Gabriele Monaco [off-list ref] writes:

+static inline void ha_start_timer_ns(struct ha_monitor *ha_mon, enum envs env,
+				     u64 expire, u64 time_ns)
+{
+	u64 passed = ha_invariant_passed_ns(ha_mon, env, expire, time_ns);
+
+	ha_start_timer_jiffy(ha_mon, ENV_MAX_STORED,
+			     nsecs_to_jiffies(expire - passed) + 1, time_ns);

What is the +1 for? I guess to prevent it being rounded down to zero? If
so, maybe we should do

     nsecs_to_jiffies(expire - passed + TICK_NSEC - 1)

instead.

Anyway, no big deal:
Reviewed-by: Nam Cao <redacted>