x86: fix NMI watchdog & 'stopped time' problem
More than 3 years ago Niclas Gustafsson reported a 'stopped time'
problem:
> Watching the /proc/interrupts with 10s apart after the "stop".
>
> [root@s151 root]# more /proc/interrupts
> CPU0
> 0: 66413955 local-APIC-edge timer
[...]
> LOC: 67355837
> ERR: 0
> MIS: 0
> [root@s151 root]# more /proc/interrupts
> CPU0
> 0: 66413955 local-APIC-edge timer
[...]
> LOC: 67379568
> ERR: 0
> MIS: 0
This may be because buggy SMM firmware messes with the 8259A (configured
for a transparent mode -- yes that rare "local-APIC-edge" mode is tricky
;-) ) insanely.
this should resolve:
http://bugzilla.kernel.org/show_bug.cgi?id=2544
http://bugzilla.kernel.org/show_bug.cgi?id=6296
Patch-dusted-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index 600fd40..f5cc47c 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -25,6 +25,7 @@
#include <asm/smp.h>
#include <asm/nmi.h>
+#include <asm/timer.h>
#include "mach_traps.h"
@@ -83,7 +84,7 @@
prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
if (!prev_nmi_count)
- return -1;
+ goto error;
printk(KERN_INFO "Testing NMI watchdog ... ");
@@ -117,7 +118,7 @@
if (!atomic_read(&nmi_active)) {
kfree(prev_nmi_count);
atomic_set(&nmi_active, -1);
- return -1;
+ goto error;
}
printk("OK.\n");
@@ -128,6 +129,10 @@
kfree(prev_nmi_count);
return 0;
+error:
+ timer_ack = !cpu_has_tsc;
+
+ return -1;
}
/* This needs to happen later in boot so counters are working */
late_initcall(check_nmi_watchdog);