From: Thomas Gleixner Date: Wed, 8 Jul 2015 17:14:48 +0200 Subject: [PATCH 038/353] jump-label: disable if stop_machine() is used Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=7475498ce7b14345b197402b874347c3a8a55075 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 [bigeasy: only ARM for now] Signed-off-by: Sebastian Andrzej Siewior --- arch/arm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 41bde0e62e90..48f7fcbe2f37 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)