On Wed, May 28, 2014 at 10:08:56AM +0530, Preeti U Murthy wrote:
> From: Srivatsa S. Bhat <[email protected]>
>
> The offline cpus are put to fast sleep if the idle state is discovered in the
> device tree. This is to gain maximum powersavings in the offline state.
...
> while (!generic_check_cpu_restart(cpu)) {
> ppc64_runlatch_off();
> - power7_nap();
> +
> + /* If sleep is supported, go to sleep, instead of nap */
> + if (idle_states & IDLE_USE_SLEEP)
> + power7_sleep();
> + else
> + power7_nap();
> +
> ppc64_runlatch_on();
> if (!generic_check_cpu_restart(cpu)) {
> DBG("CPU%d Unexpected exit while offline !\n", cpu);
What is the latency for waking up from fast sleep state? I'm concerned
this will increase the latency for entering KVM guests.
Paul.