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From: Valentin Schneider <valentin.schneider@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Julien Thierry <julien.thierry@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Julien Grall <julien.grall@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 1/3] arm64: entry: Remove unneeded need_resched() loop
Date: Thu, 31 Jan 2019 18:23:37 +0000	[thread overview]
Message-ID: <20190131182339.9835-2-valentin.schneider@arm.com> (raw)
In-Reply-To: <20190131182339.9835-1-valentin.schneider@arm.com>

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.

Reported-by: Julien Thierry <julien.thierry@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/kernel/entry.S | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 0ec0c46b2c0c..4d0c81f29a60 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -611,7 +611,7 @@ el1_irq:
 #ifdef CONFIG_PREEMPT
 	ldr	x24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
 	cbnz	x24, 1f				// preempt count != 0
-	bl	el1_preempt
+	bl	preempt_schedule_irq		// irq en/disable is done inside
 1:
 #endif
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -620,15 +620,6 @@ el1_irq:
 	kernel_exit 1
 ENDPROC(el1_irq)
 
-#ifdef CONFIG_PREEMPT
-el1_preempt:
-	mov	x24, lr
-1:	bl	preempt_schedule_irq		// irq en/disable is done inside
-	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get new tasks TI_FLAGS
-	tbnz	x0, #TIF_NEED_RESCHED, 1b	// needs rescheduling?
-	ret	x24
-#endif
-
 /*
  * EL0 mode handlers.
  */
-- 
2.20.1


  reply	other threads:[~2019-01-31 18:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-31 18:23 [RFC PATCH 0/3] arm/arm64: entry: Remove need_resched() loop Valentin Schneider
2019-01-31 18:23 ` Valentin Schneider [this message]
2019-02-01  8:46   ` [RFC PATCH 1/3] arm64: entry: Remove unneeded " Julien Thierry
2019-02-01 10:21   ` Will Deacon
2019-02-04 16:55   ` Catalin Marinas
2019-01-31 18:23 ` [RFC PATCH 2/3] ARM: " Valentin Schneider
2019-02-01  8:49   ` Julien Thierry
2019-01-31 18:23 ` [RFC PATCH 3/3] sched/Documentation: Point out use of preempt_schedule_irq() Valentin Schneider
2019-02-01  8:45   ` Julien Thierry
2019-02-01 10:27     ` Valentin Schneider

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