Linux build options

The Linux kernel has configurable build options that enable specific features to be added or removed from the kernel during initial compilation. Customized default parameters may also be configured during this time.

The kernel build options can now be configured:

Experimental Kernel Options

EXPERIMENTAL

This allows inclusion of development, incomplete or obsolete code/drivers

General Setup Options

LOCALVERSION

This provides a facility to add additional version information to the end of the kernel version string.

LOCALVERSION_AUTO

SWAP

Support for paging of anonymous memory

SYSVIPC

This provides support for inter-process communications.

IPC_NS

This provides support for IPC_NS IPC Namespaces

BSD_PROCESS_ACCT

This allows the kernel to write process information to a file.

TASKSTATS

Provides the facility to export task/process statistics through netlink.

UTS_NS

This allows multiple virtual hostnames for subprocesses.

AUDIT

This provides a gateway from the kernel to security auditing processes.

IKCONFIG

This provides kernel .config support.

LOG_BUF_SHIFT

CPUSETS

This provides the facilty for the system administrator to restrict the number of processors and memory resources that a process or set of processes may use, allowing a division of CPUs and memory resources within a larger system.

SYSFS_DEPRECATED

This option creates unstable and obsoleted device- and bus- .

Standard Kernel Features for Small (EMBEDDED) Systems

UID16

This enables legacy 16 bit syscall wrappers.

SYS_SYSCTL

The legacy sys_sysctl system uses binary pathnames, and has been superceded by the /proc filesystem.

KALLSYMS

This allows the kernel to display symbolic crash information and stack traces.

HOTPLUG

This enables support for hot pluggable devices.

PRINTK

This allows the kernel to print messages. Without this option, the message strings are removed and the kernel is silent and difficult to debug. (This option should only be disabled on embedded systems.)

BUG

This enables support for BUG() and WARN() system calls. Without this facility, the kernel may ignore fatal errors. (This option should only be disabled on embedded systems.)

ELF_CORE

This enables core dumps to be produced.

BASE_FULL

This option enables enhanced system performance, but uses extra system memory.

FUTEX

This option enables fast userspace mutex support and is required by .

ANON_INODES

This option enables anonymous inodes to be used for pseudofiles.

EPOLL

This option enable eventpoll system calls.

SIGNALFD

This option enables signals to be received on a file descriptor.

EVENTFD

This option enables the eventfd system call to receive kernel and userspace notifications.

SHMEM

The shmem filesystem is used to manage shared memory resources. It is used by swap and is mapped to userspace by tmpfs. If this option is disabled, shmem and tmpfs are replaced by much simpler ramfs code.

VM_EVENT_COUNTERS

This option enables VM events to be shown in !/proc/vmstat. If the option is disabled, only page counts are shown.

SLAB

This option determines the memory management model used by the kernel. The default allocator is efficient, but has a memory overhead to manage the system queues.

SLAB allocator options:

1. SLAB (Advanced Allocator) (SLAB)
2. SLUB (Unqueued Allocator) (SLUB)
3. SLOB (Simple Allocator) (SLOB)

Kernel Loadable Module Support Options

MODULES

This option allows the kernel to use loadable modules.

MODULES_UNLOAD

MODVERSION

This provides MODVERSION Module Versioning support

MODULE_SRCVERSION_ALL

Source checksum for all modules (MODULE_SRCVERSION_ALL)

KMOD

Automatic kernel module loading (KMOD)

Block Layer Support Options

The block layer is used by SCSI and USB devices and various filesystems (such as EXT3), and should be enabled.

LBD

This option adds support for large disks or raid arrays (with a capacity in excess of 2Tb).

BLK_DEV_IO_TRACE

This option enables monitoring of traffic on block device queues.

LSF

This option provides support for large single files (larger than 2Tb).

IO Schedulers

The anticipatory IO scheduler is a large and advanced IO scheduler, compared to the deadline IO scheduler. The CFQ IO scheduler is the default system scheduler.

IOSCHED_NOOP

This is a minimal scheduler for non-disk based systems or specialized environments that require only minimal kernel assistance. This option was not available during the current kernel build, so may have been made obsolete.

IOSCHED_AS

The anticipatory IO scheduler is a large and advanced disk IO scheduler.

IOSCHED_DEADLINE

The deadline IO sceduler is a simple and compact scheduler with good performance.

IOSCHED_CFQ

The CFQ IO scheduler tried to distribute bandwidth equally amongst all processes in the system.

Processor type and features

NO_HZ

This parameter causes the timer interrupt to only run as required.

HIGH_RES_TIMERS

This parameter is only supported on systems that have appropriate hardware support.

Symmetric Multi-Processor Support

This SMP options enables the kernel to use multiple processors. This may prevent the kernel from working on some single processor machines.

Subarchitecture Type

This option specifies the specific architecture of the build target.

Processor family

This option ensures that the kernel will compile using appropriate instruction sets.

