RE: [PATCH v2 2/3] mempool: fix dump of unpopulated pool

["Morten Brørup" <mb@smartsharesystems.com>]

Good progress, Robert.

One more change requested, see comments inline below.

> +/*
> + * Check whether the mempool driver has allocated its store. Mempools
> are on
> + * the mempool list before that, so rte_mempool_dump() and
> rte_mempool_walk()
> + * callbacks can find them while another thread populates them.
> + * Acquire: pairs with the release in mempool_ops_alloc_once().
> + */
> +static bool
> +mempool_is_created(const struct rte_mempool *mp)
> +{
> +	return (rte_atomic_load_explicit(
> +			(const RTE_ATOMIC(unsigned int) *)&mp->flags,
> +			rte_memory_order_acquire) &
> +		RTE_MEMPOOL_F_POOL_CREATED) != 0;
> +}

mempool_is_created() should be public as rte_mempool_is_created().
Then the rte_mempool_walk() description can refer to it instead of referring to the RTE_MEMPOOL_F_POOL_CREATED flag.

The "Acquire:" comment is an implementation detail; when you make the function public, move that comment away from the function description and into the implementation instead.

About the function name:
When the empty mempool is created, it is assigned the "ring" driver as default.
Until the pool has been populated, it may be assigned a different mempool driver, e.g. the "stack" driver.
I suppose this is why the flag is named CREATED and not POPULATED.
And thus, the name rte_mempool_is_created() remains correct, rather than using a different name.
You may consider this information, if you choose to update the function description.

Notes:
Although the function is short and simple, it is not fast path, so it should remain non-inline.
You already made it non-inline, so I'm just making sure you keep it that way. :-)

It is used by mempool dump, so I don't think it can be marked experimental.

[...]

>   * The mempool list is locked while the iterator function runs, so the
>   * iterator function must not create or free a mempool.
>   *
> + * The iterator function is also called for mempools that are not
> + * populated yet, which do not have RTE_MEMPOOL_F_POOL_CREATED set in
> + * their flags. Such a mempool has no store yet, so the iterator
> function
> + * must check this flag before calling functions that query the

Remember referring to the new rte_mempool_is_created() function in this description.

> mempool
> + * driver, such as rte_mempool_avail_count().
> + *
>   * @param func
>   *   Iterator function
>   * @param arg

With the suggested change,
Acked-by: Morten Brørup <mb@smartsharesystems.com>