[tip:timers/core] watchdog: Mark watchdog_hrtimer to expire in hard interrupt context

From: tip-bot for Sebastian Andrzej Siewior
Date: Thu Aug 01 2019 - 11:55:28 EST


Commit-ID: 854bdb3cbde94bb953cd49942762b03e69ac3842
Gitweb: https://git.kernel.org/tip/854bdb3cbde94bb953cd49942762b03e69ac3842
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Fri, 26 Jul 2019 20:30:54 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 1 Aug 2019 17:43:18 +0200

watchdog: Mark watchdog_hrtimer to expire in hard interrupt context

The watchdog hrtimer must expire in hard interrupt context even on
PREEMPT_RT=y kernels as otherwise the hard/softlockup detection logic would
not work.

No functional change.

[ tglx: Split out from larger combo patch. Added changelog ]

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190726185753.262895510@xxxxxxxxxxxxx


---
kernel/watchdog.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 7f9e7b9306fe..f41334ef0971 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -490,10 +490,10 @@ static void watchdog_enable(unsigned int cpu)
* Start the timer first to prevent the NMI watchdog triggering
* before the timer has a chance to fire.
*/
- hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
hrtimer->function = watchdog_timer_fn;
hrtimer_start(hrtimer, ns_to_ktime(sample_period),
- HRTIMER_MODE_REL_PINNED);
+ HRTIMER_MODE_REL_PINNED_HARD);

/* Initialize timestamp */
__touch_watchdog();