Re: [PATCH] x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt

From: Thomas Gleixner
Date: Wed Oct 12 2016 - 09:20:30 EST

On Wed, 12 Oct 2016, Wanpeng Li wrote:
> irq_enter() which is called in scheduler_ipi() is too late to tell RCU
> susbstems to end the extended quiescent state before ack_APIC_irq(),
> any ideas?

You can call irq_enter/exit() in __smp_reschedule_interrupt(). It can be
called nested.