[RFC,15/23] kernel/watchdog: Add a function to obtain the watchdog_allowed_mask

Message ID 1528851463-21140-16-git-send-email-ricardo.neri-calderon@linux.intel.com
State Not Applicable
Delegated to: David Miller
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  • Implement an HPET-based hardlockup detector
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Commit Message

Ricardo Neri June 13, 2018, 12:57 a.m.
Implementations of NMI watchdogs that use a single piece of hardware to
monitor all the CPUs in the system (as opposed to per-CPU implementations
such as perf) need to know which CPUs the watchdog is allowed to monitor.
In this manner, non-maskable interrupts are directed only to the monitored

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Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
 include/linux/nmi.h | 1 +
 kernel/watchdog.c   | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)


diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index e61b441..e608762 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -77,6 +77,7 @@  static inline void reset_hung_task_detector(void) { }
 extern void hardlockup_detector_disable(void);
+extern struct cpumask *watchdog_get_allowed_cpumask(void);
 extern unsigned int hardlockup_panic;
 static inline void hardlockup_detector_disable(void) {}
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 5057376..b94bbe3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -50,7 +50,7 @@  int __read_mostly nmi_watchdog_available;
 static struct nmi_watchdog_ops *nmi_wd_ops;
-struct cpumask watchdog_allowed_mask __read_mostly;
+static struct cpumask watchdog_allowed_mask __read_mostly;
 struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -98,6 +98,11 @@  static int __init hardlockup_all_cpu_backtrace_setup(char *str)
 __setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
 # endif /* CONFIG_SMP */
+struct cpumask *watchdog_get_allowed_cpumask(void)
+	return &watchdog_allowed_mask;