Re: [PATCH dpdk v7] graph: expose node context as pointers

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

On Mon, Sep 30, 2024 at 11:28 AM Robin Jarry <rjarry@redhat.com> wrote:
>
> In some cases, the node context data is used to store two pointers
> because the data is larger than the reserved 16 bytes. Having to define
> intermediate structures just to be able to cast is tedious. And without
> intermediate structures, casting to opaque pointers is hard without
> violating strict aliasing rules.
>
> Add an unnamed union to allow storing opaque pointers in the node
> context. Unfortunately, aligning an unnamed union that contains an array
> produces inconsistent results between C and C++. To preserve ABI/API
> compatibility in both C and C++, move all fast-path area fields into an
> unnamed struct which is itself cache aligned. Use __rte_cache_aligned to
> preserve existing alignment on architectures where cache lines are 128
> bytes.
>
> Add a static assert to ensure that the fast path area does not grow
> beyond a 64 bytes cache line.
>
> Signed-off-by: Robin Jarry <rjarry@redhat.com>
> Acked-by: Kiran Kumar Kokkilagadda <kirankumark@marvell.com>

Applied, thanks.


-- 
David Marchand