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Diffstat (limited to 'arch/x86/Kconfig')
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diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index d47b5a2..34517bf 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -151,7 +151,1059 @@ config X86_TRAMPOLINE config KTIME_SCALAR def_bool X86_32 +source "init/Kconfig" +menu "Processor type and features" + +source "kernel/time/Kconfig" + +config SMP + bool "Symmetric multi-processing support" + ---help--- + This enables support for systems with more than one CPU. If you have + a system with only one CPU, like most personal computers, say N. If + you have a system with more than one CPU, say Y. + + If you say N here, the kernel will run on single and multiprocessor + machines, but will use only one CPU of a multiprocessor machine. If + you say Y here, the kernel will run on many, but not all, + singleprocessor machines. On a singleprocessor machine, the kernel + will run faster if you say N here. + + Note that if you say Y here and choose architecture "586" or + "Pentium" under "Processor family", the kernel will not work on 486 + architectures. Similarly, multiprocessor kernels for the "PPro" + architecture may not work on all Pentium based boards. + + People using multiprocessor machines who say Y here should also say + Y to "Enhanced Real Time Clock Support", below. The "Advanced Power + Management" code will be disabled if you say Y here. + + See also the <file:Documentation/smp.txt>, + <file:Documentation/i386/IO-APIC.txt>, + <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at + <http://www.tldp.org/docs.html#howto>. + + If you don't know what to do here, say N. + +choice + prompt "Subarchitecture Type" + default X86_PC + +config X86_PC + bool "PC-compatible" + help + Choose this option if your computer is a standard PC or compatible. + +config X86_ELAN + bool "AMD Elan" + depends on X86_32 + help + Select this for an AMD Elan processor. + + Do not use this option for K6/Athlon/Opteron processors! + + If unsure, choose "PC-compatible" instead. + +config X86_VOYAGER + bool "Voyager (NCR)" + depends on X86_32 + select SMP if !BROKEN + help + Voyager is an MCA-based 32-way capable SMP architecture proprietary + to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based. + + *** WARNING *** + + If you do not specifically know you have a Voyager based machine, + say N here, otherwise the kernel you build will not be bootable. + +config X86_NUMAQ + bool "NUMAQ (IBM/Sequent)" + select SMP + select NUMA + depends on X86_32 + help + This option is used for getting Linux to run on a (IBM/Sequent) NUMA + multiquad box. This changes the way that processors are bootstrapped, + and uses Clustered Logical APIC addressing mode instead of Flat Logical. + You will need a new lynxer.elf file to flash your firmware with - send + email to <Martin.Bligh@us.ibm.com>. + +config X86_SUMMIT + bool "Summit/EXA (IBM x440)" + depends on X86_32 && SMP + help + This option is needed for IBM systems that use the Summit/EXA chipset. + In particular, it is needed for the x440. + + If you don't have one of these computers, you should say N here. + If you want to build a NUMA kernel, you must select ACPI. + +config X86_BIGSMP + bool "Support for other sub-arch SMP systems with more than 8 CPUs" + depends on X86_32 && SMP + help + This option is needed for the systems that have more than 8 CPUs + and if the system is not of any sub-arch type above. + + If you don't have such a system, you should say N here. + +config X86_VISWS + bool "SGI 320/540 (Visual Workstation)" + depends on X86_32 + help + The SGI Visual Workstation series is an IA32-based workstation + based on SGI systems chips with some legacy PC hardware attached. + + Say Y here to create a kernel to run on the SGI 320 or 540. + + A kernel compiled for the Visual Workstation will not run on PCs + and vice versa. See <file:Documentation/sgi-visws.txt> for details. + +config X86_GENERICARCH + bool "Generic architecture (Summit, bigsmp, ES7000, default)" + depends on X86_32 + help + This option compiles in the Summit, bigsmp, ES7000, default subarchitectures. + It is intended for a generic binary kernel. + If you want a NUMA kernel, select ACPI. We need SRAT for NUMA. + +config X86_ES7000 + bool "Support for Unisys ES7000 IA32 series" + depends on X86_32 && SMP + help + Support for Unisys ES7000 systems. Say 'Y' here if this kernel is + supposed to run on an IA32-based Unisys ES7000 system. + Only choose this option if you have such a system, otherwise you + should say N here. + +config X86_VSMP + bool "Support for ScaleMP vSMP" + depends on X86_64 && PCI + help + Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is + supposed to run on these EM64T-based machines. Only choose this option + if you have one of these machines. + +endchoice + +config SCHED_NO_NO_OMIT_FRAME_POINTER + bool "Single-depth WCHAN output" + default y + depends on X86_32 + help + Calculate simpler /proc/<PID>/wchan values. If this option + is disabled then wchan values will recurse back to the + caller function. This provides more accurate wchan values, + at the expense of slightly more scheduling overhead. + + If in doubt, say "Y". + +config PARAVIRT + bool + depends on X86_32 && !