[dpdk-dev] [PATCH v12 2/5] eal: add the APIs to wait until equal

[Ananyev, Konstantin]

> 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.hu at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> Reviewed-by: Steve Capper <steve.capper at arm.com>
> Reviewed-by: Ola Liljedahl <ola.liljedahl at arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> Reviewed-by: Phil Yang <phil.yang at arm.com>
> Acked-by: Pavan Nikhilesh <pbhagavatula at marvell.com>
> Acked-by: Jerin Jacob <jerinj at marvell.com>
> ---

Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>

> 2.7.4