xen/sched: disable scheduling when entering ACPI deep sleep states
When entering deep sleep states all domains are paused resulting in
all cpus only running idle vcpus. This enables us to stop scheduling
completely in order to avoid synchronization problems with core
scheduling when individual cpus are offlined.
Disabling the scheduler is done by replacing the softirq handler
with a dummy scheduling routine only enabling tasklets to run.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>