Re: [dpdk-dev] [PATCH v2 2/4] mempool: add non-IO flag

[Thomas Monjalon <thomas@monjalon.net>]

29/09/2021 16:52, dkozlyuk@oss.nvidia.com:
> From: Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com>
> 
> Mempool is a generic allocator that is not necessarily used for device
> IO operations and its memory for DMA. Add MEMPOOL_F_NON_IO flag to mark
> such mempools.
> 
> Signed-off-by: Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com>
> Acked-by: Matan Azrad <matan@nvidia.com>
> ---
>  doc/guides/rel_notes/release_21_11.rst | 3 +++
>  lib/mempool/rte_mempool.h              | 4 ++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
> index f85dc99c8b..873beda633 100644
> --- a/doc/guides/rel_notes/release_21_11.rst
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -155,6 +155,9 @@ API Changes
> +* mempool: Added ``MEMPOOL_F_NON_IO`` flag to give a hint to DPDK components
> +  that objects from this pool will not be used for device IO (e.g. DMA).

This is not a breaking change, but I am OK to add this note.
Any other opinion?

> +#define MEMPOOL_F_NON_IO         0x0040 /**< Not used for device IO (DMA). */

> + *   - MEMPOOL_F_NO_IO: If set, the mempool is considered to be
> + *     never used for device IO, i.e. DMA operations,
> + *     which may affect some PMD behavior.

Not limited to PMD, it may affect some libs.
I would reword the last line like this:
"No impact on mempool behaviour, but it is a hint for other components."