>
> Wasn't it increased a while ago, because someone complained that
> 128 queues might not be enough on FVL?
>  From git log I can see that it was first increased from 128 to 256,
> then from 256 to 512.
> The reason mentioned - HW that has bigger number of queues.
> Isn't it not the case anymore?
> If yes, why?
>
> BTW, shouldn't it be then at least:
>
> +#ifndef MAX_QUEUES
> +#define MAX_QUEUES 128
> +#endif
>
> So people can just do -D MAX_QUEUES=X at build time if they like(need) to.

Being subject to constant changes back and forth suggests this really 
should be a runtime tunable rather than build time constant.

	- Panu -