(X86_VISWS || X86_VOYAGER) + help + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. However, when run without a hypervisor + the kernel is theoretically slower and slightly larger. + +menuconfig PARAVIRT_GUEST + bool "Paravirtualized guest support" + depends on X86_32 + help + Say Y here to get to see options related to running Linux under + various hypervisors. This option alone does not add any kernel code. + + If you say N, all options in this submenu will be skipped and disabled. + +if PARAVIRT_GUEST + +source "arch/x86/xen/Kconfig" + +config VMI + bool "VMI Guest support" + select PARAVIRT + depends on !(X86_VISWS || X86_VOYAGER) + help + VMI provides a paravirtualized interface to the VMware ESX server + (it could be used by other hypervisors in theory too, but is not + at the moment), by linking the kernel to a GPL-ed ROM module + provided by the hypervisor. + +source "arch/x86/lguest/Kconfig" + +endif + +config ACPI_SRAT + bool + default y + depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH) + select ACPI_NUMA + +config HAVE_ARCH_PARSE_SRAT + bool + default y + depends on ACPI_SRAT + +config X86_SUMMIT_NUMA + bool + default y + depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH) + +config X86_CYCLONE_TIMER + bool + default y + depends on X86_32 && X86_SUMMIT || X86_GENERICARCH + +config ES7000_CLUSTERED_APIC + bool + default y + depends on SMP && X86_ES7000 && MPENTIUMIII + +source "arch/x86/Kconfig.cpu" + +config HPET_TIMER + bool + prompt "HPET Timer Support" if X86_32 + default X86_64 + help + Use the IA-PC HPET (High Precision Event Timer) to manage + time in preference to the PIT and RTC, if a HPET is + present. + HPET is the next generation timer replacing legacy 8254s. + The HPET provides a stable time base on SMP + systems, unlike the TSC, but it is more expensive to access, + as it is off-chip. You can find the HPET spec at + <http://www.intel.com/hardwaredesign/hpetspec.htm>. + + You can safely choose Y here. However, HPET will only be + activated if the platform and the BIOS support this feature. + Otherwise the 8254 will be used for timing services. + + Choose N to continue using the legacy 8254 timer. + +config HPET_EMULATE_RTC + bool + depends on HPET_TIMER && RTC=y + default y + +# Mark as embedded because too many people got it wrong. +# The code disables itself when not needed. +config GART_IOMMU + bool "GART IOMMU support" if EMBEDDED + default y + select SWIOTLB + select AGP + depends on X86_64 && PCI + help + Support for full DMA access of devices with 32bit memory access only + on systems with more than 3GB. This is usually needed for USB, + sound, many IDE/SATA chipsets and some other devices. + Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART + based hardware IOMMU and a software bounce buffer based IOMMU used + on Intel systems and as fallback. + The code is only active when needed (enough memory and limited + device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified + too. + +config CALGARY_IOMMU + bool "IBM Calgary IOMMU support" + select SWIOTLB + depends on X86_64 && PCI && EXPERIMENTAL + help + Support for hardware IOMMUs in IBM's xSeries x366 and x460 + systems. Needed to run systems with more than 3GB of memory + properly with 32-bit PCI devices that do not support DAC + (Double Address Cycle). Calgary also supports bus level + isolation, where all DMAs pass through the IOMMU. This + prevents them from going anywhere except their intended + destination. This catches hard-to-find kernel bugs and + mis-behaving drivers and devices that do not use the DMA-API + properly to set up their DMA buffers. The IOMMU can be + turned off at boot time with the iommu=off parameter. + Normally the kernel will make the right choice by itself. + If unsure, say Y. + +config CALGARY_IOMMU_ENABLED_BY_DEFAULT + bool "Should Calgary be enabled by default?" + default y + depends on CALGARY_IOMMU + help + Should Calgary be enabled by default? if you choose 'y', Calgary + will be used (if it exists). If you choose 'n', Calgary will not be + used