On Sun, Apr 26, 2020 at 2:09 PM Gavin Hu <gavin...@arm.com> wrote:
>
> In acquiring a spinlock, cores repeatedly poll the lock variable.
> This is replaced by rte_wait_until_equal API.
>
> Running the micro benchmarking and the testpmd and l3fwd traffic tests
> on ThunderX2, Ampere eMAG80 and Arm N1SDP, everything went well and no
> notable performance gain nor degradation was measured.
>
> Signed-off-by: Gavin Hu <gavin...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> Reviewed-by: Phil Yang <phil.y...@arm.com>
> Reviewed-by: Steve Capper <steve.cap...@arm.com>
> Reviewed-by: Ola Liljedahl <ola.liljed...@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> Tested-by: Pavan Nikhilesh <pbhagavat...@marvell.com>
Acked-by: Jerin Jacob <jer...@marvell.com>
> ---
> lib/librte_eal/include/generic/rte_spinlock.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_eal/include/generic/rte_spinlock.h
> b/lib/librte_eal/include/generic/rte_spinlock.h
> index 87ae7a4f1..40fe49d5a 100644
> --- a/lib/librte_eal/include/generic/rte_spinlock.h
> +++ b/lib/librte_eal/include/generic/rte_spinlock.h
> @@ -65,8 +65,8 @@ rte_spinlock_lock(rte_spinlock_t *sl)
>
> while (!__atomic_compare_exchange_n(&sl->locked, &exp, 1, 0,
> __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
> - while (__atomic_load_n(&sl->locked, __ATOMIC_RELAXED))
> - rte_pause();
> + rte_wait_until_equal_32((volatile uint32_t *)&sl->locked,
> + 0, __ATOMIC_RELAXED);
> exp = 0;
> }
> }
> --
> 2.17.1
>
