diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 018d68e3184e..e09a6b73a1aa 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -321,8 +321,17 @@ config X86_XADD depends on X86_32 && !M386 config X86_PPRO_FENCE - def_bool y + bool "PentiumPro memory ordering errata workaround" depends on M686 || M586MMX || M586TSC || M586 || M486 || M386 || MGEODEGX1 + help + Old PentiumPro multiprocessor systems had errata that could cause memory + operations to violate the x86 ordering standard in rare cases. Enabling this + option will attempt to work around some (but not all) occurances of + this problem, at the cost of much heavier spinlock and memory barrier + operations. + + If unsure, say n here. Even distro kernels should think twice before enabling + this: there are few systems, and an unlikely bug. config X86_F00F_BUG def_bool y