> The rte_wait_until_equal_xx APIs abstract the functionality of
> 'polling for a memory location to become equal to a given value'.
>
> Add the RTE_ARM_USE_WFE configuration entry for aarch64, disabled
> by default. When it is enabled, the above APIs will call WFE instruction
> to save CPU cycles and power.
>
> From a VM, when calling this API on aarch64, it may trap in and out to
> release vCPUs whereas cause high exit latency. Since kernel 4.18.20 an
> adaptive trapping mechanism is introduced to balance the latency and
> workload.
>
> Signed-off-by: Gavin Hu <gavin...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@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>
> Reviewed-by: Phil Yang <phil.y...@arm.com>
> Acked-by: Pavan Nikhilesh <pbhagavat...@marvell.com>
> Acked-by: Jerin Jacob <jer...@marvell.com>
> ---
Acked-by: Konstantin Ananyev <konstantin.anan...@intel.com>
> 2.7.4
