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alarmtimers: Remove the throttle mechanism from alarm_forward_now()

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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
This commit is contained in:
Thomas Gleixner 2024-11-05 09:14:56 +01:00
parent 7a66f72b09
commit 6b0aa14578
1 changed files with 3 additions and 27 deletions
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30
kernel/time/alarmtimer.c
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@ -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)
{
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);
struct alarm_base *base = &alarm_bases[alarm->type];
return alarm_forward(alarm, base->get_ktime(), interval);
}
EXPORT_SYMBOL_GPL(alarm_forward_now);