RE: [PATCH 4/4] mempool: use lcore API to check if lcore ID is valid

[Konstantin Ananyev <konstantin.ananyev@huawei.com>]

> 
> Use lcore API to check if the lcore ID is valid. The runtime
> check does not add much value.

From my perspective it adds a perfect value:
Only threads with valid lcore id have their own default mempool cache.

> Hence use assert to validate
> the lcore ID.

Wonder why?
What's wrong for the thread to try to get default mempool cache?
That would change existing behavior and in general seems wrong to me.  
So I am strongly opposed.
 
> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Wathsala Vithanage <wathsala.vithanage@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
>  lib/mempool/rte_mempool.h | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
> index 009bd10215..00c5aa961b 100644
> --- a/lib/mempool/rte_mempool.h
> +++ b/lib/mempool/rte_mempool.h
> @@ -1314,10 +1314,9 @@ rte_mempool_cache_free(struct rte_mempool_cache *cache);
>  static __rte_always_inline struct rte_mempool_cache *
>  rte_mempool_default_cache(struct rte_mempool *mp, unsigned lcore_id)
>  {
> -	if (mp->cache_size == 0)
> -		return NULL;
> +	RTE_ASSERT(rte_lcore_id_is_valid(lcore_id));
> 
> -	if (lcore_id >= RTE_MAX_LCORE)
> +	if (mp->cache_size == 0)
>  		return NULL;
> 
>  	rte_mempool_trace_default_cache(mp, lcore_id,
> --
> 2.25.1
>