even if it exists. If you choose 'n' and would like to use + Calgary anyway, pass 'iommu=calgary' on the kernel command line. + If unsure, say Y. + +# need this always selected by IOMMU for the VIA workaround +config SWIOTLB + bool + help + Support for software bounce buffers used on x86-64 systems + which don't have a hardware IOMMU (e.g. the current generation + of Intel's x86-64 CPUs). Using this PCI devices which can only + access 32-bits of memory can be used on systems with more than + 3 GB of memory. If unsure, say Y. + + +config NR_CPUS + int "Maximum number of CPUs (2-255)" + range 2 255 + depends on SMP + default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 + default "8" + help + This allows you to specify the maximum number of CPUs which this + kernel will support. The maximum supported value is 255 and 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_64 && SMP) || (X86_32 && X86_HT) + help + SMT scheduler support improves the CPU scheduler's decision making + when dealing with Intel Pentium 4 chips with HyperThreading at a + cost of slightly increased overhead in some places. If unsure say + N here. + +config SCHED_MC + bool "Multi-core scheduler support" + depends on (X86_64 && SMP) || (X86_32 && X86_HT) + default y + help + Multi-core scheduler support improves the CPU scheduler's decision + making when dealing with multi-core CPU chips at a cost of slightly + increased overhead in some places. If unsure say N here. + +source "kernel/Kconfig.preempt" + +config X86_UP_APIC + bool "Local APIC support on uniprocessors" + depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH) + help + A local APIC (Advanced Programmable Interrupt Controller) is an + integrated interrupt controller in the CPU. If you have a single-CPU + system which has a processor with a local APIC, you can say Y here to + enable and use it. If you say Y here even though your machine doesn't + have a local APIC, then the kernel will still run with no slowdown at + all. The local APIC supports CPU-generated self-interrupts (timer, + performance counters), and the NMI watchdog which detects hard + lockups. + +config X86_UP_IOAPIC + bool "IO-APIC support on uniprocessors" + depends on X86_UP_APIC + help + An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an + SMP-capable replacement for PC-style interrupt controllers. Most + SMP systems and many recent uniprocessor systems have one. + + If you have a single-CPU system with an IO-APIC, you can say Y here + to use it. If you say Y here even though your machine doesn't have + an IO-APIC, then the kernel will still run with no slowdown at all. + +config X86_LOCAL_APIC + bool + depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH)) + default y + +config X86_IO_APIC + bool + depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH)) + default y + +config X86_VISWS_APIC + bool + depends on X86_32 && X86_VISWS + default y + +config X86_MCE + bool "Machine Check Exception" + depends on !X86_VOYAGER + ---help--- + Machine Check Exception support allows the processor to notify the + kernel if it detects a problem (e.g. overheating, component failure). + The action the kernel takes depends on the severity of the problem, + ranging from a warning message on the console, to halting the machine. + Your processor must be a Pentium or newer to support this - check the + flags in /proc/cpuinfo for mce. Note that some older Pentium systems + have a design flaw which leads to false MCE events - hence MCE is + disabled on all P5 processors, unless explicitly enabled with "mce" + as a boot argument. Similarly, if MCE is built in and creates a + problem on some new non-standard machine, you can boot with "nomce" + to disable it. MCE support simply ignores non-MCE processors like + the 386 and 486, so nearly everyone can say Y here. + +config X86_MCE_INTEL + bool "Intel MCE features" + depends on X86_64 && X86_MCE && X86_LOCAL_APIC + default y + help + Additional support for intel specific MCE features such as + the thermal monitor. + +config X86_MCE_AMD + bool "AMD MCE features" + depends on X86_64 && X86_MCE && X86_LOCAL_APIC + default y + help + Additional support for AMD specific MCE features such as + the DRAM Error Threshold. + +config X86_MCE_NONFATAL + tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" + depends on X86_32 && X86_MCE + help + Enabling this feature starts a timer that triggers every 5 seconds which + will look at the machine check registers to see if anything happened. + Non-fatal problems automatically get corrected (but still logged). + Disable this if you don't want to see these messages. + Seeing the messages this option prints out may