Hi Hemant,
On Mon, 3 Apr 2017 14:42:09 +0530, Hemant Agrawal <hemant.agra...@nxp.com>
wrote:
> Hardware pools need to distinguish between buffers allocated using
> software or hardware backed pools.
>
> Some HW NICs may choose to autonomously free the pickets during
> transmit if the packet is from HW pool. While they should not do
> it for software backed pools.
>
> Such flag would also help when multiple pools are being handled by
> a PMD, saving costly compare operations for any internal marker.
>
> Signed-off-by: Hemant Agrawal <hemant.agra...@nxp.com>
> ---
> lib/librte_mempool/rte_mempool.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/lib/librte_mempool/rte_mempool.h
> b/lib/librte_mempool/rte_mempool.h
> index 991feaa..91dbd21 100644
> --- a/lib/librte_mempool/rte_mempool.h
> +++ b/lib/librte_mempool/rte_mempool.h
> @@ -263,6 +263,11 @@ 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_PHYS_CONTIG 0x0020 /**< Don't need physically
> contiguous objs. */
> +#define MEMPOOL_F_HW_POOL (1 << ((sizeof(int) * 8) - 1)) /**<
> Internal:
> + * Hardware offloaded pool. This information may be used by the
> + * NIC or other hw. Some NICs autonomously free the HW backed pool
> packets. */
> +
> +/**< Don't need physically contiguous objs. */
>
> /**
> * @internal When debug is enabled, store some statistics.
One thing is still not clear to me: in your driver, you check this flag:
- if it is unset, you reallocate a packet from your hw pool, you copy
some metadata, and you send it to the hw.
- if it is set, you assume that you can call mempool_to_bpid(mp) and directly
send it to the hw.
I think this is not correct. The test you want to do in your driver is:
"is it the pool that I registered for my hardware"?
It is not:
"is it a hardware managed pool?".
I think what you are doing here prevents to use 2 hardware mempools
at the same time, because they would all have this flag, and mempool_to_bpid()
would probably crash.
Instead, can't you just compare the mempool pointer to a value stored internally
in the driver?
Olivier
