From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>,
Frederic Weisbecker <frederic@kernel.org>,
John Stultz <jstultz@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Stephen Boyd <sboyd@kernel.org>,
Eric Biederman <ebiederm@xmission.com>,
Oleg Nesterov <oleg@redhat.com>
Subject: [patch v6 19/20] alarmtimers: Remove the throttle mechanism from alarm_forward_now()
Date: Thu, 31 Oct 2024 16:46:46 +0100 (CET) [thread overview]
Message-ID: <20241031154425.752089279@linutronix.de> (raw)
In-Reply-To: <20241031151625.361697424@linutronix.de>
From: Thomas Gleixner <tglx@linutronix.de>
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>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/time/alarmtimer.c | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)
---
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -467,35 +467,11 @@ u64 alarm_forward(struct alarm *alarm, k
}
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);
next prev parent reply other threads:[~2024-10-31 15:46 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-31 15:46 [patch v6 00/20] posix-timers: Cure the SIG_IGN mess Thomas Gleixner
2024-10-31 15:46 ` [patch v6 01/20] posix-timers: Make signal delivery consistent Thomas Gleixner
2024-11-01 12:26 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 02/20] posix-timers: Make signal overrun accounting sensible Thomas Gleixner
2024-11-01 12:51 ` Frederic Weisbecker
2024-11-01 20:36 ` Thomas Gleixner
2024-11-02 19:41 ` Thomas Gleixner
2024-11-02 22:57 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 03/20] posix-cpu-timers: Cleanup the firing logic Thomas Gleixner
2024-11-01 13:14 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 04/20] posix-cpu-timers: Use dedicated flag for CPU timer nanosleep Thomas Gleixner
2024-10-31 15:46 ` [patch v6 05/20] posix-timers: Add a refcount to struct k_itimer Thomas Gleixner
2024-10-31 15:46 ` [patch v6 06/20] signal: Split up __sigqueue_alloc() Thomas Gleixner
2024-10-31 15:46 ` [patch v6 07/20] signal: Provide posixtimer_sigqueue_init() Thomas Gleixner
2024-10-31 15:46 ` [patch v6 08/20] posix-timers: Store PID type in the timer Thomas Gleixner
2024-10-31 15:46 ` [patch v6 09/20] signal: Refactor send_sigqueue() Thomas Gleixner
2024-10-31 15:46 ` [patch v6 10/20] signal: Replace resched_timer logic Thomas Gleixner
2024-11-01 13:25 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 11/20] posix-timers: Embed sigqueue in struct k_itimer Thomas Gleixner
2024-10-31 15:46 ` [patch v6 12/20] signal: Cleanup unused posix-timer leftovers Thomas Gleixner
2024-10-31 15:46 ` [patch v6 13/20] posix-timers: Move sequence logic into struct k_itimer Thomas Gleixner
2024-10-31 15:46 ` [patch v6 14/20] signal: Provide ignored_posix_timers list Thomas Gleixner
2024-10-31 15:46 ` [patch v6 15/20] posix-timers: Handle ignored list on delete and exit Thomas Gleixner
2024-11-01 13:47 ` Frederic Weisbecker
2024-11-01 20:38 ` Thomas Gleixner
2024-10-31 15:46 ` [patch v6 16/20] signal: Handle ignored signals in do_sigaction(action != SIG_IGN) Thomas Gleixner
2024-11-01 14:04 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 17/20] signal: Queue ignored posixtimers on ignore list Thomas Gleixner
2024-11-01 14:21 ` Frederic Weisbecker
2024-11-01 20:47 ` Thomas Gleixner
2024-11-02 14:49 ` Thomas Gleixner
2024-11-02 20:57 ` Thomas Gleixner
2024-11-02 23:46 ` Frederic Weisbecker
2024-11-03 9:44 ` Thomas Gleixner
2024-11-03 19:55 ` Frederic Weisbecker
2024-11-02 21:05 ` [patch v6.1 " Thomas Gleixner
2024-11-04 11:42 ` Frederic Weisbecker
2024-11-04 15:21 ` Thomas Gleixner
2024-11-04 21:31 ` Thomas Gleixner
2024-11-04 23:02 ` Frederic Weisbecker
2024-10-31 15:46 ` [patch v6 18/20] posix-timers: Cleanup SIG_IGN workaround leftovers Thomas Gleixner
2024-10-31 15:46 ` Thomas Gleixner [this message]
2024-10-31 15:46 ` [patch v6 20/20] alarmtimers: Remove return value from alarm functions Thomas Gleixner
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