33 lines
1.1 KiB
Diff
33 lines
1.1 KiB
Diff
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Tue, 24 May 2016 12:56:38 +0200
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Subject: [PATCH] arm: lazy preempt: correct resched condition
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.6/older/patches-4.6.2-rt5.tar.xz
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If we get out of preempt_schedule_irq() then we check for NEED_RESCHED
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and call the former function again if set because the preemption counter
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has be zero at this point.
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However the counter for lazy-preempt might not be zero therefore we have
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to check the counter before looking at the need_resched_lazy flag.
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Cc: stable-rt@vger.kernel.org
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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arch/arm/kernel/entry-armv.S | 6 +++++-
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1 file changed, 5 insertions(+), 1 deletion(-)
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--- a/arch/arm/kernel/entry-armv.S
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+++ b/arch/arm/kernel/entry-armv.S
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@@ -244,7 +244,11 @@ ENDPROC(__irq_svc)
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bne 1b
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tst r0, #_TIF_NEED_RESCHED_LAZY
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reteq r8 @ go again
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- b 1b
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+ ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
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+ teq r0, #0 @ if preempt lazy count != 0
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+ beq 1b
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+ ret r8 @ go again
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+
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#endif
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__und_fault:
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