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From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	linux-pm@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Marcelo Tosatti <mtosatti@redhat.com>
Subject: [PATCH 1/5] cpuidle: Remove unnecessary current_clr_polling_and_test() from haltpoll
Date: Fri,  6 Dec 2024 14:04:04 +0100	[thread overview]
Message-ID: <20241206130408.18690-2-frederic@kernel.org> (raw)
In-Reply-To: <20241206130408.18690-1-frederic@kernel.org>

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@redhat.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.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


  reply	other threads:[~2024-12-06 13:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-06 13:04 [PATCH 0/5] cpuidle: Handle TIF_NR_POLLING on behalf of polling idle states v2 Frederic Weisbecker
2024-12-06 13:04 ` Frederic Weisbecker [this message]
2024-12-06 13:04 ` [PATCH 2/5] cpuidle: Introduce CPUIDLE_FLAG_MWAIT Frederic Weisbecker
2024-12-10 14:03   ` Peter Zijlstra
2024-12-06 13:04 ` [PATCH 3/5] cpuidle: Handle TIF_NR_POLLING on behalf of CPUIDLE_FLAG_MWAIT states Frederic Weisbecker
2024-12-10 14:03   ` Peter Zijlstra
2024-12-18 13:24   ` Rafael J. Wysocki
2024-12-18 14:04     ` Frederic Weisbecker
2024-12-06 13:04 ` [PATCH 4/5] cpuidle: Remove call_cpuidle_s2idle() Frederic Weisbecker
2024-12-06 13:04 ` [PATCH 5/5] cpuidle: Handle TIF_NR_POLLING on behalf of software polling idle states Frederic Weisbecker

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