[dpdk-dev] [PATCH v5 8/8] event/opdl: use new API to save cycles on aarch64

[Jerin Jacob]

On Thu, Sep 12, 2019 at 4:57 PM Gavin Hu <gavin.hu at arm.com> wrote:
>
> Use the new API to wait in low power state instead of continuous
> polling to save CPU cycles and power.
>
> Signed-off-by: Gavin Hu <gavin.hu at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>

Reviewed-by: Jerin Jacob <jerinj at marvell.com>


> ---
>  drivers/event/opdl/opdl_ring.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/event/opdl/opdl_ring.c b/drivers/event/opdl/opdl_ring.c
> index e8b29e2..f446fa3 100644
> --- a/drivers/event/opdl/opdl_ring.c
> +++ b/drivers/event/opdl/opdl_ring.c
> @@ -17,6 +17,7 @@
>  #include <rte_memory.h>
>  #include <rte_memzone.h>
>  #include <rte_eal_memconfig.h>
> +#include <rte_atomic.h>
>
>  #include "opdl_ring.h"
>  #include "opdl_log.h"
> @@ -475,9 +476,7 @@ opdl_ring_input_multithread(struct opdl_ring *t, const void *entries,
>         /* If another thread started inputting before this one, but hasn't
>          * finished, we need to wait for it to complete to update the tail.
>          */
> -       while (unlikely(__atomic_load_n(&s->shared.tail, __ATOMIC_ACQUIRE) !=
> -                       old_head))
> -               rte_pause();
> +       rte_wait_until_equal_acquire_32(&s->shared.tail, old_head);
>
>         __atomic_store_n(&s->shared.tail, old_head + num_entries,
>                         __ATOMIC_RELEASE);
> --
> 2.7.4
>