be indicative of dying + or out-of-spec (ie, overclocked) hardware. + This option only does something on certain CPUs. + (AMD Athlon/Duron and Intel Pentium 4) + +config X86_MCE_P4THERMAL + bool "check for P4 thermal throttling interrupt." + depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS + help + Enabling this feature will cause a message to be printed when the P4 + enters thermal throttling. + +config VM86 + bool "Enable VM86 support" if EMBEDDED + default y + depends on X86_32 + help + This option is required by programs like DOSEMU to run 16-bit legacy + code on X86 processors. It also may be needed by software like + XFree86 to initialize some video cards via BIOS. Disabling this + option saves about 6k. + +config TOSHIBA + tristate "Toshiba Laptop support" + depends on X86_32 + ---help--- + This adds a driver to safely access the System Management Mode of + the CPU on Toshiba portables with a genuine Toshiba BIOS. It does + not work on models with a Phoenix BIOS. The System Management Mode + is used to set the BIOS and power saving options on Toshiba portables. + + For information on utilities to make use of this driver see the + Toshiba Linux utilities web site at: + <http://www.buzzard.org.uk/toshiba/>. + + Say Y if you intend to run this kernel on a Toshiba portable. + Say N otherwise. + +config I8K + tristate "Dell laptop support" + depends on X86_32 + ---help--- + This adds a driver to safely access the System Management Mode + of the CPU on the Dell Inspiron 8000. The System Management Mode + is used to read cpu temperature and cooling fan status and to + control the fans on the I8K portables. + + This driver has been tested only on the Inspiron 8000 but it may + also work with other Dell laptops. You can force loading on other + models by passing the parameter `force=1' to the module. Use at + your own risk. + + For information on utilities to make use of this driver see the + I8K Linux utilities web site at: + <http://people.debian.org/~dz/i8k/> + + Say Y if you intend to run this kernel on a Dell Inspiron 8000. + Say N otherwise. + +config X86_REBOOTFIXUPS + bool "Enable X86 board specific fixups for reboot" + depends on X86_32 && X86 + default n + ---help--- + This enables chipset and/or board specific fixups to be done + in order to get reboot to work correctly. This is only needed on + some combinations of hardware and BIOS. The symptom, for which + this config is intended, is when reboot ends with a stalled/hung + system. + + Currently, the only fixup is for the Geode machines using + CS5530A and CS5536 chipsets. + + Say Y if you want to enable the fixup. Currently, it's safe to + enable this option even if you don't need it. + Say N otherwise. + +config MICROCODE + tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support" + select FW_LOADER + ---help--- + If you say Y here, you will be able to update the microcode on + Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II, + Pentium III, Pentium 4, Xeon etc. You will obviously need the + actual microcode binary data itself which is not shipped with the + Linux kernel. + + For latest news and information on obtaining all the required + ingredients for this driver, check: + <http://www.urbanmyth.org/microcode/>. + + To compile this driver as a module, choose M here: the + module will be called microcode. + +config MICROCODE_OLD_INTERFACE + bool + depends on MICROCODE + default y + +config X86_MSR + tristate "/dev/cpu/*/msr - Model-specific register support" + help + This device gives privileged processes access to the x86 + Model-Specific Registers (MSRs). It is a character device with + major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. + MSR accesses are directed to a specific CPU on multi-processor + systems. + +config X86_CPUID + tristate "/dev/cpu/*/cpuid - CPU information support" + help + This device gives processes access to the x86 CPUID instruction to + be executed on a specific processor. It is a character device + with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to + /dev/cpu/31/cpuid. + +choice + prompt "High Memory Support" + default HIGHMEM4G if !X86_NUMAQ + default HIGHMEM64G if X86_NUMAQ + depends on X86_32 + +config NOHIGHMEM + bool "off" + depends on !X86_NUMAQ + ---help--- + Linux can use up to 64 Gigabytes of physical memory on x86 systems. + However, the address space of 32-bit x86 processors is only 4 + Gigabytes large. That means that, if you have a large amount of + physical memory, not all of it can be "permanently mapped" by the + kernel. The physical memory that's not permanently mapped is called + "high memory". + + If you are compiling a kernel which will never run