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authorDon Zickus <dzickus@redhat.com>2010-08-31 23:00:07 -0400
committerIngo Molnar <mingo@elte.hu>2010-09-01 10:02:28 +0200
commit68d3f1d810500e8b975bdf0b20dd83d060076b4b (patch)
tree68d07e9d165aa9fde390dfa5694bb58aa63adb0d /kernel
parent3aaba20f26f58843e8f20611e5c0b1c06954310f (diff)
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lockup_detector: Sync touch_*_watchdog back to old semantics
During my rewrite, the semantics of touch_nmi_watchdog and touch_softlockup_watchdog changed enough to break some drivers (mostly over preemptable regions). These are cases where long delays on one CPU (due to print_delay for example) can cause long delays on other CPUs - so we must 'touch' the nmi_watchdog flag of those other CPUs as well. This change brings those touch_*_watchdog() functions back in line with to how they used to work. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: peterz@infradead.org Cc: fweisbec@gmail.com LKML-Reference: <1283310009-22168-2-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/watchdog.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 0d53c8e853b..7f9c3c52ecc 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -122,7 +122,7 @@ static void __touch_watchdog(void)
void touch_softlockup_watchdog(void)
{
- __get_cpu_var(watchdog_touch_ts) = 0;
+ __raw_get_cpu_var(watchdog_touch_ts) = 0;
}
EXPORT_SYMBOL(touch_softlockup_watchdog);
@@ -142,7 +142,14 @@ void touch_all_softlockup_watchdogs(void)
#ifdef CONFIG_HARDLOCKUP_DETECTOR
void touch_nmi_watchdog(void)
{
- __get_cpu_var(watchdog_nmi_touch) = true;
+ if (watchdog_enabled) {
+ unsigned cpu;
+
+ for_each_present_cpu(cpu) {
+ if (per_cpu(watchdog_nmi_touch, cpu) != true)
+ per_cpu(watchdog_nmi_touch, cpu) = true;
+ }
+ }
touch_softlockup_watchdog();
}
EXPORT_SYMBOL(touch_nmi_watchdog);
@@ -433,6 +440,9 @@ static int watchdog_enable(int cpu)
wake_up_process(p);
}
+ /* if any cpu succeeds, watchdog is considered enabled for the system */
+ watchdog_enabled = 1;
+
return 0;
}
@@ -455,9 +465,6 @@ static void watchdog_disable(int cpu)
per_cpu(softlockup_watchdog, cpu) = NULL;
kthread_stop(p);
}
-
- /* if any cpu succeeds, watchdog is considered enabled for the system */
- watchdog_enabled = 1;
}
static void watchdog_enable_all_cpus(void)