From 1ece596541b3a857f449f35acb8f31bb59e9f84a Mon Sep 17 00:00:00 2001
Message-Id: <1ece596541b3a857f449f35acb8f31bb59e9f84a.1592846147.git.zanussi@kernel.org>
In-Reply-To: <07cd0dbc80b976663c80755496a03f288decfe5a.1592846146.git.zanussi@kernel.org>
References: <07cd0dbc80b976663c80755496a03f288decfe5a.1592846146.git.zanussi@kernel.org>
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 8 Jul 2015 17:14:48 +0200
Subject: [PATCH 038/330] jump-label: disable if stop_machine() is used
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.127-rt55.tar.xz

Some architectures are using stop_machine() while switching the opcode which
leads to latency spikes.
The architectures which use stop_machine() atm:
- ARM stop machine
- s390 stop machine

The architecures which use other sorcery:
- MIPS
- X86
- powerpc
- sparc
- arm64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: only ARM for now]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/arm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e2f7c50dbace..91ba9fe945ff 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -51,7 +51,7 @@ config ARM
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
-	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
+	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU && !PREEMPT_RT_BASE
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
 	select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
-- 
2.17.1

