[dpdk-dev] [RFC 3/4] mempool: introduce function to get mempool page size

[Andrew Rybchenko]

On 7/19/19 4:38 PM, Olivier Matz wrote:
> In rte_mempool_populate_default(), we determine the page size,
> which is needed for calc_size and allocation of memory.
> 
> Move this in a function and export it, it will be used in next
> commit.

The major change here is taking page sizes into account even in the
case of RTE_IOVA_VA. As I understand it is the main problem initially
that we should respect page boundaries even in RTE_IOVA_VA case.
It looks like we can have it even without removal of contiguous
allocation attempt.

> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> ---
>   lib/librte_mempool/rte_mempool.c | 50 +++++++++++++++++++++++++---------------
>   lib/librte_mempool/rte_mempool.h |  6 +++++
>   2 files changed, 37 insertions(+), 19 deletions(-)
> 
> diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
> index 335032dc8..7def0ba68 100644
> --- a/lib/librte_mempool/rte_mempool.c
> +++ b/lib/librte_mempool/rte_mempool.c
> @@ -414,6 +414,32 @@ rte_mempool_populate_virt(struct rte_mempool *mp, char *addr,
>   	return ret;
>   }
>   
> +int
> +rte_mempool_get_page_size(struct rte_mempool *mp, size_t *pg_sz)
> +{
> +	bool need_iova_contig_obj;
> +	bool alloc_in_ext_mem;
> +	int ret;
> +
> +	/* check if we can retrieve a valid socket ID */
> +	ret = rte_malloc_heap_socket_is_external(mp->socket_id);
> +	if (ret < 0)
> +		return -EINVAL;
> +	alloc_in_ext_mem = (ret == 1);
> +	need_iova_contig_obj = !(mp->flags & MEMPOOL_F_NO_IOVA_CONTIG);
> +
> +	if (!need_iova_contig_obj)
> +		*pg_sz = 0;
> +	else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA)
> +		*pg_sz = get_min_page_size(mp->socket_id);
> +	else if (rte_eal_has_hugepages() || alloc_in_ext_mem)
> +		*pg_sz = get_min_page_size(mp->socket_id);
> +	else
> +		*pg_sz = getpagesize();
> +
> +	return 0;
> +}
> +
>   /* Default function to populate the mempool: allocate memory in memzones,
>    * and populate them. Return the number of objects added, or a negative
>    * value on error.
> @@ -425,12 +451,11 @@ rte_mempool_populate_default(struct rte_mempool *mp)
>   	char mz_name[RTE_MEMZONE_NAMESIZE];
>   	const struct rte_memzone *mz;
>   	ssize_t mem_size;
> -	size_t align, pg_sz, pg_shift;
> +	size_t align, pg_sz, pg_shift = 0;
>   	rte_iova_t iova;
>   	unsigned mz_id, n;
>   	int ret;
>   	bool need_iova_contig_obj;
> -	bool alloc_in_ext_mem;
>   
>   	ret = mempool_ops_alloc_once(mp);
>   	if (ret != 0)
> @@ -482,26 +507,13 @@ rte_mempool_populate_default(struct rte_mempool *mp)
>   	 * synonymous with IOVA contiguousness will not hold.
>   	 */
>   
> -	/* check if we can retrieve a valid socket ID */
> -	ret = rte_malloc_heap_socket_is_external(mp->socket_id);
> -	if (ret < 0)
> -		return -EINVAL;
> -	alloc_in_ext_mem = (ret == 1);
>   	need_iova_contig_obj = !(mp->flags & MEMPOOL_F_NO_IOVA_CONTIG);
> +	ret = rte_mempool_get_page_size(mp, &pg_sz);
> +	if (ret < 0)
> +		return ret;
>   
> -	if (!need_iova_contig_obj) {
> -		pg_sz = 0;
> -		pg_shift = 0;
> -	} else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA) {
> -		pg_sz = 0;
> -		pg_shift = 0;
> -	} else if (rte_eal_has_hugepages() || alloc_in_ext_mem) {
> -		pg_sz = get_min_page_size(mp->socket_id);
> -		pg_shift = rte_bsf32(pg_sz);
> -	} else {
> -		pg_sz = getpagesize();
> +	if (pg_sz != 0)
>   		pg_shift = rte_bsf32(pg_sz);
> -	}
>   
>   	for (mz_id = 0, n = mp->size; n > 0; mz_id++, n -= ret) {
>   		size_t min_chunk_size;
> diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
> index 7bc10e699..00b927989 100644
> --- a/lib/librte_mempool/rte_mempool.h
> +++ b/lib/librte_mempool/rte_mempool.h
> @@ -1692,6 +1692,12 @@ uint32_t rte_mempool_calc_obj_size(uint32_t elt_size, uint32_t flags,
>   void rte_mempool_walk(void (*func)(struct rte_mempool *, void *arg),
>   		      void *arg);
>   
> +/**
> + * @internal Get page size used for mempool object allocation.
> + */
> +int
> +rte_mempool_get_page_size(struct rte_mempool *mp, size_t *pg_sz);
> +
>   #ifdef __cplusplus
>   }
>   #endif
>