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 V3 50/51] alarmtimers: Remove the throttle mechanism from alarm_forward_now()
Date: Mon, 10 Jun 2024 18:43:07 +0200 (CEST) [thread overview]
Message-ID: <20240610164028.602391697@linutronix.de> (raw)
In-Reply-To: 20240610163452.591699700@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>
---
kernel/time/alarmtimer.c | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -469,35 +469,11 @@ 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 jiffie 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:[~2024-06-10 16:43 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-10 16:42 [patch V3 00/51] posix-timers: Cure inconsistencies and the SIG_IGN mess Thomas Gleixner
2024-06-10 16:42 ` [patch V3 01/51] selftests/timers/posix_timers: Simplify error handling Thomas Gleixner
2024-06-10 16:42 ` [patch V3 02/51] selftests/timers/posix_timers: Add SIG_IGN test Thomas Gleixner
2024-06-10 16:42 ` [patch V3 03/51] selftests/timers/posix_timers: Validate signal rules Thomas Gleixner
2024-06-10 16:42 ` [patch V3 04/51] selftests/timers/posix-timers: Validate SIGEV_NONE Thomas Gleixner
2024-06-10 16:42 ` [patch V3 05/51] selftests/timers/posix-timers: Validate timer_gettime() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 06/51] selftests/timers/posix-timers: Validate overrun after unblock Thomas Gleixner
2024-06-10 16:42 ` [patch V3 07/51] posix-cpu-timers: Split up posix_cpu_timer_get() Thomas Gleixner
2024-06-21 15:28 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 08/51] posix-cpu-timers: Save interval only for armed timers Thomas Gleixner
2024-06-21 15:33 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 09/51] posix-cpu-timers: Handle interval timers correctly in timer_get() Thomas Gleixner
2024-06-22 9:04 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 10/51] posix-cpu-timers: Handle SIGEV_NONE " Thomas Gleixner
2024-06-22 14:28 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 11/51] posix-cpu-timers: Handle SIGEV_NONE timers correctly in timer_set() Thomas Gleixner
2024-06-22 14:35 ` Frederic Weisbecker
2024-06-22 21:56 ` Thomas Gleixner
2024-06-23 11:16 ` [patch V3-2 " Thomas Gleixner
2024-06-23 19:12 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 12/51] posix-cpu-timers: Replace old expiry retrieval in posix_cpu_timer_set() Thomas Gleixner
2024-06-23 11:17 ` [patch V3-2 " Thomas Gleixner
2024-06-23 20:23 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 13/51] posix-cpu-timers: Do not arm SIGEV_NONE timers Thomas Gleixner
2024-06-23 21:04 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 14/51] posix-cpu-timers: Use @now instead of @val for clarity Thomas Gleixner
2024-06-10 16:42 ` [patch V3 15/51] posix-cpu-timers: Remove incorrect comment in posix_cpu_timer_set() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 16/51] posix-cpu-timers: Simplify posix_cpu_timer_set() Thomas Gleixner
2024-06-23 22:41 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 17/51] posix-timers: Retrieve interval in common timer_settime() code Thomas Gleixner
2024-06-25 15:13 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 18/51] posix-timers: Clear overrun in common_timer_set() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 19/51] posix-timers: Convert timer list to hlist Thomas Gleixner
2024-06-10 16:42 ` [patch V3 20/51] posix-timers: Consolidate timer setup Thomas Gleixner
2024-06-25 22:19 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 21/51] posix-cpu-timers: Make k_itimer::it_active consistent Thomas Gleixner
2024-06-25 22:36 ` Frederic Weisbecker
2024-06-10 16:42 ` [patch V3 22/51] posix-timers: Consolidate signal queueing Thomas Gleixner
2024-06-10 16:42 ` [patch V3 23/51] signal: Remove task argument from dequeue_signal() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 24/51] signal: Replace BUG_ON()s Thomas Gleixner
2024-06-10 16:42 ` [patch V3 25/51] signal: Confine POSIX_TIMERS properly Thomas Gleixner
2024-06-10 16:42 ` [patch V3 26/51] signal: Prevent user space from setting si_sys_private Thomas Gleixner
2024-06-10 16:42 ` [patch V3 27/51] signal: Get rid of resched_timer logic Thomas Gleixner
2024-06-10 16:42 ` [patch V3 28/51] posix-timers: Cure si_sys_private race Thomas Gleixner
2024-06-10 16:42 ` [patch V3 29/51] signal: Allow POSIX timer signals to be dropped Thomas Gleixner
2024-06-10 16:42 ` [patch V3 30/51] posix-timers: Drop signal if timer has been deleted or reprogrammed Thomas Gleixner
2024-06-10 16:42 ` [patch V3 31/51] posix-timers: Rename k_itimer::it_requeue_pending Thomas Gleixner
2024-06-10 16:42 ` [patch V3 32/51] posix-timers: Add proper state tracking Thomas Gleixner
2024-06-10 16:42 ` [patch V3 33/51] posix-timers: Make signal delivery consistent Thomas Gleixner
2024-06-10 16:42 ` [patch V3 34/51] posix-timers: Make signal overrun accounting sensible Thomas Gleixner
2024-06-10 16:42 ` [patch V3 35/51] posix-cpu-timers: Use dedicated flag for CPU timer nanosleep Thomas Gleixner
2024-06-10 16:42 ` [patch V3 36/51] posix-timers: Add a refcount to struct k_itimer Thomas Gleixner
2024-06-10 16:42 ` [patch V3 37/51] signal: Split up __sigqueue_alloc() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 38/51] signal: Provide posixtimer_sigqueue_init() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 39/51] signal: Add sys_private_ptr to siginfo::_sifields::_timer Thomas Gleixner
2024-06-23 11:17 ` Thomas Gleixner
2024-06-10 16:42 ` [patch V3 40/51] posix-timers: Store PID type in the timer Thomas Gleixner
2024-06-10 16:42 ` [patch V3 41/51] signal: Refactor send_sigqueue() Thomas Gleixner
2024-06-10 16:42 ` [patch V3 42/51] posix-timers: Embed sigqueue in struct k_itimer Thomas Gleixner
2024-06-10 16:42 ` [patch V3 43/51] signal: Cleanup unused posix-timer leftovers Thomas Gleixner
2024-06-10 16:42 ` [patch V3 44/51] signal: Add task argument to flush_sigqueue_mask() Thomas Gleixner
2024-06-10 16:43 ` [patch V3 45/51] signal: Provide ignored_posix_timers list Thomas Gleixner
2024-06-10 16:43 ` [patch V3 46/51] posix-timers: Handle ignored list on delete and exit Thomas Gleixner
2024-06-10 16:43 ` [patch V3 47/51] signal: Handle ignored signals in do_sigaction(action != SIG_IGN) Thomas Gleixner
2024-06-10 16:43 ` [patch V3 48/51] signal: Queue ignored posixtimers on ignore list Thomas Gleixner
2024-06-10 16:43 ` [patch V3 49/51] posix-timers: Cleanup SIG_IGN workaround leftovers Thomas Gleixner
2024-06-10 16:43 ` Thomas Gleixner [this message]
2024-06-10 16:43 ` [patch V3 51/51] alarmtimers: Remove return value from alarm functions Thomas Gleixner
2024-06-10 19:49 ` [patch V3 00/51] posix-timers: Cure inconsistencies and the SIG_IGN mess Peter Zijlstra
2024-06-11 6:58 ` Thomas Gleixner
2024-06-23 11:24 ` Thomas Gleixner
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