powerpc/cpuidle: Fixes for pseries_idle hotplug notifier
Currently the call to pseries_notify_cpuidle_add_cpu(), that takes action on the cpuidle front when a cpu is added/removed is being made from smp_xics_setup_cpu(). This caused lockdep issues as reported https://lkml.org/lkml/2012/5/17/2 On addition of each cpu, resources were cleared and re-allocated each time, all in critical section as part of start_secondary() call were interrupts are disabled. To resolve this issue, the pseries_notify_cpuidle_add_cpu() call is is being replaced by a hotplug notifier which would prevent cpuidle resources from being released and allocated each time cpu is onlined in the critical code path. It was fixed in https://lkml.org/lkml/2012/5/18/174. Also it is essential to call cpuidle_enable/disable_device between cpuidle_pause_and_lock() and cpuidle_resume_and_unlock() when used externally to avoid race conditions. Add support for CPU_ONLINE_FROZEN and CPU_DEAD_FROZEN as part of hotplug notify event for pseries_idle and unregister hotplug notifier while exiting out. The above mentioned issues are fixed as part of this patch. Signed-off-by:Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org>
parent
8bf8385b
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