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Date: Wed, 12 Oct 2016 15:17:50 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Wanpeng Li <kernellwp@gmail.com>
cc: Peter Zijlstra <peterz@infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Wanpeng Li <wanpeng.li@hotmail.com>
Subject: Re: [PATCH] x86/apic: Fix suspicious RCU usage in
 smp_trace_call_function_interrupt
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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.

Thanks,

	tglx