From a0c9cbb93da9b9a0e00907a4a5d2e5f1fed86350 Mon Sep 17 00:00:00 2001 From: Ulrich Obergfell Date: Tue, 14 Apr 2015 15:43:58 -0700 Subject: [PATCH] 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 Signed-off-by: Don Zickus Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/watchdog.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 9a1c78769a33..dcc4990097a2 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -678,6 +678,29 @@ 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 */ -- 2.20.1