on a machine with + more than 1 Gigabyte total physical RAM, answer "off" here (default + choice and suitable for most users). This will result in a "3GB/1GB" + split: 3GB are mapped so that each process sees a 3GB virtual memory + space and the remaining part of the 4GB virtual memory space is used + by the kernel to permanently map as much physical memory as + possible. + + If the machine has between 1 and 4 Gigabytes physical RAM, then + answer "4GB" here. + + If more than 4 Gigabytes is used then answer "64GB" here. This + selection turns Intel PAE (Physical Address Extension) mode on. + PAE implements 3-level paging on IA32 processors. PAE is fully + supported by Linux, PAE mode is implemented on all recent Intel + processors (Pentium Pro and better). NOTE: If you say "64GB" here, + then the kernel will not boot on CPUs that don't support PAE! + + The actual amount of total physical memory will either be + auto detected or can be forced by using a kernel command line option + such as "mem=256M". (Try "man bootparam" or see the documentation of + your boot loader (lilo or loadlin) about how to pass options to the + kernel at boot time.) + + If unsure, say "off". + +config HIGHMEM4G + bool "4GB" + depends on !X86_NUMAQ + help + Select this if you have a 32-bit processor and between 1 and 4 + gigabytes of physical RAM. + +config HIGHMEM64G + bool "64GB" + depends on !M386 && !M486 + select X86_PAE + help + Select this if you have a 32-bit processor and more than 4 + gigabytes of physical RAM. + +endchoice + +choice + depends on EXPERIMENTAL + prompt "Memory split" if EMBEDDED + default VMSPLIT_3G + depends on X86_32 + help + Select the desired split between kernel and user memory. + + If the address range available to the kernel is less than the + physical memory installed, the remaining memory will be available + as "high memory". Accessing high memory is a little more costly + than low memory, as it needs to be mapped into the kernel first. + Note that increasing the kernel address space limits the range + available to user programs, making the address space there + tighter. Selecting anything other than the default 3G/1G split + will also likely make your kernel incompatible with binary-only + kernel modules. + + If you are not absolutely sure what you are doing, leave this + option alone! + + config VMSPLIT_3G + bool "3G/1G user/kernel split" + config VMSPLIT_3G_OPT + depends on !X86_PAE + bool "3G/1G user/kernel split (for full 1G low memory)" + config VMSPLIT_2G + bool "2G/2G user/kernel split" + config VMSPLIT_2G_OPT + depends on !X86_PAE + bool "2G/2G user/kernel split (for full 2G low memory)" + config VMSPLIT_1G + bool "1G/3G user/kernel split" +endchoice + +config PAGE_OFFSET + hex + default 0xB0000000 if VMSPLIT_3G_OPT + default 0x80000000 if VMSPLIT_2G + default 0x78000000 if VMSPLIT_2G_OPT + default 0x40000000 if VMSPLIT_1G + default 0xC0000000 + depends on X86_32 + +config HIGHMEM + bool + depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) + default y + +config X86_PAE + bool "PAE (Physical Address Extension) Support" + default n + depends on X86_32 && !HIGHMEM4G + select RESOURCES_64BIT + help + PAE is required for NX support, and furthermore enables + larger swapspace support for non-overcommit purposes. It + has the cost of more pagetable lookup overhead, and also + consumes more pagetable space per process. + +# Common NUMA Features +config NUMA + bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)" + depends on SMP + depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL) + default n if X86_PC + default y if (X86_NUMAQ || X86_SUMMIT) + help + Enable NUMA (Non Uniform Memory Access) support. + The kernel will try to allocate memory used by a CPU on the + local memory controller of the CPU and add some more + NUMA awareness to the kernel. + + For i386 this is currently highly experimental and should be only + used for kernel development. It might also cause boot failures. + For x86_64 this is recommended on all multiprocessor Opteron systems. + If the system is EM64T, you should say N unless your system is + EM64T NUMA. + +comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" + depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) + +config K8_NUMA + bool "Old style AMD Opteron NUMA detection" + depends on X86_64 && NUMA && PCI + default y + help + Enable K8 NUMA node topology detection. You should say Y here if + you have a multi processor AMD K8 system. This uses an old + method to read the NUMA configuration directly from the builtin + Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA + instead, which also takes priority if both are compiled