The patch titled
lockup detector: sync touch_*_watchdog back to old semantics
has been added to the -mm tree. Its filename is
lockup-detector-sync-touch__watchdog-back-to-old-semantics.patch
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Subject: lockup detector: sync touch_*_watchdog back to old semantics
From: Don Zickus <dzickus@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Yong Zhang <yong.zhang0@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/watchdog.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff -puN kernel/watchdog.c~lockup-detector-sync-touch__watchdog-back-to-old-semantics kernel/watchdog.c
--- a/kernel/watchdog.c~lockup-detector-sync-touch__watchdog-back-to-old-semantics
+++ a/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)
_
Patches currently in -mm which might be from dzickus@xxxxxxxxxx are
origin.patch
linux-next.patch
lockup-detector-sync-touch__watchdog-back-to-old-semantics.patch
lockup_detector-convert-cpu-notifier-to-return-encapsulate-errno-value.patch
lockup_detector-remove-unnecessary-panic_notifier.patch
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