[PATCH] check nmi watchdog is broken

A bug against an xSeries system showed up recently noting that the
check_nmi_watchdog() test was failing.

I have been investigating it and discovered in both i386 and x86_64 the
recent change to the routine to use the cpu_callin_map has uncovered a
problem.  Prior to that change, on an SMP box, the test was trivally
passing because all cpu's were found to not yet be online, but now with the
callin_map they are discovered, it goes on to test the counter and they
have not yet begun to increment, so it announces a CPU is stuck and bails
out.

On all the systems I have access to test, the announcement of failure is
also bougs...  by the time you can login and check /proc/interrupts, the
NMI count is happily incrementing on all CPUs.  Its just that the test is
being done too early.

I have tried moving the call to the test around a bit, and it was always
too early.  I finally hit on this proposed solution, it delays the routine
via a late_initcall(), seems like the right solution to me.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 0 insertions, 2 deletions

diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
index e1de67483f38..a5810cf7b578 100644
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -109,7 +109,6 @@ extern int APIC_init_uniprocessor (void);
 extern void disable_APIC_timer(void);
 extern void enable_APIC_timer(void);
 
-extern int check_nmi_watchdog (void);
 extern void enable_NMI_through_LVT0 (void * dummy);
 
 extern unsigned int nmi_watchdog;
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index c025cc3ef789..e4b1017b8b2b 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -99,7 +99,6 @@ extern void disable_APIC_timer(void);
 extern void enable_APIC_timer(void);
 extern void clustered_apic_check(void);
 
-extern int check_nmi_watchdog(void);
 extern void nmi_watchdog_default(void);
 extern int setup_nmi_watchdog(char *);