X86_GENERIC

This includes some processor specific modifications for generic kernel builds.

HPET_TIMER

This allows the system to use an alternative timing chip available on some motherboards.

Premption Model

The premption model determines how performance can be improved by allowing premption of a low priority process during a kernel system call.

PREEMPT_NONE

This is the traditional preemption model geared towards maximizing throughput. It provides good latency, though scheduling delays are sometimes possible. This option allows the raw processing power of the kernel to be used to used to its full potential. This option should be selected for server or scientific application computers.

PREEMPT_VOLUNTARY

This option adds explicit preemption points to the kernel code. This reduces rescheduling latency and improves application responsiveness at the cost of kernel throughput. This option speeds up reaction to interactive events by allowing premption of low priority events (even if they are within the kernel making a system call).

PREEMPT

This option reduces kernel latency by allowing preemption on all non-critical kernel code, allowing preemtion of low priority events (even if they are within the kernel making a system call). This allows applications to run more smoothly under load, but produces a slightly lower throughput, and increases the kernel runtime overhead.

PREEMPT_BKL

This option allow premption of the big kernel lock, and is useful for desktop systems.

APIC Advanced Processor Interupt Controller

This enables the use of an on chip APIC Advanced Processor Interrupt Controller

X86_MCE Machine Check Exception

This allows the kernel to react to machine check exception signals, such as CPU overvoltage, or other such signals.

X86_MCE_NONFATAL

This enables timed register polling for MCE registers and is effective for certain processors only.

VM86

This option enables 16 bit virtual machine support required by and certain X video drivers.

Laptop Support

TOSHIBA

Toshiba Laptop support (TOSHIBA)

I8K

Dell laptop support (I8K)

This option provides fixups that prevent system hangs that occurs with some motherboards during reboot.

CPU Specific Features

These options enable various Intel specific features that can be utilized by the kernel.

MICROCODE

/dev/cpu/microcode - Intel IA32 CPU microcode support (MICROCODE)

X86_MSR

/dev/cpu/*/msr - Model-specific register support (X86_MSR)

X86_CPUID

/dev/cpu/*/cpuid - CPU information support (X86_CPUID)

Firmware Drivers

EDD

This option enables real mode BIOS service calls to determine the boot disk and only a few disk drive controllers.

DELL_RDU

This option enables BIOS updates on Dell computers.

BIOS update support for DELL systems via sysfs (DELL_RDU)

DCDBAS

DELL Systems Management Base Driver (DCDBAS)

High Memory Support

High Memory Support options can be enabled on computers with more than 1Gb RAM.

Maths Emulation

Pentium compatible processors have an on-chip numeric coprocessor, so no emulation is required on these newer machines.

MTRR Memory Type Range Register

The MTRR Memory Type Range Register increases the speed of video memory writes by about 2.5 times on AMD K6, Cyrix 686, Pentium II and higher machines. This can be enabled on CPUs without this feature.

EFI EFI support

This is for EFI specific platforms.

SECCOMP

This option enables applications to run in their own private address space using restricted system calls.

Timer Frequency

This option sets the kernel base time frequency. The traditional base frequency is 100Hz.

KEXEC

This option provides the facility for the kernel to shutdown and start another kernel and may not work on all computers.

PHYSICAL_START

This option configures the physical start address for the kernel to be loaded.

Physical address where the kernel is loaded (PHYSICAL_START) :

PHYSICAL_ALIGN

This option configures the start address alignment value for the kernel to be loaded.

Alignment value to where the kernel should be aligned (PHYSICAL_ALIGN) :

COMPAT_VDSO

This enables the library to call memory mapped VDSO code, rather than INT 0x80

PM Power Management Options

These options enables APM or ACPI to be used by the kernel.

LEGACY_PM

This option provides support for a deprecated API application interface.

PM_DEBUG

This kernel build option causes the configurator to provide debug options used for debugging the Power Management Subsystem.

PM_DEPRECATED

Driver model /sys/devices/.../power/state files (PM_DEPRECATED)

SOFTWARE_SUSPEND

Software suspend (Hibernation) (SOFTWARE_SUSPEND)

ACPI ACPI Support

ACPI Support (ACPI)

ACPI_SLEEP

Sleep States (ACPI_SLEEP)

ACPI_PROCFS

Procfs interface (Deprecated) (ACPI_PROCFS)

ACPI_AC

AC Adapter (ACPI_AC)

ACPI_BATTERY

Battery (ACPI_BATTERY)

ACPI_BUTTON

Button (ACPI_BUTTON)

ACPI_FAN

Fan (ACPI_FAN)

ACPI_PROCESSOR

Processor (ACPI_PROCESSOR)

ACPI_THERMAL

Thermal Zone (ACPI_THERMAL)

ACPI_ASUS

ASUS/Medion Laptop Extras (ACPI_ASUS) (Deprecated)

ACPI_TOSHIBA

Toshiba Laptop Extras (ACPI_TOSHIBA)

Disable ACPI for old systems

Disable ACPI for systems before 1st Jan this year :

ACPI_DEBUG

ACPI Debug Statements (ACPI_DEBUG)

ACPI_RELAXED_AML

This relaxes checking of AML information. This option was not provided with the current build and may have been made obsolete.

