On Sat, Jul 05, 2014 at 10:44:41PM +0530, pawandeep oza wrote:
> process calls sys_reboot and that process then stops other CPUs while those
> CPUs are within a spin_lock() region we can potentially encounter a
> deadlock
> scenario like below.
>
> CPU 0 CPU 1
> ----- -----
> spin_lock(my_lock)
> smp_send_stop()
> <send IPI> handle_IPI()
> disable_preemption/irqs
> while(1);
> <PREEMPT>
> spin_lock(my_lock) <--- Waits forever
Please explain how that <PREEMPT> occurs with IRQs already disabled.
--
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