[PATCH 1/3] [lockup detector] sync touch_*_watchdog back to old semantics

Don Zickus
2010-09-01T03:00:46Z

During my rewrite, the semantics of touch_nmi_watchdog and
touch_softlockup_watchdog changed enough to break some drivers
(mostly over preemptable regions).

This change brings those touch_*_watchdog functions back in line
to how they used to work.

Signed-off-by: Don Zickus <dzickus@redhat.com>
---
kernel/watchdog.c | 17 ++++++++++++-----
1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 0d53c8e..7f9c3c5 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)
--
1.7.2.2