From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 9 Aug 2019 15:25:21 +0200
Subject: [PATCH] hrtimer: Allow raw wakeups during boot
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: da77ceac3d20f27310a07a7c346a4ee6b40d6c28
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
There are a few wake-up timers during the early boot which are essencial for
the system to make progress. At this stage there are no softirq spawn for the
softirq processing so there is no timer processing in softirq.
The wakeup in question:
smpboot_create_thread()
-> kthread_create_on_cpu()
-> kthread_bind()
-> wait_task_inactive()
-> schedule_hrtimeout()
Let the timer fire in hardirq context during the system boot.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
kernel/time/hrtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1816,7 +1816,7 @@ static void __hrtimer_init_sleeper(struc
* expiry.
*/
if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
- if (task_is_realtime(current) && !(mode & HRTIMER_MODE_SOFT))
+ if ((task_is_realtime(current) && !(mode & HRTIMER_MODE_SOFT)) || system_state != SYSTEM_RUNNING)
mode |= HRTIMER_MODE_HARD;
}