From aca8026dd8bf090519a71fbe14bceeb21d6749e6 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 8 Jul 2015 17:14:48 +0200
Subject: [PATCH] jump-label: disable if stop_machine() is used
References: SLE Realtime Extension
Patch-mainline: Queued in subsystem maintainer repository
Git-commit: 258b5e7d72c1fe3f55099507ea86a60165973690
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
arch/arm64/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 264863e93811..2e4751f1b391 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -146,7 +146,7 @@ config ARM64
select HAVE_ARCH_BITREVERSE
select HAVE_ARCH_COMPILER_H
select HAVE_ARCH_HUGE_VMAP
- select HAVE_ARCH_JUMP_LABEL
+ select HAVE_ARCH_JUMP_LABEL if !PREEMPT_RT
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN