[PATCH RT 04/23] x86: preempt: Check preemption level before looking at lazy-preempt
From: zanussi@kernel.org
Date: 2020-02-27 14:35:37
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lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> v4.14.170-rt75-rc2 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit 19fc8557f2323c52b26561651ed4d51fc688a740 ] Before evaluating the lazy-preempt state it must be ensure that the preempt-count is zero. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Tom Zanussi <zanussi@kernel.org> --- arch/x86/include/asm/preempt.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index f66708779274..afa0e42ccdd1 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h@@ -96,6 +96,8 @@ static __always_inline bool __preempt_count_dec_and_test(void) if (____preempt_count_dec_and_test()) return true; #ifdef CONFIG_PREEMPT_LAZY + if (preempt_count()) + return false; if (current_thread_info()->preempt_lazy_count) return false; return test_thread_flag(TIF_NEED_RESCHED_LAZY);
--
2.14.1