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-rw-r--r--kernel/time/tick-common.c4
-rw-r--r--kernel/time/tick-sched.c4
2 files changed, 6 insertions, 2 deletions
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 6c9c342dd0e5..68504eb0d38b 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -27,7 +27,9 @@
*/
DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
/*
- * Tick next event: keeps track of the tick time
+ * Tick next event: keeps track of the tick time. It's updated by the
+ * CPU which handles the tick and protected by jiffies_lock. There is
+ * no requirement to write hold the jiffies seqcount for it.
*/
ktime_t tick_next_period;
ktime_t tick_period;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 81632cd5e3b7..15360e652c85 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -44,7 +44,9 @@ struct tick_sched *tick_get_tick_sched(int cpu)
#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
/*
- * The time, when the last jiffy update happened. Protected by jiffies_lock.
+ * The time, when the last jiffy update happened. Write access must hold
+ * jiffies_lock and jiffies_seq. tick_nohz_next_event() needs to get a
+ * consistent view of jiffies and last_jiffies_update.
*/
static ktime_t last_jiffies_update;