Messages in this thread Patch in this message | | | Date | Tue, 17 Nov 2020 14:19:47 +0100 | From | Thomas Gleixner <> | Subject | [patch 5/7] tick/sched: Optimize tick_do_update_jiffies64() further |
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Now that it's clear that there is always one tick to account, simplify the calculations some more.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/time/tick-sched.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
--- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -55,7 +55,7 @@ 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; /* @@ -93,20 +93,21 @@ static void tick_do_update_jiffies64(kti 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()
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