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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 10/16] tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode
Date: Sun, 25 Feb 2024 23:55:02 +0100	[thread overview]
Message-ID: <20240225225508.11587-11-frederic@kernel.org> (raw)
In-Reply-To: <20240225225508.11587-1-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.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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 b17895de26b9..b79f5403433b 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1086,7 +1086,7 @@ 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:[~2024-02-25 22:55 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-25 22:54 [PATCH 00/16 v3] timers/nohz cleanups and hotplug reorganization Frederic Weisbecker
2024-02-25 22:54 ` [PATCH 01/16] tick/nohz: Remove duplicate between tick_nohz_switch_to_nohz() and tick_setup_sched_timer() Frederic Weisbecker
2024-02-26  8:14   ` Thomas Gleixner
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Peng Liu
2024-02-25 22:54 ` [PATCH 02/16] tick/nohz: Remove duplicate between lowres and highres handlers Frederic Weisbecker
2024-02-26  8:15   ` Thomas Gleixner
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Peng Liu
2024-02-25 22:54 ` [PATCH 03/16] tick: Remove useless oneshot ifdeffery Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] tick/sched: " tip-bot2 for Frederic Weisbecker
2024-02-25 22:54 ` [PATCH 04/16] tick: Use IS_ENABLED() whenever possible Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:54 ` [PATCH 05/16] tick: s/tick_nohz_stop_sched_tick/tick_nohz_full_stop_tick Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] tick/sched: Rename tick_nohz_stop_sched_tick() to tick_nohz_full_stop_tick() tip-bot2 for Frederic Weisbecker
2024-02-25 22:54 ` [PATCH 06/16] tick: No need to clear ts->next_tick again Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] tick/sched: Don't clear ts::next_tick again in can_stop_idle_tick() tip-bot2 for Frederic Weisbecker
2024-02-25 22:54 ` [PATCH 07/16] tick: Start centralizing tick related CPU hotplug operations Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 08/16] tick: Move tick cancellation up to CPUHP_AP_TICK_DYING Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 09/16] tick: Move broadcast " Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` Frederic Weisbecker [this message]
2024-02-26 22:24   ` [tip: timers/core] tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 11/16] tick: Move got_idle_tick away from common flags Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 12/16] tick: Move individual bit features to debuggable mask accesses Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 13/16] tick: Split nohz and highres features from nohz_mode Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 14/16] tick: Shut down low-res tick from dying CPU Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 15/16] tick: Assume timekeeping is correctly handed over upon last offline idle call Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2024-02-25 22:55 ` [PATCH 16/16] timers: Assert no next dyntick timer look-up while CPU is offline Frederic Weisbecker
2024-02-26 22:24   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker

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