alarmtimers: Remove the throttle mechanism from alarm_forward_now()

Now that ignored posix timer signals are requeued and the timers are
rearmed on signal delivery the workaround to keep such timers alive and
self rearm them is not longer required.

Remove the unused alarm timer parts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064214.252443020@linutronix.de

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 8543d7f1cdb4590e070b3865abdbe05b9b784999..593e7d561fa867327e48c0fcc4da4b6839458c3d 100644 (file)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -467,35 +467,11 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
 }
 EXPORT_SYMBOL_GPL(alarm_forward);
 
-static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
+u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
 {
        struct alarm_base *base = &alarm_bases[alarm->type];
-       ktime_t now = base->get_ktime();
-
-       if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && throttle) {
-               /*
-                * Same issue as with posix_timer_fn(). Timers which are
-                * periodic but the signal is ignored can starve the system
-                * with a very small interval. The real fix which was
-                * promised in the context of posix_timer_fn() never
-                * materialized, but someone should really work on it.
-                *
-                * To prevent DOS fake @now to be 1 jiffy out which keeps
-                * the overrun accounting correct but creates an
-                * inconsistency vs. timer_gettime(2).
-                */
-               ktime_t kj = NSEC_PER_SEC / HZ;
-
-               if (interval < kj)
-                       now = ktime_add(now, kj);
-       }
-
-       return alarm_forward(alarm, now, interval);
-}
 
-u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
-{
-       return __alarm_forward_now(alarm, interval, false);
+       return alarm_forward(alarm, base->get_ktime(), interval);
 }
 EXPORT_SYMBOL_GPL(alarm_forward_now);