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Date: Mon, 30 Dec 2013 10:40:51 -0800 From: Dave Hansen <dave@...1.net> To: linux-kernel@...r.kernel.org Cc: x86@...nel.org, Dave Hansen <dave@...1.net> Subject: [PATCH 04/12] x86 Kconfig: processor options menu From: Dave Hansen <dave.hansen@...ux.intel.com> This tries to consolidate the actual processor options that someone might want to configure. It's a bit arbitrary how you might separate these, but I at least took a stab at it. The real goal here was to hide stuff that folks will rarely look at, and to make them easier to find when folks _do_ need to change them. Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com> --- linux.git-davehans/arch/x86/Kconfig | 208 ++++++++++++++++++------------------ 1 file changed, 106 insertions(+), 102 deletions(-) diff -puN arch/x86/Kconfig~processor-options arch/x86/Kconfig --- linux.git/arch/x86/Kconfig~processor-options 2013-12-30 10:37:44.541203163 -0800 +++ linux.git-davehans/arch/x86/Kconfig 2013-12-30 10:37:44.546203388 -0800 @@ -264,6 +264,8 @@ source "kernel/Kconfig.freezer" menu "Processor type and features" +menu "Processor Options and Features" + config SMP bool "Symmetric multi-processing support" ---help--- @@ -292,6 +294,110 @@ config SMP If you don't know what to do here, say N. +config MAXSMP + bool "Enable Maximum number of SMP Processors and NUMA Nodes" + depends on X86_64 && SMP && DEBUG_KERNEL + select CPUMASK_OFFSTACK + ---help--- + Enable maximum number of CPUS and NUMA Nodes for this architecture. + If unsure, say N. + +config NR_CPUS + int "Maximum number of CPUs" if SMP && !MAXSMP + range 2 8 if SMP && X86_32 && !X86_BIGSMP + range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK + range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 + default "1" if !SMP + default "8192" if MAXSMP + default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) + default "8" if SMP + ---help--- + This allows you to specify the maximum number of CPUs which this + kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum + supported value is 4096, otherwise the maximum value is 512. The + minimum value which makes sense is 2. + + This is purely to save memory - each supported CPU adds + approximately eight kilobytes to the kernel image. + +config HOTPLUG_CPU + bool "Support for hot-pluggable CPUs" + depends on SMP + ---help--- + Say Y here to allow turning CPUs off and on. CPUs can be + controlled through /sys/devices/system/cpu. + ( Note: power management support will enable this option + automatically on SMP systems. ) + Say N if you want to disable CPU hotplug. + +config BOOTPARAM_HOTPLUG_CPU0 + bool "Set default setting of cpu0_hotpluggable" + default n + depends on HOTPLUG_CPU + ---help--- + Set whether default state of cpu0_hotpluggable is on or off. + + Say Y here to enable CPU0 hotplug by default. If this switch + is turned on, there is no need to give cpu0_hotplug kernel + parameter and the CPU0 hotplug feature is enabled by default. + + Please note: there are two known CPU0 dependencies if you want + to enable the CPU0 hotplug feature either by this switch or by + cpu0_hotplug kernel parameter. + + First, resume from hibernate or suspend always starts from CPU0. + So hibernate and suspend are prevented if CPU0 is offline. + + Second dependency is PIC interrupts always go to CPU0. CPU0 can not + offline if any interrupt can not migrate out of CPU0. There may + be other CPU0 dependencies. + + Please make sure the dependencies are under your control before + you enable this feature. + + Say N if you don't want to enable CPU0 hotplug feature by default. + You still can enable the CPU0 hotplug feature at boot by kernel + parameter cpu0_hotplug. + +config DEBUG_HOTPLUG_CPU0 + def_bool n + prompt "Debug CPU0 hotplug" + depends on HOTPLUG_CPU + ---help--- + Enabling this option offlines CPU0 (if CPU0 can be offlined) as + soon as possible and boots up userspace with CPU0 offlined. User + can online CPU0 back after boot time. + + To debug CPU0 hotplug, you need to enable CPU0 offline/online + feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during + compilation or giving cpu0_hotplug kernel parameter at boot. + + If unsure, say N. + +source "arch/x86/Kconfig.cpu" + +config ARCH_RANDOM + def_bool y + prompt "x86 architectural random number generator" if EXPERT + ---help--- + Enable the x86 architectural RDRAND instruction + (Intel Bull Mountain technology) to generate random numbers. + If supported, this is a high bandwidth, cryptographically + secure hardware random number generator. + +config X86_SMAP + def_bool y + prompt "Supervisor Mode Access Prevention" if EXPERT + ---help--- + Supervisor Mode Access Prevention (SMAP) is