rt-patches/0177-jump-label-disable-if-stop_machine-is-used.patch

   1 From 916417a6f24e60263e9a65b776b263d7c54f5976 Mon Sep 17 00:00:00 2001
   2 From: Thomas Gleixner <tglx@linutronix.de>
   3 Date: Wed, 8 Jul 2015 17:14:48 +0200
   4 Subject: [PATCH 177/366] jump-label: disable if stop_machine() is used
   5
   6 Some architectures are using stop_machine() while switching the opcode which
   7 leads to latency spikes.
   8 The architectures which use stop_machine() atm:
   9 - ARM stop machine
  10 - s390 stop machine
  11
  12 The architecures which use other sorcery:
  13 - MIPS
  14 - X86
  15 - powerpc
  16 - sparc
  17 - arm64
  18
  19 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  20 [bigeasy: only ARM for now]
  21 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  22 ---
  23  arch/arm/Kconfig | 2 +-
  24  1 file changed, 1 insertion(+), 1 deletion(-)
  25
  26 diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
  27 index d3159ff..5e24da7 100644
  28 --- a/arch/arm/Kconfig
  29 +++ b/arch/arm/Kconfig
  30 @@ -33,7 +33,7 @@ config ARM
  31         select HARDIRQS_SW_RESEND
  32         select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
  33         select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
  34 -       select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32
  35 +       select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !PREEMPT_RT_BASE
  36         select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32
  37         select HAVE_ARCH_MMAP_RND_BITS if MMU
  38         select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
  39 --
  40 1.9.1
  41