On Fri, Mar 17, 2023 at 01:19:42PM -0700, Tyler Retzlaff wrote:
> Replace the use of rte_atomic.h types and functions, instead use GCC
> supplied C++11 memory model builtins.
>
> Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
> ---
> lib/ring/rte_ring_core.h | 1 -
> lib/ring/rte_ring_generic_pvt.h | 10 ++++++----
> 2 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/lib/ring/rte_ring_core.h b/lib/ring/rte_ring_core.h
> index 82b2370..b9c7860 100644
> --- a/lib/ring/rte_ring_core.h
> +++ b/lib/ring/rte_ring_core.h
> @@ -31,7 +31,6 @@
> #include <rte_config.h>
> #include <rte_memory.h>
> #include <rte_lcore.h>
> -#include <rte_atomic.h>
> #include <rte_branch_prediction.h>
> #include <rte_memzone.h>
> #include <rte_pause.h>
> diff --git a/lib/ring/rte_ring_generic_pvt.h b/lib/ring/rte_ring_generic_pvt.h
> index 5acb6e5..f9a15b6 100644
> --- a/lib/ring/rte_ring_generic_pvt.h
> +++ b/lib/ring/rte_ring_generic_pvt.h
> @@ -92,8 +92,9 @@
> if (is_sp)
> r->prod.head = *new_head, success = 1;
> else
> - success = rte_atomic32_cmpset(&r->prod.head,
> - *old_head, *new_head);
> + success = __atomic_compare_exchange_n(&r->prod.head,
> + old_head, *new_head, 0,
> + __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
> } while (unlikely(success == 0));
> return n;
> }
> @@ -162,8 +163,9 @@
> rte_smp_rmb();
> success = 1;
> } else {
> - success = rte_atomic32_cmpset(&r->cons.head, *old_head,
> - *new_head);
> + success = __atomic_compare_exchange_n(&r->cons.head,
> + old_head, *new_head, 0,
> + __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
> }
> } while (unlikely(success == 0));
> return n;
just something i noticed and not related to this change.
i note that old_head for both __rte_ring_move_prod_head and
__rte_ring_move_con_head are performing a non-atomic load to
initialize `*old_head` probably not the best idea.
