x86, NMI: Add knob to disable using NMI IPIs to stop cpus
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>
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index e72b175..113acda 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -249,6 +249,11 @@
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 @@
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,