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From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>,
	Peng Liu <liupeng17@lenovo.com>,
	Joel Fernandes <joel@joelfernandes.org>
Subject: [PATCH 10/15] tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode
Date: Wed, 24 Jan 2024 18:04:54 +0100	[thread overview]
Message-ID: <20240124170459.24850-11-frederic@kernel.org> (raw)
In-Reply-To: <20240124170459.24850-1-frederic@kernel.org>

The full-nohz update function checks if the nohz mode is active before
proceeding. It considers one exception though: if the tick is already
stopped even though the nohz mode is inactive, it still moves on in
order to update/restart the tick if needed.

However in order for the tick to be stopped, the nohz_mode has to be
either NOHZ_MODE_LOWRES or NOHZ_MODE_HIGHRES. Therefore it doesn't make
sense to test if the tick is stopped before verifying NOHZ_MODE_INACTIVE
mode.

Remove the needless related condition.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
 kernel/time/tick-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e8e3b5d447e9..3104fff89007 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1044,7 +1044,7 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts)
 	if (!tick_nohz_full_cpu(smp_processor_id()))
 		return;
 
-	if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
+	if (ts->nohz_mode == NOHZ_MODE_INACTIVE)
 		return;
 
 	__tick_nohz_full_update_tick(ts, ktime_get());
-- 
2.43.0


  parent reply	other threads:[~2024-01-24 17:05 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-24 17:04 [PATCH 00/15] timers/nohz cleanups and hotplug reorganization Frederic Weisbecker
2024-01-24 17:04 ` [PATCH 01/15] tick/nohz: Remove duplicate between tick_nohz_switch_to_nohz() and tick_setup_sched_timer() Frederic Weisbecker
2024-01-25  9:12   ` Thomas Gleixner
2024-01-25 11:57     ` Frederic Weisbecker
2024-01-25 13:34       ` Thomas Gleixner
2024-01-25 14:35         ` Frederic Weisbecker
2024-01-24 17:04 ` [PATCH 02/15] tick/nohz: Remove duplicate between lowres and highres handlers Frederic Weisbecker
2024-01-25  9:32   ` Thomas Gleixner
2024-01-25 11:58     ` Frederic Weisbecker
2024-01-25 13:30       ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 03/15] tick: Remove useless oneshot ifdeffery Frederic Weisbecker
2024-01-25  9:32   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 04/15] tick: Use IS_ENABLED() whenever possible Frederic Weisbecker
2024-01-25  9:33   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 05/15] tick: s/tick_nohz_stop_sched_tick/tick_nohz_full_stop_tick Frederic Weisbecker
2024-01-25  9:33   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 06/15] tick: No need to clear ts->next_tick again Frederic Weisbecker
2024-01-25  9:33   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 07/15] tick: Start centralizing tick related CPU hotplug operations Frederic Weisbecker
2024-01-25  9:36   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 08/15] tick: Move tick cancellation up to CPUHP_AP_TICK_DYING Frederic Weisbecker
2024-01-25  9:37   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 09/15] tick: Move broadcast " Frederic Weisbecker
2024-01-25  9:38   ` Thomas Gleixner
2024-01-24 17:04 ` Frederic Weisbecker [this message]
2024-01-25  9:39   ` [PATCH 10/15] tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode Thomas Gleixner
2024-01-24 17:04 ` [PATCH 11/15] tick: Move got_idle_tick away from common flags Frederic Weisbecker
2024-01-25  9:40   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 12/15] tick: Move individual bit features to debuggable mask accesses Frederic Weisbecker
2024-01-25  9:41   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 13/15] tick: Split nohz and highres features from nohz_mode Frederic Weisbecker
2024-01-25  9:42   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 14/15] tick: Shut down low-res tick from dying CPU Frederic Weisbecker
2024-01-25  9:43   ` Thomas Gleixner
2024-01-24 17:04 ` [PATCH 15/15] tick: Assume timekeeping is correctly handed over upon last offline idle call Frederic Weisbecker
2024-01-25  9:43   ` Thomas Gleixner
  -- strict thread matches above, loose matches on Subject: below --
2024-01-31 23:11 [PATCH 00/15 v2] timers/nohz cleanups and hotplug reorganization Frederic Weisbecker
2024-01-31 23:11 ` [PATCH 10/15] tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode Frederic Weisbecker

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