2020-04-21 20:13:52 +00:00
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From b7ae4952818be75c5a6069dd33747475b78ecf6c Mon Sep 17 00:00:00 2001
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2020-02-21 18:07:43 +00:00
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Wed, 14 Aug 2019 17:08:58 +0200
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2020-04-21 20:13:52 +00:00
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Subject: [PATCH 293/325] x86: preempt: Check preemption level before looking
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2020-02-21 18:07:43 +00:00
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at lazy-preempt
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2020-04-21 20:13:52 +00:00
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.115-rt48.tar.xz
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2020-02-21 18:07:43 +00:00
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[ Upstream commit 19fc8557f2323c52b26561651ed4d51fc688a740 ]
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Before evaluating the lazy-preempt state it must be ensure that the
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preempt-count is zero.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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---
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arch/x86/include/asm/preempt.h | 2 ++
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1 file changed, 2 insertions(+)
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diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
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index f66708779274..afa0e42ccdd1 100644
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--- a/arch/x86/include/asm/preempt.h
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+++ b/arch/x86/include/asm/preempt.h
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@@ -96,6 +96,8 @@ static __always_inline bool __preempt_count_dec_and_test(void)
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if (____preempt_count_dec_and_test())
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return true;
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#ifdef CONFIG_PREEMPT_LAZY
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+ if (preempt_count())
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+ return false;
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if (current_thread_info()->preempt_lazy_count)
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return false;
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return test_thread_flag(TIF_NEED_RESCHED_LAZY);
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--
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2020-04-09 19:44:24 +00:00
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2.25.1
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2020-02-21 18:07:43 +00:00
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