nmi_watchdog: Config option to enable new nmi_watchdog

These are the bits that enable the new nmi_watchdog and safely
isolate the old nmi_watchdog.  Only one or the other can run,
not both at the same time.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: gorcunov@gmail.com
Cc: aris@redhat.com
Cc: peterz@infradead.org
LKML-Reference: <1265424425-31562-4-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile
index 565c1bfc507d..1a4512e48d24 100644
--- a/arch/x86/kernel/apic/Makefile
+++ b/arch/x86/kernel/apic/Makefile
@@ -2,7 +2,12 @@
 # Makefile for local APIC drivers and for the IO-APIC code
 #
 
-obj-$(CONFIG_X86_LOCAL_APIC)    += apic.o apic_noop.o probe_$(BITS).o ipi.o nmi.o
+obj-$(CONFIG_X86_LOCAL_APIC)    += apic.o apic_noop.o probe_$(BITS).o ipi.o
+ifneq ($(CONFIG_NMI_WATCHDOG),y)
+obj-$(CONFIG_X86_LOCAL_APIC)    += nmi.o
+endif
+obj-$(CONFIG_NMI_WATCHDOG)      += hw_nmi.o
+
 obj-$(CONFIG_X86_IO_APIC)       += io_apic.o
 obj-$(CONFIG_SMP)               += ipi.o
 
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 51ef893ffa65..973cbc4f044f 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -406,6 +406,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                                                         == NOTIFY_STOP)
                         return;
 
+#ifndef CONFIG_NMI_WATCHDOG
                 /*
                  * Ok, so this is none of the documented NMI sources,
                  * so it must be the NMI watchdog.
@@ -413,6 +414,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                 if (nmi_watchdog_tick(regs, reason))
                         return;
                 if (!do_nmi_callback(regs, cpu))
+#endif /* !CONFIG_NMI_WATCHDOG */
                         unknown_nmi_error(reason, regs);
 #else
                 unknown_nmi_error(reason, regs);