Update to 5.17.3rc1-1

1 files changed, 86 insertions, 0 deletions

diff --git a/0003-tick-Detect-and-fix-jiffies-update-stall.patch b/0003-tick-Detect-and-fix-jiffies-update-stall.patch
new file mode 100644
index 000000000000..be56c710811d
--- /dev/null
+++ b/0003-tick-Detect-and-fix-jiffies-update-stall.patch
@@ -0,0 +1,86 @@
+From e3fb9a238974e20ab8a7b56e9f6a19e2acdc9b87 Mon Sep 17 00:00:00 2001
+From: Frederic Weisbecker <frederic@kernel.org>
+Date: Wed, 2 Feb 2022 01:01:07 +0100
+Subject: [PATCH 3/9] tick: Detect and fix jiffies update stall
+
+On some rare cases, the timekeeper CPU may be delaying its jiffies
+update duty for a while. Known causes include:
+
+* The timekeeper is waiting on stop_machine in a MULTI_STOP_DISABLE_IRQ
+  or MULTI_STOP_RUN state. Disabled interrupts prevent from timekeeping
+  updates while waiting for the target CPU to complete its
+  stop_machine() callback.
+
+* The timekeeper vcpu has VMEXIT'ed for a long while due to some overload
+  on the host.
+
+Detect and fix these situations with emergency timekeeping catchups.
+
+Original-patch-by: Paul E. McKenney <paulmck@kernel.org>
+Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+---
+ kernel/time/tick-sched.c | 17 +++++++++++++++++
+ kernel/time/tick-sched.h |  4 ++++
+ 2 files changed, 21 insertions(+)
+
+diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
+index 17a283ce2b20..c89f50a7e690 100644
+--- a/kernel/time/tick-sched.c
++++ b/kernel/time/tick-sched.c
+@@ -169,6 +169,8 @@ static ktime_t tick_init_jiffy_update(void)
+ 	return period;
+ }
+ 
++#define MAX_STALLED_JIFFIES 5
++
+ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
+ {
+ 	int cpu = smp_processor_id();
+@@ -196,6 +198,21 @@ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
+ 	if (tick_do_timer_cpu == cpu)
+ 		tick_do_update_jiffies64(now);
+ 
++	/*
++	 * If jiffies update stalled for too long (timekeeper in stop_machine()
++	 * or VMEXIT'ed for several msecs), force an update.
++	 */
++	if (ts->last_tick_jiffies != jiffies) {
++		ts->stalled_jiffies = 0;
++		ts->last_tick_jiffies = READ_ONCE(jiffies);
++	} else {
++		if (++ts->stalled_jiffies == MAX_STALLED_JIFFIES) {
++			tick_do_update_jiffies64(now);
++			ts->stalled_jiffies = 0;
++			ts->last_tick_jiffies = READ_ONCE(jiffies);
++		}
++	}
++
+ 	if (ts->inidle)
+ 		ts->got_idle_tick = 1;
+ }
+diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
+index d952ae393423..504649513399 100644
+--- a/kernel/time/tick-sched.h
++++ b/kernel/time/tick-sched.h
+@@ -49,6 +49,8 @@ enum tick_nohz_mode {
+  * @timer_expires_base:	Base time clock monotonic for @timer_expires
+  * @next_timer:		Expiry time of next expiring timer for debugging purpose only
+  * @tick_dep_mask:	Tick dependency mask - is set, if someone needs the tick
++ * @last_tick_jiffies:	Value of jiffies seen on last tick
++ * @stalled_jiffies:	Number of stalled jiffies detected across ticks
+  */
+ struct tick_sched {
+ 	struct hrtimer			sched_timer;
+@@ -77,6 +79,8 @@ struct tick_sched {
+ 	u64				next_timer;
+ 	ktime_t				idle_expires;
+ 	atomic_t			tick_dep_mask;
++	unsigned long			last_tick_jiffies;
++	unsigned int			stalled_jiffies;
+ };
+ 
+ extern struct tick_sched *tick_get_tick_sched(int cpu);
+-- 
+2.35.1
+