watchdog: use park/unpark functions in update_watchdog_all_cpus()

Remove update_watchdog() and restart_watchdog_hrtimer() since these
functions are no longer needed.  Changes of parameters such as the sample
period are honored at the time when the watchdog threads are being
unparked.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e6eb5b69721280dcbb6ef454a878caacc5a01f54..eb8f94b501014cf0a4a8edfa59ba42d53ff43e9d 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -745,46 +745,10 @@ void watchdog_resume(void)
        mutex_unlock(&watchdog_proc_mutex);
 }
 
-static void restart_watchdog_hrtimer(void *info)
-{
-       struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer);
-       int ret;
-
-       /*
-        * No need to cancel and restart hrtimer if it is currently executing
-        * because it will reprogram itself with the new period now.
-        * We should never see it unqueued here because we are running per-cpu
-        * with interrupts disabled.
-        */
-       ret = hrtimer_try_to_cancel(hrtimer);
-       if (ret == 1)
-               hrtimer_start(hrtimer, ns_to_ktime(sample_period),
-                               HRTIMER_MODE_REL_PINNED);
-}
-
-static void update_watchdog(int cpu)
-{
-       /*
-        * Make sure that perf event counter will adopt to a new
-        * sampling period. Updating the sampling period directly would
-        * be much nicer but we do not have an API for that now so
-        * let's use a big hammer.
-        * Hrtimer will adopt the new period on the next tick but this
-        * might be late already so we have to restart the timer as well.
-        */
-       watchdog_nmi_disable(cpu);
-       smp_call_function_single(cpu, restart_watchdog_hrtimer, NULL, 1);
-       watchdog_nmi_enable(cpu);
-}
-
 static void update_watchdog_all_cpus(void)
 {
-       int cpu;
-
-       get_online_cpus();
-       for_each_watchdog_cpu(cpu)
-               update_watchdog(cpu);
-       put_online_cpus();
+       watchdog_park_threads();
+       watchdog_unpark_threads();
 }
 
 static int watchdog_enable_all_cpus(void)