The patch titled
Subject: kernel/watchdog: provide watchdog_nmi_reconfigure() for arch watchdogs
has been removed from the -mm tree. Its filename was
watchdog-provide-watchdog_reconfigure-for-arch-watchdogs.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Nicholas Piggin <npiggin@xxxxxxxxx>
Subject: kernel/watchdog: provide watchdog_nmi_reconfigure() for arch watchdogs
After reconfiguring watchdog sysctls etc., architecture specific watchdogs
may not get all their parameters updated.
watchdog_nmi_reconfigure() can be implemented to pull the new values in
and set the arch NMI watchdog.
[npiggin@xxxxxxxxx: add code comments]
Link: http://lkml.kernel.org/r/20170617125933.774d3858@xxxxxxxxxxxxxxxxxxx
[arnd@xxxxxxxx: hide unused function]
Link: http://lkml.kernel.org/r/20170620204854.966601-1-arnd@xxxxxxxx
Link: http://lkml.kernel.org/r/20170616065715.18390-5-npiggin@xxxxxxxxx
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Don Zickus <dzickus@xxxxxxxxxx>
Tested-by: Babu Moger <babu.moger@xxxxxxxxxx> [sparc]
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/watchdog.c | 48 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 44 insertions(+), 4 deletions(-)
diff -puN kernel/watchdog.c~watchdog-provide-watchdog_reconfigure-for-arch-watchdogs kernel/watchdog.c
--- a/kernel/watchdog.c~watchdog-provide-watchdog_reconfigure-for-arch-watchdogs
+++ a/kernel/watchdog.c
@@ -114,6 +114,10 @@ int __read_mostly watchdog_suspended;
/*
* These functions can be overridden if an architecture implements its
* own hardlockup detector.
+ *
+ * watchdog_nmi_enable/disable can be implemented to start and stop when
+ * softlockup watchdog threads start and stop. The arch must select the
+ * SOFTLOCKUP_DETECTOR Kconfig.
*/
int __weak watchdog_nmi_enable(unsigned int cpu)
{
@@ -123,6 +127,22 @@ void __weak watchdog_nmi_disable(unsigne
{
}
+/*
+ * watchdog_nmi_reconfigure can be implemented to be notified after any
+ * watchdog configuration change. The arch hardlockup watchdog should
+ * respond to the following variables:
+ * - nmi_watchdog_enabled
+ * - watchdog_thresh
+ * - watchdog_cpumask
+ * - sysctl_hardlockup_all_cpu_backtrace
+ * - hardlockup_panic
+ * - watchdog_suspended
+ */
+void __weak watchdog_nmi_reconfigure(void)
+{
+}
+
+
#ifdef CONFIG_SOFTLOCKUP_DETECTOR
/* Helper for online, unparked cpus. */
@@ -600,6 +620,14 @@ static void watchdog_disable_all_cpus(vo
}
}
+#ifdef CONFIG_SYSCTL
+static int watchdog_update_cpus(void)
+{
+ return smpboot_update_cpumask_percpu_thread(
+ &watchdog_threads, &watchdog_cpumask);
+}
+#endif
+
#else /* SOFTLOCKUP */
static int watchdog_park_threads(void)
{
@@ -619,6 +647,13 @@ static void watchdog_disable_all_cpus(vo
{
}
+#ifdef CONFIG_SYSCTL
+static int watchdog_update_cpus(void)
+{
+ return 0;
+}
+#endif
+
static void set_sample_period(void)
{
}
@@ -651,6 +686,8 @@ int lockup_detector_suspend(void)
watchdog_enabled = 0;
}
+ watchdog_nmi_reconfigure();
+
mutex_unlock(&watchdog_proc_mutex);
return ret;
@@ -671,6 +708,8 @@ void lockup_detector_resume(void)
if (watchdog_running && !watchdog_suspended)
watchdog_unpark_threads();
+ watchdog_nmi_reconfigure();
+
mutex_unlock(&watchdog_proc_mutex);
put_online_cpus();
}
@@ -696,6 +735,8 @@ static int proc_watchdog_update(void)
else
watchdog_disable_all_cpus();
+ watchdog_nmi_reconfigure();
+
return err;
}
@@ -881,12 +922,11 @@ int proc_watchdog_cpumask(struct ctl_tab
* 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);
_
Patches currently in -mm which might be from npiggin@xxxxxxxxx are
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