From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> [ Upstream commit 7a35bf2a6a871cd0252cd371d741e7d070b53af9 ] Now that it's clear that there is always one tick to account, simplify the calculations some more. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20201117132006.565663056@xxxxxxxxxxxxx Stable-dep-of: e9523a0d8189 ("tick/common: Align tick period with the HZ tick.") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/time/tick-sched.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index eaeeb4bb1f8ab..3b00167656d78 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -53,7 +53,7 @@ static ktime_t last_jiffies_update; */ static void tick_do_update_jiffies64(ktime_t now) { - unsigned long ticks = 0; + unsigned long ticks = 1; ktime_t delta; /* @@ -91,20 +91,21 @@ static void tick_do_update_jiffies64(ktime_t now) write_seqcount_begin(&jiffies_seq); - 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); - ticks = ktime_divns(delta, incr); + ticks += ktime_divns(delta, incr); last_jiffies_update = ktime_add_ns(last_jiffies_update, incr * ticks); + } else { + last_jiffies_update = ktime_add(last_jiffies_update, + tick_period); } - do_timer(++ticks); + do_timer(ticks); /* * Keep the tick_next_period variable up to date. WRITE_ONCE() -- 2.39.2
