Re: [dpdk-dev] [PATCH v4 2/4] mempool: add non-IO flag

[David Marchand <david.marchand@redhat.com>]

Hello Dmitry,

On Wed, Oct 13, 2021 at 1:02 PM Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com> wrote:
> diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
> index 663123042f..029b62a650 100644
> --- a/lib/mempool/rte_mempool.h
> +++ b/lib/mempool/rte_mempool.h
> @@ -262,6 +262,8 @@ struct rte_mempool {
>  #define MEMPOOL_F_SC_GET         0x0008 /**< Default get is "single-consumer".*/
>  #define MEMPOOL_F_POOL_CREATED   0x0010 /**< Internal: pool is created. */
>  #define MEMPOOL_F_NO_IOVA_CONTIG 0x0020 /**< Don't need IOVA contiguous objs. */
> +#define MEMPOOL_F_NON_IO         0x0040
> +               /**< Internal: pool is not usable for device IO (DMA). */
>
>  /**
>   * @internal When debug is enabled, store some statistics.
> @@ -991,6 +993,9 @@ typedef void (rte_mempool_ctor_t)(struct rte_mempool *, void *);
>   *     "single-consumer". Otherwise, it is "multi-consumers".
>   *   - MEMPOOL_F_NO_IOVA_CONTIG: If set, allocated objects won't
>   *     necessarily be contiguous in IO memory.
> + *   - MEMPOOL_F_NON_IO: If set, the mempool is considered to be
> + *     never used for device IO, i.e. for DMA operations.
> + *     It's a hint to other components and does not affect the mempool behavior.
>   * @return
>   *   The pointer to the new allocated mempool, on success. NULL on error
>   *   with rte_errno set appropriately. Possible rte_errno values include:

- When rebasing on main, you probably won't be able to call this new flag.
The diff should be something like:

diff --git a/app/test/test_mempool.c b/app/test/test_mempool.c
index d886f4800c..35c80291fa 100644
--- a/app/test/test_mempool.c
+++ b/app/test/test_mempool.c
@@ -214,7 +214,7 @@ static int test_mempool_creation_with_unknown_flag(void)
                MEMPOOL_ELT_SIZE, 0, 0,
                NULL, NULL,
                NULL, NULL,
-               SOCKET_ID_ANY, MEMPOOL_F_NO_IOVA_CONTIG << 1);
+               SOCKET_ID_ANY, MEMPOOL_F_NON_IO << 1);

        if (mp_cov != NULL) {
                rte_mempool_free(mp_cov);
diff --git a/lib/mempool/rte_mempool.c b/lib/mempool/rte_mempool.c
index 8d5f99f7e7..27d197fe86 100644
--- a/lib/mempool/rte_mempool.c
+++ b/lib/mempool/rte_mempool.c
@@ -802,6 +802,7 @@ rte_mempool_cache_free(struct rte_mempool_cache *cache)
        | MEMPOOL_F_SC_GET \
        | MEMPOOL_F_POOL_CREATED \
        | MEMPOOL_F_NO_IOVA_CONTIG \
+       | MEMPOOL_F_NON_IO \
        )
 /* create an empty mempool */
 struct rte_mempool *


- While grepping, I noticed that proc-info also dumps mempool flags.
This could be something to enhance, maybe amending current
rte_mempool_dump() and having this tool use it.
But for now, can you update this tool too?


-- 
David Marchand