a security + feature in newer Intel processors. There is a small + performance cost if this enabled and turned on; there is + also a small increase in the kernel size if this is enabled. + + If unsure, say Y. + +endmenu # Processor Options + config X86_X2APIC bool "Support x2apic" depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP @@ -1025,8 +1131,6 @@ config X86_CYCLONE_TIMER def_bool y depends on X86_SUMMIT -source "arch/x86/Kconfig.cpu" - config HPET_TIMER def_bool X86_64 prompt "HPET Timer Support" if X86_32 @@ -1137,32 +1241,6 @@ config IOMMU_HELPER def_bool y depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU -config MAXSMP - bool "Enable Maximum number of SMP Processors and NUMA Nodes" - depends on X86_64 && SMP && DEBUG_KERNEL - select CPUMASK_OFFSTACK - ---help--- - Enable maximum number of CPUS and NUMA Nodes for this architecture. - If unsure, say N. - -config NR_CPUS - int "Maximum number of CPUs" if SMP && !MAXSMP - range 2 8 if SMP && X86_32 && !X86_BIGSMP - range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK - range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 - default "1" if !SMP - default "8192" if MAXSMP - default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) - default "8" if SMP - ---help--- - This allows you to specify the maximum number of CPUs which this - kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum - supported value is 4096, otherwise the maximum value is 512. The - minimum value which makes sense is 2. - - This is purely to save memory - each supported CPU adds - approximately eight kilobytes to the kernel image. - config SCHED_SMT bool "SMT (Hyperthreading) scheduler support" depends on X86_HT @@ -1550,26 +1628,6 @@ config ARCH_USES_PG_UNCACHED def_bool y depends on X86_PAT -config ARCH_RANDOM - def_bool y - prompt "x86 architectural random number generator" if EXPERT - ---help--- - Enable the x86 architectural RDRAND instruction - (Intel Bull Mountain technology) to generate random numbers. - If supported, this is a high bandwidth, cryptographically - secure hardware random number generator. - -config X86_SMAP - def_bool y - prompt "Supervisor Mode Access Prevention" if EXPERT - ---help--- - Supervisor Mode Access Prevention (SMAP) is a security - feature in newer Intel processors. There is a small - performance cost if this enabled and turned on; there is - also a small increase in the kernel size if this is enabled. - - If unsure, say Y. - config EFI bool "EFI runtime service support" depends on ACPI @@ -1755,60 +1813,6 @@ config PHYSICAL_ALIGN Don't change this unless you know what you are doing. -config HOTPLUG_CPU - bool "Support for hot-pluggable CPUs" - depends on SMP - ---help--- - Say Y here to allow turning CPUs off and on. CPUs can be - controlled through /sys/devices/system/cpu. - ( Note: power management support will enable this option - automatically on SMP systems. ) - Say N if you want to disable CPU hotplug. - -config BOOTPARAM_HOTPLUG_CPU0 - bool "Set default setting of cpu0_hotpluggable" - default n - depends on HOTPLUG_CPU - ---help--- - Set whether default state of cpu0_hotpluggable is on or off. - - Say Y here to enable CPU0 hotplug by default. If this switch - is turned on, there is no need to give cpu0_hotplug kernel - parameter and the CPU0 hotplug feature is enabled by default. - - Please note: there are two known CPU0 dependencies if you want - to enable the CPU0 hotplug feature either by this switch or by - cpu0_hotplug kernel parameter. - - First, resume from hibernate or suspend always starts from CPU0. - So hibernate and suspend are prevented if CPU0 is offline. - - Second dependency is PIC interrupts always go to CPU0. CPU0 can not - offline if any interrupt can not migrate out of CPU0. There may - be other CPU0 dependencies. - - Please make sure the dependencies are under your control before - you enable this feature. - - Say N if you don't want to enable CPU0 hotplug feature by default. - You still can enable the CPU0 hotplug feature at boot by kernel - parameter cpu0_hotplug. - -config DEBUG_HOTPLUG_CPU0 - def_bool n - prompt "Debug CPU0 hotplug" - depends on HOTPLUG_CPU - ---help--- - Enabling this option offlines CPU0 (if CPU0 can be offlined) as - soon as possible and boots up userspace with CPU0 offlined. User - can online CPU0 back after boot time. - - To debug CPU0 hotplug, you need to enable CPU0 offline/online - feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during - compilation or giving cpu0_hotplug kernel parameter at boot. - - If unsure, say N. - config COMPAT_VDSO def_bool y prompt "Compat VDSO support" _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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