[patch V2 10/10] timer: Always queue timers on the local CPU

Thomas Gleixner
2017-04-18T16:46:22Z

[-- Attachment #1: timer_Place_timers_on_the_local_CPU.patch --]
[-- Type: text/plain, Size: 1689 bytes --]

The timer pull model is in place so we can remove the heuristics which try
to guess the best target CPU at enqueue/modification time.

All non pinned timers are queued on the local cpu in the seperate storage
and eventually pulled at expiry time to a remote cpu.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
kernel/time/timer.c | 20 +-------------------
1 file changed, 1 insertion(+), 19 deletions(-)

--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -857,18 +857,6 @@ static inline struct timer_base *get_tim
}

#ifdef CONFIG_NO_HZ_COMMON
-static inline struct timer_base *
-get_target_base(struct timer_base *base, unsigned tflags)
-{
-#ifdef CONFIG_SMP
- if ((tflags & TIMER_PINNED) || !base->migration_enabled)
- return get_timer_this_cpu_base(tflags);
- return get_timer_cpu_base(tflags, get_nohz_timer_target());
-#else
- return get_timer_this_cpu_base(tflags);
-#endif
-}
-
static inline void forward_timer_base(struct timer_base *base)
{
unsigned long jnow = READ_ONCE(jiffies);
@@ -890,12 +878,6 @@ static inline void forward_timer_base(st
base->clk = base->next_expiry;
}
#else
-static inline struct timer_base *
-get_target_base(struct timer_base *base, unsigned tflags)
-{
- return get_timer_this_cpu_base(tflags);
-}
-
static inline void forward_timer_base(struct timer_base *base) { }
#endif

@@ -985,7 +967,7 @@ static inline int
if (!ret && pending_only)
goto out_unlock;

- new_base = get_target_base(base, timer->flags);
+ new_base = get_timer_this_cpu_base(timer->flags);

if (base != new_base) {
/*