Re: [dpdk-dev] [PATCH v3 9/9] mempool/bucket: handle non-EAL lcores

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 6/22/20 4:25 PM, David Marchand wrote:
> Convert to new lcore API to support non-EAL lcores.
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>  drivers/mempool/bucket/rte_mempool_bucket.c | 131 ++++++++++++--------
>  1 file changed, 82 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/mempool/bucket/rte_mempool_bucket.c b/drivers/mempool/bucket/rte_mempool_bucket.c
> index 5ce1ef16fb..0b4f42d330 100644
> --- a/drivers/mempool/bucket/rte_mempool_bucket.c
> +++ b/drivers/mempool/bucket/rte_mempool_bucket.c
> @@ -55,6 +55,7 @@ struct bucket_data {
>  	struct rte_ring *shared_orphan_ring;
>  	struct rte_mempool *pool;
>  	unsigned int bucket_mem_size;
> +	void *lcore_callback_handle;
>  };
>  
>  static struct bucket_stack *
> @@ -345,6 +346,22 @@ bucket_dequeue_contig_blocks(struct rte_mempool *mp, void **first_obj_table,
>  	return 0;
>  }
>  
> +struct bucket_per_lcore_ctx {

The structure is not used in per-lcore init and uninit
functions. So, it is better to add _count to make it
count specified. I.e. bucket_count_per_lcore_ctx.

> +	const struct bucket_data *bd;
> +	unsigned int count;
> +};
> +
> +static int
> +count_per_lcore(unsigned int lcore_id, void *arg)
> +{
> +	struct bucket_per_lcore_ctx *ctx = arg;
> +
> +	ctx->count += ctx->bd->obj_per_bucket *
> +		ctx->bd->buckets[lcore_id]->top;
> +	ctx->count += rte_ring_count(ctx->bd->adoption_buffer_rings[lcore_id]);
> +	return 0;
> +}
> +
>  static void
>  count_underfilled_buckets(struct rte_mempool *mp,
>  			  void *opaque,
> @@ -373,23 +390,66 @@ count_underfilled_buckets(struct rte_mempool *mp,
>  static unsigned int
>  bucket_get_count(const struct rte_mempool *mp)
>  {
> -	const struct bucket_data *bd = mp->pool_data;
> -	unsigned int count =
> -		bd->obj_per_bucket * rte_ring_count(bd->shared_bucket_ring) +
> -		rte_ring_count(bd->shared_orphan_ring);
> -	unsigned int i;
> +	struct bucket_per_lcore_ctx ctx;

Just a nit, but I think that ctx is too generic.
(some time ago bucket_data bd was ctx in fact :) )
May be bplc? Up to you.

>  
> -	for (i = 0; i < RTE_MAX_LCORE; i++) {
> -		if (!rte_lcore_is_enabled(i))
> -			continue;
> -		count += bd->obj_per_bucket * bd->buckets[i]->top +
> -			rte_ring_count(bd->adoption_buffer_rings[i]);
> -	}
> +	ctx.bd = mp->pool_data;
> +	ctx.count = ctx.bd->obj_per_bucket *
> +		rte_ring_count(ctx.bd->shared_bucket_ring);
> +	ctx.count += rte_ring_count(ctx.bd->shared_orphan_ring);
>  
> +	rte_lcore_iterate(count_per_lcore, &ctx);
>  	rte_mempool_mem_iter((struct rte_mempool *)(uintptr_t)mp,
> -			     count_underfilled_buckets, &count);
> +			     count_underfilled_buckets, &ctx.count);
> +
> +	return ctx.count;
> +}
> +
> +static int
> +bucket_init_per_lcore(unsigned int lcore_id, void *arg)

It should be no bucket_ prefix here, or it should be bucket_
prefix above in count_per_lcore.

> +{
> +	char rg_name[RTE_RING_NAMESIZE];
> +	struct bucket_data *bd = arg;
> +	struct rte_mempool *mp;
> +	int rg_flags;
> +	int rc;
> +
> +	mp = bd->pool;
> +	bd->buckets[lcore_id] = bucket_stack_create(mp,
> +		mp->size / bd->obj_per_bucket);
> +	if (bd->buckets[lcore_id] == NULL)
> +		goto error;
> +
> +	rc = snprintf(rg_name, sizeof(rg_name), RTE_MEMPOOL_MZ_FORMAT ".a%u",
> +		mp->name, lcore_id);
> +	if (rc < 0 || rc >= (int)sizeof(rg_name))
> +		goto error;
> +
> +	rg_flags = RING_F_SC_DEQ;
> +	if (mp->flags & MEMPOOL_F_SP_PUT)
> +		rg_flags |= RING_F_SP_ENQ;
> +	if (mp->flags & MEMPOOL_F_SC_GET)
> +		rg_flags |= RING_F_SC_DEQ;

There is not point to have two above lines here, since
RING_F_SC_DEQ is always set.

> +	bd->adoption_buffer_rings[lcore_id] = rte_ring_create(rg_name,
> +		rte_align32pow2(mp->size + 1), mp->socket_id, rg_flags);
> +	if (bd->adoption_buffer_rings[lcore_id] == NULL)
> +		goto error;
>  
> -	return count;
> +	return 0;
> +error:
> +	rte_free(bd->buckets[lcore_id]);
> +	bd->buckets[lcore_id] = NULL;
> +	return -1;

Why does the API collapse all negative errnos into -1?
(I don't think it is critical, just want to know why).

> +}
> +
> +static void
> +bucket_uninit_per_lcore(unsigned int lcore_id, void *arg)

Same note about bucket_ prefix.