x86, NMI: Add knob to disable using NMI IPIs to stop cpus (bda62633) · Commits · 戴 / test

Some machines may exhibit problems using the NMI to stop other cpus. This knob just allows one to revert back to the original behaviour to help diagnose the problem. V2: make function static Signed-off-by:

Don Zickus <dzickus@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Richter <robert.richter@amd.com> Cc: seiji.aguchi@hds.com Cc: vgoyal@redhat.com Cc: mjg@redhat.com Cc: tony.luck@intel.com Cc: gong.chen@intel.com Cc: satoru.moriya@hds.com Cc: avi@redhat.com Cc: Andi Kleen <andi@firstfloor.org> Link: http://lkml.kernel.org/r/1318533267-18880-4-git-send-email-dzickus@redhat.com Signed-off-by:

Ingo Molnar <mingo@elte.hu>

Documentation/kernel-parameters.txt

+4 −0

Original line number	Diff line number	Diff line
		@@ -1796,6 +1796,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
		nomfgpt [X86-32] Disable Multi-Function General Purpose
		Timer usage (for AMD Geode machines).

		nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
		shutdown the other cpus. Instead use the REBOOT_VECTOR
		irq.

		nopat [X86] Disable PAT (page attribute table extension of
		pagetables) support.

arch/x86/kernel/smp.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -249,6 +249,11 @@ static void native_irq_stop_other_cpus(int wait)
		local_irq_restore(flags);
		}

		static void native_smp_disable_nmi_ipi(void)
		{
		smp_ops.stop_other_cpus = native_irq_stop_other_cpus;
		}

		/*
		* Reschedule call back.
		*/
		@@ -280,6 +285,14 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
		irq_exit();
		}

		static int __init nonmi_ipi_setup(char *str)
		{
		native_smp_disable_nmi_ipi();
		return 1;
		}

		__setup("nonmi_ipi", nonmi_ipi_setup);

		struct smp_ops smp_ops = {
		.smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
		.smp_prepare_cpus = native_smp_prepare_cpus,

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