in. + +config X86_64_ACPI_NUMA + bool "ACPI NUMA detection" + depends on X86_64 && NUMA && ACPI && PCI + select ACPI_NUMA + default y + help + Enable ACPI SRAT based node topology detection. + +config NUMA_EMU + bool "NUMA emulation" + depends on X86_64 && NUMA + help + Enable NUMA emulation. A flat machine will be split + into virtual nodes when booted with "numa=fake=N", where N is the + number of nodes. This is only useful for debugging. + +config NODES_SHIFT + int + default "6" if X86_64 + default "4" if X86_NUMAQ + default "3" + depends on NEED_MULTIPLE_NODES + +config HAVE_ARCH_BOOTMEM_NODE + bool + depends on X86_32 && NUMA + default y + +config ARCH_HAVE_MEMORY_PRESENT + bool + depends on X86_32 && DISCONTIGMEM + default y + +config NEED_NODE_MEMMAP_SIZE + bool + depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) + default y + +config HAVE_ARCH_ALLOC_REMAP + bool + depends on X86_32 && NUMA + default y + +config ARCH_FLATMEM_ENABLE + def_bool y + depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA) + +config ARCH_DISCONTIGMEM_ENABLE + def_bool y + depends on NUMA + +config ARCH_DISCONTIGMEM_DEFAULT + def_bool y + depends on NUMA + +config ARCH_SPARSEMEM_ENABLE + def_bool y + depends on NUMA || (EXPERIMENTAL && (X86_PC || X86_64)) + select SPARSEMEM_STATIC if X86_32 + select SPARSEMEM_VMEMMAP_ENABLE if X86_64 + +config ARCH_SELECT_MEMORY_MODEL + def_bool y + depends on X86_32 && ARCH_SPARSEMEM_ENABLE + +config ARCH_MEMORY_PROBE + def_bool X86_64 + depends on MEMORY_HOTPLUG + +source "mm/Kconfig" + +config HIGHPTE + bool "Allocate 3rd-level pagetables from highmem" + depends on X86_32 && (HIGHMEM4G || HIGHMEM64G) + help + The VM uses one page table entry for each page of physical memory. + For systems with a lot of RAM, this can be wasteful of precious + low memory. Setting this option will put user-space page table + entries in high memory. + +config MATH_EMULATION + bool + prompt "Math emulation" if X86_32 + ---help--- + Linux can emulate a math coprocessor (used for floating point + operations) if you don't have one. 486DX and Pentium processors have + a math coprocessor built in, 486SX and 386 do not, unless you added + a 487DX or 387, respectively. (The messages during boot time can + give you some hints here ["man dmesg"].) Everyone needs either a + coprocessor or this emulation. + + If you don't have a math coprocessor, you need to say Y here; if you + say Y here even though you have a coprocessor, the coprocessor will + be used nevertheless. (This behavior can be changed with the kernel + command line option "no387", which comes handy if your coprocessor + is broken. Try "man bootparam" or see the documentation of your boot + loader (lilo or loadlin) about how to pass options to the kernel at + boot time.) This means that it is a good idea to say Y here if you + intend to use this kernel on different machines. + + More information about the internals of the Linux math coprocessor + emulation can be found in <file:arch/x86/math-emu/README>. + + If you are not sure, say Y; apart from resulting in a 66 KB bigger + kernel, it won't hurt. + +config MTRR + bool "MTRR (Memory Type Range Register) support" + ---help--- + On Intel P6 family processors (Pentium Pro, Pentium II and later) + the Memory Type Range Registers (MTRRs) may be used to control + processor access to memory ranges. This is most useful if you have + a video (VGA) card on a PCI or AGP bus. Enabling write-combining + allows bus write transfers to be combined into a larger transfer + before bursting over the PCI/AGP bus. This can increase performance + of image write operations 2.5 times or more. Saying Y here creates a + /proc/mtrr file which may be used to manipulate your processor's + MTRRs. Typically the X server should use this. + + This code has a reasonably generic interface so that similar + control registers on other processors can be easily supported + as well: + + The Cyrix 6x86, 6x86MX and M II processors have Address Range + Registers (ARRs) which provide a similar functionality to MTRRs. For + these, the ARRs are used to emulate the MTRRs. + The AMD K6-2 (stepping 8 and above) and K6-3 processors have two + MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing + write-combining. All of these processors are supported by this code + and it makes sense to say Y here if you have one of them. + + Saying Y here also fixes a problem with buggy SMP BIOSes which only + set the MTRRs for the boot CPU and not for the secondary CPUs. This + can lead to all sorts of problems, so it's good to say Y here. + + You can safely say Y even if your machine doesn't have MTRRs, you'll + just add about 9 KB to your