ARM v8 rte_power_pause

[Morten Brørup]

Hi Wathsala, Hemant and Sachin,

Over at the Grout project, we are discussing power management in the context of 100 Gbit/s latency deadlines [1].

rte_power_pause() is not implemented for ARM v8 / Cortex-A72.
Syscalls such as nanosleep() have too much overhead, and cannot be used.

Any suggestions for a power-reducing method to make a CPU core "sleep" (i.e. do nothing) for durations in the order of 1 microsecond?

[1]: https://github.com/DPDK/grout/pull/624#issuecomment-4602036364

-Morten