RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE requirements

RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE requirements

[Morten Brørup]

Looking at rte_pktmbuf_prefree_seg() [1], the list of described requirements for RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE [2] seems incomplete. The following two requirements are missing:
- The mbufs must be direct.
- The mbufs must be non-segmented.

[1] https://elixir.bootlin.com/dpdk/latest/source/lib/mbuf/rte_mbuf.h#L1308
[2] https://elixir.bootlin.com/dpdk/latest/source/lib/ethdev/rte_ethdev.h#L1701


Med venlig hilsen / Kind regards,
-Morten Brørup

Re: RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE requirements

[Olivier Matz]

Hi Morten,

Yes, you are right. These 2 conditions are also needed if one wants to use
rte_mbuf_raw_free() or rte_mempool_put*() functions to free the mbufs.

Olivier

On Thu, Jul 14, 2022 at 12:46:24PM +0200, Morten Brørup wrote:
> Looking at rte_pktmbuf_prefree_seg() [1], the list of described requirements for RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE [2] seems incomplete. The following two requirements are missing:
> - The mbufs must be direct.
> - The mbufs must be non-segmented.
> 
> [1] https://elixir.bootlin.com/dpdk/latest/source/lib/mbuf/rte_mbuf.h#L1308
> [2] https://elixir.bootlin.com/dpdk/latest/source/lib/ethdev/rte_ethdev.h#L1701
> 
> 
> Med venlig hilsen / Kind regards,
> -Morten Brørup
>