>
> First, fix the bug that keyword const of func arg should be after "*".
I believe there is no bug here.
> This is because const before "*" means the value of "cbi" should not be
> changed.
Exactly, it says that the function itself will not change the value of "cbi".
It just waits for the value to be changed by someone else.
So please keep parameter list intact.
> But we should monitor that cbi->use changed and then we can
> jump out of loop.
>
> Second, instead of polling for cbi->use to be updated, use
> wait event scheme.
>
> Fixes: a93ff62a8938 ("bpf: introduce basic Rx/Tx filters")
> Cc: konstantin.anan...@intel.com
> Cc: sta...@dpdk.org
>
> Signed-off-by: Feifei Wang <feifei.wa...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> ---
> lib/bpf/bpf_pkt.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/lib/bpf/bpf_pkt.c b/lib/bpf/bpf_pkt.c
> index 6e8248f0d6..08ed8ff68c 100644
> --- a/lib/bpf/bpf_pkt.c
> +++ b/lib/bpf/bpf_pkt.c
> @@ -111,9 +111,9 @@ bpf_eth_cbi_unuse(struct bpf_eth_cbi *cbi)
> * Waits till datapath finished using given callback.
> */
> static void
> -bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
> +bpf_eth_cbi_wait(struct bpf_eth_cbi *const 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);
> }
> }
>
> --
> 2.25.1
