diff options
| -rw-r--r-- | kernel/time/tick-sched.c | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index b4b6abc81e4a..ca9191ced4b5 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -86,38 +86,35 @@ static void tick_do_update_jiffies64(ktime_t now) /* Reevaluate with jiffies_lock held */ raw_spin_lock(&jiffies_lock); + if (ktime_before(now, tick_next_period)) { + raw_spin_unlock(&jiffies_lock); + return; + } + write_seqcount_begin(&jiffies_seq); - delta = ktime_sub(now, last_jiffies_update); - if (delta >= tick_period) { + last_jiffies_update = ktime_add(last_jiffies_update, tick_period); - delta = ktime_sub(delta, tick_period); - last_jiffies_update = ktime_add(last_jiffies_update, - tick_period); + delta = ktime_sub(now, tick_next_period); + if (unlikely(delta >= tick_period)) { + /* Slow path for long idle sleep times */ + s64 incr = ktime_to_ns(tick_period); - /* Slow path for long timeouts */ - if (unlikely(delta >= tick_period)) { - s64 incr = ktime_to_ns(tick_period); + ticks = ktime_divns(delta, incr); - ticks = ktime_divns(delta, incr); + last_jiffies_update = ktime_add_ns(last_jiffies_update, + incr * ticks); + } - last_jiffies_update = ktime_add_ns(last_jiffies_update, - incr * ticks); - } - do_timer(++ticks); + do_timer(++ticks); + + /* + * Keep the tick_next_period variable up to date. WRITE_ONCE() + * pairs with the READ_ONCE() in the lockless quick check above. + */ + WRITE_ONCE(tick_next_period, + ktime_add(last_jiffies_update, tick_period)); - /* - * Keep the tick_next_period variable up to date. - * WRITE_ONCE() pairs with the READ_ONCE() in the lockless - * quick check above. - */ - WRITE_ONCE(tick_next_period, - ktime_add(last_jiffies_update, tick_period)); - } else { - write_seqcount_end(&jiffies_seq); - raw_spin_unlock(&jiffies_lock); - return; - } write_seqcount_end(&jiffies_seq); raw_spin_unlock(&jiffies_lock); update_wall_time(); |