linux-kernel - [PATCH 1/5] cpuidle: Remove unnecessary current_clr_polling_and

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Message-ID: <20241206130408.18690-2-frederic@kernel.org>
Date: Fri,  6 Dec 2024 14:04:04 +0100
From: Frederic Weisbecker <frederic@...nel.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Frederic Weisbecker <frederic@...nel.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	linux-pm@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Marcelo Tosatti <mtosatti@...hat.com>
Subject: [PATCH 1/5] cpuidle: Remove unnecessary current_clr_polling_and_test() from haltpoll

When cpuidle drivers ->enter() callback are called, the TIF_NR_POLLING
flag is cleared already and TIF_NEED_RESCHED checked by call_cpuidle().

Therefore calling current_clr_polling_and_test() is redundant here and
further setting of TIF_NEED_RESCHED will result in an IPI and thus an
idle loop exit. This call can be safely removed.

Cc: Marcelo Tosatti <mtosatti@...hat.com>
Acked-by: Rafael J. Wysocki <rafael@...nel.org>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
---
 drivers/cpuidle/cpuidle-haltpoll.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
index bcd03e893a0a..07dd9f000273 100644
--- a/drivers/cpuidle/cpuidle-haltpoll.c
+++ b/drivers/cpuidle/cpuidle-haltpoll.c
@@ -28,9 +28,6 @@ static enum cpuhp_state haltpoll_hp_state;
 static __cpuidle int default_enter_idle(struct cpuidle_device *dev,
 					struct cpuidle_driver *drv, int index)
 {
-	if (current_clr_polling_and_test())
-		return index;
-
 	arch_cpu_idle();
 	return index;
 }
-- 
2.46.0