[PATCH] x86_64: make touch_nmi_watchdog() not touch impossible cpus' private data
Along with that, also suppress the memory touching altogether when the
watchdog is not running, to eliminate needless crosstalk. Plus ad a call
to it to make things consistent (one could also consider removing the call
in enable_timer_nmi_watchdog()).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 8be407a..5bf17e4 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -236,6 +236,7 @@
{
if (nmi_active < 0) {
nmi_watchdog = NMI_LOCAL_APIC;
+ touch_nmi_watchdog();
setup_apic_nmi_watchdog();
}
}
@@ -456,15 +457,17 @@
void touch_nmi_watchdog (void)
{
- int i;
+ if (nmi_watchdog > 0) {
+ unsigned cpu;
- /*
- * Tell other CPUs to reset their alert counters. We cannot
- * do it ourselves because the alert count increase is not
- * atomic.
- */
- for (i = 0; i < NR_CPUS; i++)
- per_cpu(nmi_touch, i) = 1;
+ /*
+ * Tell other CPUs to reset their alert counters. We cannot
+ * do it ourselves because the alert count increase is not
+ * atomic.
+ */
+ for_each_present_cpu (cpu)
+ per_cpu(nmi_touch, cpu) = 1;
+ }
touch_softlockup_watchdog();
}
