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authorUlrich Obergfell <uobergfe@redhat.com>2015-04-14 15:43:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:48:58 -0700
commita0c9cbb93da9b9a0e00907a4a5d2e5f1fed86350 (patch)
tree00fb4278d3c4716b9abcd9594fa493958691e069 /kernel/watchdog.c
parent84d56e66b9b4a646f04ec30696ca1aeea5e654d5 (diff)
watchdog: introduce the proc_watchdog_update() function
This series introduces a separate handler for each watchdog parameter in /proc/sys/kernel. The separate handlers need a common function that they can call to update the run state of the lockup detectors, or to have the lockup detectors use a new sample period. Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/watchdog.c')
-rw-r--r--kernel/watchdog.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9a1c78769a33..dcc4990097a2 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -679,6 +679,29 @@ static void watchdog_disable_all_cpus(void)
}
/*
+ * Update the run state of the lockup detectors.
+ */
+static int proc_watchdog_update(void)
+{
+ int err = 0;
+
+ /*
+ * Watchdog threads won't be started if they are already active.
+ * The 'watchdog_running' variable in watchdog_*_all_cpus() takes
+ * care of this. If those threads are already active, the sample
+ * period will be updated and the lockup detectors will be enabled
+ * or disabled 'on the fly'.
+ */
+ if (watchdog_enabled && watchdog_thresh)
+ err = watchdog_enable_all_cpus(true);
+ else
+ watchdog_disable_all_cpus();
+
+ return err;
+
+}
+
+/*
* proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh
*/