timers: Check if timers base is handled already

Due to the conversion of the NOHZ timer placement to a pull at expiry
time model, the per CPU timer bases with non pinned timers are no
longer handled only by the local CPU. In case a remote CPU already
expires the non pinned timers base of the local CPU, nothing more
needs to be done by the local CPU. A check at the begin of the expire
timers routine is required, because timer base lock is dropped before
executing the timer callback function.

This is a preparatory work, but has no functional impact right now.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240221090548.36600-16-anna-maria@linutronix.de

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 51053af..4420cdf 100644 (file)
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -2285,6 +2285,9 @@ static inline void __run_timers(struct timer_base *base)
 
        lockdep_assert_held(&base->lock);
 
+       if (base->running_timer)
+               return;
+
        while (time_after_eq(jiffies, base->clk) &&
               time_after_eq(jiffies, base->next_expiry)) {
                levels = collect_expired_timers(base, heads);