kernel. + + See <file:Documentation/mtrr.txt> for more information. + +config EFI + bool "Boot from EFI support" + depends on X86_32 && ACPI + default n + ---help--- + This enables the kernel to boot on EFI platforms using + system configuration information passed to it from the firmware. + This also enables the kernel to use any EFI runtime services that are + available (such as the EFI variable services). + + This option is only useful on systems that have EFI firmware + and will result in a kernel image that is ~8k larger. In addition, + you must use the latest ELILO loader available at + <http://elilo.sourceforge.net> in order to take advantage of + kernel initialization using EFI information (neither GRUB nor LILO know + anything about EFI). However, even with this option, the resultant + kernel should continue to boot on existing non-EFI platforms. + +config IRQBALANCE + bool "Enable kernel irq balancing" + depends on X86_32 && SMP && X86_IO_APIC + default y + help + The default yes will allow the kernel to do irq load balancing. + Saying no will keep the kernel from doing irq load balancing. + +# turning this on wastes a bunch of space. +# Summit needs it only when NUMA is on +config BOOT_IOREMAP + bool + depends on X86_32 && (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI)) + default y + +config SECCOMP + bool "Enable seccomp to safely compute untrusted bytecode" + depends on PROC_FS + default y + help + This kernel feature is useful for number crunching applications + that may need to compute untrusted bytecode during their + execution. By using pipes or other transports made available to + the process as file descriptors supporting the read/write + syscalls, it's possible to isolate those applications in + their own address space using seccomp. Once seccomp is + enabled via /proc/<pid>/seccomp, it cannot be disabled + and the task is only allowed to execute a few safe syscalls + defined by each seccomp mode. + + If unsure, say Y. Only embedded should say N here. + +config CC_STACKPROTECTOR + bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" + depends on X86_64 && EXPERIMENTAL + help + This option turns on the -fstack-protector GCC feature. This + feature puts, at the beginning of critical functions, a canary + value on the stack just before the return address, and validates + the value just before actually returning. Stack based buffer + overflows (that need to overwrite this return address) now also + overwrite the canary, which gets detected and the attack is then + neutralized via a kernel panic. + + This feature requires gcc version 4.2 or above, or a distribution + gcc with the feature backported. Older versions are automatically + detected and for those versions, this configuration option is ignored. + +config CC_STACKPROTECTOR_ALL + bool "Use stack-protector for all functions" + depends on CC_STACKPROTECTOR + help + Normally, GCC only inserts the canary value protection for + functions that use large-ish on-stack buffers. By enabling + this option, GCC will be asked to do this for ALL functions. + +source kernel/Kconfig.hz + +config KEXEC + bool "kexec system call" + help + kexec is a system call that implements the ability to shutdown your + current kernel, and to start another kernel. It is like a reboot + but it is independent of the system firmware. And like a reboot + you can start any kernel with it, not just Linux. + + The name comes from the similarity to the exec system call. + + It is an ongoing process to be certain the hardware in a machine + is properly shutdown, so do not be surprised if this code does not + initially work for you. It may help to enable device hotplugging + support. As of this writing the exact hardware interface is + strongly in flux, so no good recommendation can be made. + +config CRASH_DUMP + bool "kernel crash dumps (EXPERIMENTAL)" + depends on EXPERIMENTAL + depends on X86_64 || (X86_32 && HIGHMEM) + help + Generate crash dump after being started by kexec. + This should be normally only set in special crash dump kernels + which are loaded in the main kernel with kexec-tools into + a specially reserved region and then later executed after + a crash by kdump/kexec. The crash dump kernel must be compiled + to a memory address not used by the main kernel or BIOS using + PHYSICAL_START, or it must be built as a relocatable image + (CONFIG_RELOCATABLE=y). + For more details see Documentation/kdump/kdump.txt + +config PHYSICAL_START + hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) + default "0x1000000" if X86_NUMAQ + default "0x200000" if X86_64 + default "0x100000" + help + This gives the physical address where the kernel is