[dpdk-dev] [RFC PATCH v3 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration

[Ananyev, Konstantin]

> 
> Signed-off-by: Feifei Wang <feifei.wang2 at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> ---
>  lib/bpf/bpf_pkt.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/bpf/bpf_pkt.c b/lib/bpf/bpf_pkt.c
> index 6e8248f0d6..3af15ae97b 100644
> --- a/lib/bpf/bpf_pkt.c
> +++ b/lib/bpf/bpf_pkt.c
> @@ -113,7 +113,7 @@ bpf_eth_cbi_unuse(struct bpf_eth_cbi *cbi)
>  static void
>  bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
>  {
> -	uint32_t nuse, puse;
> +	uint32_t puse;
> 
>  	/* make sure all previous loads and stores are completed */
>  	rte_smp_mb();
> @@ -122,11 +122,8 @@ bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
> 
>  	/* in use, busy wait till current RX/TX iteration is finished */
>  	if ((puse & BPF_ETH_CBI_INUSE) != 0) {
> -		do {
> -			rte_pause();
> -			rte_compiler_barrier();
> -			nuse = cbi->use;
> -		} while (nuse == puse);
> +		rte_compiler_barrier();
> +		rte_wait_event_32(&cbi->use, UINT_MAX, puse, ==, __ATOMIC_RELAXED);

If we do use atomic load, while we still need a compiler_barrier() here?

>  	}
>  }
> 
> --
> 2.25.1