[PATCH 4/5] watchdog: Provide watchdog_reconfigure() for arch watchdogs

Nicholas Piggin
2017-05-22T13:04:34Z

After reconfiguring watchdog sysctls etc., architecture specific
watchdogs may not get all their parameters updated.

watchdog_reconfigure() can be implemented to pull the new values
in and set the arch NMI watchdog.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
kernel/watchdog.c | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index deb010505646..d2996f5bf551 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -120,6 +120,11 @@ void __weak watchdog_nmi_disable(unsigned int cpu)
{
}

+void __weak watchdog_nmi_reconfigure(void)
+{
+}
+
+
#ifdef CONFIG_SOFTLOCKUP_DETECTOR

/* Helper for online, unparked cpus. */
@@ -597,6 +602,12 @@ static void watchdog_disable_all_cpus(void)
}
}

+static int watchdog_update_cpus(void)
+{
+ return smpboot_update_cpumask_percpu_thread(
+ &watchdog_threads, &watchdog_cpumask);
+}
+
#else /* SOFTLOCKUP */
static int watchdog_park_threads(void)
{
@@ -616,6 +627,10 @@ static void watchdog_disable_all_cpus(void)
{
}

+static int watchdog_update_cpus(void)
+{
+}
+
static void set_sample_period(void)
{
}
@@ -648,6 +663,8 @@ int lockup_detector_suspend(void)
watchdog_enabled = 0;
}

+ watchdog_nmi_reconfigure();
+
mutex_unlock(&watchdog_proc_mutex);

return ret;
@@ -668,6 +685,8 @@ void lockup_detector_resume(void)
if (watchdog_running && !watchdog_suspended)
watchdog_unpark_threads();

+ watchdog_nmi_reconfigure();
+
mutex_unlock(&watchdog_proc_mutex);
put_online_cpus();
}
@@ -693,6 +712,8 @@ static int proc_watchdog_update(void)
else
watchdog_disable_all_cpus();

+ watchdog_nmi_reconfigure();
+
return err;

}
@@ -878,12 +899,11 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write,
* a temporary cpumask, so we are likely not in a
* position to do much else to make things better.
*/
-#ifdef CONFIG_SOFTLOCKUP_DETECTOR
- if (smpboot_update_cpumask_percpu_thread(
- &watchdog_threads, &watchdog_cpumask) != 0)
+ if (watchdog_update_cpus() != 0)
pr_err("cpumask update failed\n");
-#endif
}
+
+ watchdog_nmi_reconfigure();
}
out:
mutex_unlock(&watchdog_proc_mutex);
--
2.11.0