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| author | Frederic Weisbecker <frederic@kernel.org> | 2020-07-17 16:05:50 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-17 21:55:25 +0200 |
| commit | 0975fb565b8b8f9e0c96d0de39fcb954833ea5e0 (patch) | |
| tree | ff02bace4e91bfa64b2a1caca7d1b16e1e5af981 /kernel | |
| parent | d4f7dae87096dfe722bf32aa82076ece1063746c (diff) | |
| download | linux-stable-0975fb565b8b8f9e0c96d0de39fcb954833ea5e0.tar.gz linux-stable-0975fb565b8b8f9e0c96d0de39fcb954833ea5e0.tar.bz2 linux-stable-0975fb565b8b8f9e0c96d0de39fcb954833ea5e0.zip | |
timers: Remove must_forward_clk
There is no reason to keep this guard around. The code makes sure that
base->clk remains sane and won't be forwarded beyond jiffies nor set
backward.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200717140551.29076-12-frederic@kernel.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/timer.c | 22 |
1 files changed, 6 insertions, 16 deletions
diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 4f78a7bff9e1..8b3fb52d8c47 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -205,7 +205,6 @@ struct timer_base { unsigned long next_expiry; unsigned int cpu; bool is_idle; - bool must_forward_clk; DECLARE_BITMAP(pending_map, WHEEL_SIZE); struct hlist_head vectors[WHEEL_SIZE]; } ____cacheline_aligned; @@ -888,12 +887,13 @@ get_target_base(struct timer_base *base, unsigned tflags) static inline void forward_timer_base(struct timer_base *base) { - unsigned long jnow; + unsigned long jnow = READ_ONCE(jiffies); - if (!base->must_forward_clk) - return; - - jnow = READ_ONCE(jiffies); + /* + * No need to forward if we are close enough below jiffies. + * Also while executing timers, base->clk is 1 offset ahead + * of jiffies to avoid endless requeuing to current jffies. + */ if ((long)(jnow - base->clk) < 2) return; @@ -1722,16 +1722,8 @@ static inline void __run_timers(struct timer_base *base) timer_base_lock_expiry(base); raw_spin_lock_irq(&base->lock); - /* - * timer_base::must_forward_clk must be cleared before running - * timers so that any timer functions that call mod_timer() will - * not try to forward the base. - */ - base->must_forward_clk = false; - while (time_after_eq(jiffies, base->clk) && time_after_eq(jiffies, base->next_expiry)) { - levels = collect_expired_timers(base, heads); base->clk++; base->next_expiry = __next_timer_interrupt(base); @@ -1739,7 +1731,6 @@ static inline void __run_timers(struct timer_base *base) while (levels--) expire_timers(base, heads + levels); } - base->must_forward_clk = true; raw_spin_unlock_irq(&base->lock); timer_base_unlock_expiry(base); } @@ -1935,7 +1926,6 @@ int timers_prepare_cpu(unsigned int cpu) base->clk = jiffies; base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA; base->is_idle = false; - base->must_forward_clk = true; } return 0; } |