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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-11-17 14:19:47 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-11-19 10:48:29 +0100 |
| commit | 7a35bf2a6a871cd0252cd371d741e7d070b53af9 (patch) | |
| tree | ca12023fb7277cff6826cdd3f29bfbaa87c4ab1c /kernel/time | |
| parent | 94ad2e3cedb82af034f6d97c58022f162b669f9b (diff) | |
| download | linux-7a35bf2a6a871cd0252cd371d741e7d070b53af9.tar.gz | |
tick/sched: Optimize tick_do_update_jiffies64() further
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> Link: https://lore.kernel.org/r/20201117132006.565663056@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/tick-sched.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index ca9191ced4b5..306adeb6ce4c 100644 --- 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(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() |