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Commit 84e478c6 authored by Don Zickus's avatar Don Zickus Committed by Ingo Molnar
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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: default avatarDon 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: default avatarIngo Molnar <mingo@elte.hu>
parent 1fb9d6ad

arch/x86/kernel/apic/Makefile

+6 −1
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/traps.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/nmi.h

+4 −0
Original line number Diff line number Diff line
@@ -47,4 +47,8 @@ static inline bool trigger_all_cpu_backtrace(void) 
}

#endif



#ifdef CONFIG_NMI_WATCHDOG

int hw_nmi_is_cpu_stuck(struct pt_regs *);

#endif



#endif

kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -76,6 +76,7 @@ obj-$(CONFIG_AUDIT_TREE) += audit_tree.o 
obj-$(CONFIG_KPROBES) += kprobes.o

obj-$(CONFIG_KGDB) += kgdb.o

obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o

obj-$(CONFIG_NMI_WATCHDOG) += nmi_watchdog.o

obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o

obj-$(CONFIG_GENERIC_HARDIRQS) += irq/

obj-$(CONFIG_SECCOMP) += seccomp.o

lib/Kconfig.debug

+13 −0
Original line number Diff line number Diff line
@@ -170,6 +170,19 @@ config DETECT_SOFTLOCKUP 
	   can be detected via the NMI-watchdog, on platforms that

	   support it.)



config NMI_WATCHDOG

	bool "Detect Hard Lockups with an NMI Watchdog"

	depends on DEBUG_KERNEL && PERF_EVENTS

	default y

	help

	  Say Y here to enable the kernel to use the NMI as a watchdog

	  to detect hard lockups.  This is useful when a cpu hangs for no

	  reason but can still respond to NMIs.  A backtrace is displayed

	  for reviewing and reporting.



	  The overhead should be minimal, just an extra NMI every few

	  seconds.



config BOOTPARAM_SOFTLOCKUP_PANIC

	bool "Panic (Reboot) On Soft Lockups"

	depends on DETECT_SOFTLOCKUP