loaded. + + If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then + bzImage will decompress itself to above physical address and + run from there. Otherwise, bzImage will run from the address where + it has been loaded by the boot loader and will ignore above physical + address. + + In normal kdump cases one does not have to set/change this option + as now bzImage can be compiled as a completely relocatable image + (CONFIG_RELOCATABLE=y) and be used to load and run from a different + address. This option is mainly useful for the folks who don't want + to use a bzImage for capturing the crash dump and want to use a + vmlinux instead. vmlinux is not relocatable hence a kernel needs + to be specifically compiled to run from a specific memory area + (normally a reserved region) and this option comes handy. + + So if you are using bzImage for capturing the crash dump, leave + the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y. + Otherwise if you plan to use vmlinux for capturing the crash dump + change this value to start of the reserved region (Typically 16MB + 0x1000000). In other words, it can be set based on the "X" value as + specified in the "crashkernel=YM@XM" command line boot parameter + passed to the panic-ed kernel. Typically this parameter is set as + crashkernel=64M@16M. Please take a look at + Documentation/kdump/kdump.txt for more details about crash dumps. + + Usage of bzImage for capturing the crash dump is recommended as + one does not have to build two kernels. Same kernel can be used + as production kernel and capture kernel. Above option should have + gone away after relocatable bzImage support is introduced. But it + is present because there are users out there who continue to use + vmlinux for dump capture. This option should go away down the + line. + + Don't change this unless you know what you are doing. + +config RELOCATABLE + bool "Build a relocatable kernel (EXPERIMENTAL)" + depends on EXPERIMENTAL + help + This builds a kernel image that retains relocation information + so it can be loaded someplace besides the default 1MB. + The relocations tend to make the kernel binary about 10% larger, + but are discarded at runtime. + + One use is for the kexec on panic case where the recovery kernel + must live at a different physical address than the primary + kernel. + + Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address + it has been loaded at and the compile time physical address + (CONFIG_PHYSICAL_START) is ignored. + +config PHYSICAL_ALIGN + hex + prompt "Alignment value to which kernel should be aligned" if X86_32 + default "0x100000" if X86_32 + default "0x200000" if X86_64 + range 0x2000 0x400000 + help + This value puts the alignment restrictions on physical address + where kernel is loaded and run from. Kernel is compiled for an + address which meets above alignment restriction. + + If bootloader loads the kernel at a non-aligned address and + CONFIG_RELOCATABLE is set, kernel will move itself to nearest + address aligned to above value and run from there. + + If bootloader loads the kernel at a non-aligned address and + CONFIG_RELOCATABLE is not set, kernel will ignore the run time + load address and decompress itself to the address it has been + compiled for and run from there. The address for which kernel is + compiled already meets above alignment restrictions. Hence the + end result is that kernel runs from a physical address meeting + above alignment restrictions. + + Don't change this unless you know what you are doing. + +config HOTPLUG_CPU + bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)" + depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER + ---help--- + Say Y here to experiment with turning CPUs off and on, and to + enable suspend on SMP systems. CPUs can be controlled through + /sys/devices/system/cpu. + Say N if you want to disable CPU hotplug and don't need to + suspend. + +config COMPAT_VDSO + bool "Compat VDSO support" + default y + depends on X86_32 + help + Map the VDSO to the predictable old-style address too. + ---help--- + Say N here if you are running a sufficiently recent glibc + version (2.3.3 or later), to remove the high-mapped + VDSO mapping and to exclusively use the randomized VDSO. + + If unsure, say Y. + +endmenu + +config ARCH_ENABLE_MEMORY_HOTPLUG + def_bool y + depends on X86_64 || (X86_32 && HIGHMEM) + +config MEMORY_HOTPLUG_RESERVE + def_bool X86_64 + depends on (MEMORY_HOTPLUG && DISCONTIGMEM) + +config HAVE_ARCH_EARLY_PFN_TO_NID + def_bool X86_64 + depends on NUMA + +config OUT_OF_LINE_PFN_TO_PAGE + def_bool X86_64 + depends on DISCONTIGMEM menu "Power management options" depends on !X86_VOYAGER |