X86_PM_TIMER

The power management timer is available on most systems, even those with blacklisted ACPI. Some systems require this timer for normal operation so this option should be enabled.

APM Advanced Power Management

The Advanced Power Management system does not operate correctly on most computers. It is recommended that this option is disabled.

CPU_FREQ CPU Frequency scaling

This allows the CPU frequency to be changed by software. Not all CPUs support this.

Kernel Bus Options

PCI

This enables support for the PCI bus.

PCI Access Mode

The PCI bus can be accessed directly by the kernel:

PCIEPORTBUS

PCI_LEGACY_PROC

This option provides support for the legacy /proc/pci interface. This option was not offered during the current kernel build so it may have been obsoleted.

PCI_NAMES

This option changes the way that PCI devices appear in the legacy /proc/pci interface. This option was not provided with the current kernel build and may have been made obsolete.

PCI_DEBUG

ISA

This option enables support for the ISA bus.

EISA

This option enables support for EISA devices.

Microchannel Architecture

This option enables support for Microchannel Architecture devices.

SCx200

This option provides support for the National Semiconductors Geode processor

PCMCIA/CardBus

This option provides support for PCMCIA card slots.

PCMCIA/CardBus support (PCCARD) m

PCMCIA_DEBUG

PCMCIA

This option provides support for 16 bit PCMCIA devices.

PCMCIA_IOCTL

This option provides support for the obsoleted PCMCIA_IOCTL interface. It is required by cardmgr and cartctl to function properly.

CARDBUS

Some PCMCIA cards are actually 32 bit CARDBUS cards. This option should be enabled to allow 32 bit devices to operate. Most PCMCIA bridges provide Yenta compatible CARDBUS slots.

YENTA

YENTA_02

YENTA_ROCOH

YENTA_TI

YENTA_TOSHIBA

PD6729

The Cirrus PD6729 bridge is found in some older laptop computers and PCMCIA card readers.

I82092

This option provides support for the Intel I82092AA bridge found on Intel Evaluation boards.

I82365

This option provides support for the Intel I82365 and register compatible boards.

TCIC

The TCIC hostbridge is found in some old laptop computers.

Kernel Executable File Format Options

BINFMT_ELF

This is the current format for executable binary files used on based platforms.

BINFMT_AOUT

This is the traditional format for executable binary files used on based platforms, and is used by some tiny Linux based distributions.

BINFMT_MISC

This option allows miscellaneous executable binary files to be executed by an appropriate handler, and may be used to pass executable files to a DOS emulation handler.

Kernel Network Support Options

NET Networking Support

This option enables networking support.

PACKET

This option enables applications to communicate directly with the network layer without an intermediate network protocol. This facility is required by network monitoring tools.

PACKET_MMAP

This option enables the packet driver to use memory mapped IO for faster communication. This is for use with fast ethernet cards providing network load mitigation or NAPI support.

UNIX

This option enables support for Unix domain sockets. These are used for interprocess and network communication.

XFRM_USER

This option provides support for the . This enables security to be provided at a network level, rather than at application level.

PFKEYv2

This options provides support for KAME compatible protocol stacks or security tools.

INET TCP/IP Networking

This option provides support for TCP networking.

IP_MULTICAST

This option enables broadcasting to several computers at the same time.

IP_ADVANCED_ROUTER

This provides support for IP forwarding and rp_filter anti-spoofing.

IP_PNP

This option provides support for kernel level IP protocol during boot, enabling for diskless systems.

NET_IPIP

This option provides IP over IP , which is almost certainly not required, except for specialized network configurations.

NET_IPGRE

This option provides Generic Routing Encapsulation allowing to be carried over existing infrastructure.

IP_MROUTE

This option enables routing of multicast address packets.

SYN_COOKIES

This option provides support.

INET_AH

Authentication Header transformation provides authenticity guarantee for transported packets by checksumming the packages using a cryptographic algorithm. If the checksum is found to be correct by the receiver, the receiver can be assured that the packet is not modified, and that the packet really originated from the reported sender (provided that the keys are only known by the sender and receiver).

INET_ESP

*Encapsulating Security Payload* provides encrypted data packets. This means that the packet is only readable by a host with the right decryption key.

INET_IPCOMP

*Payload Compression* provides data compression before a packet is encrypted. This is useful, because encrypted data generally does not compress as well as unencrypted data.

INET_XFRM_MODE_TRANSPORT

INET_XFRM_MODE_TUNNEL

INET_XFRM_MODE_BEET

INET_DIAG

TCP_CONG_ADVANCED

INET_ECN

This option was not provided with the current build and may have been made obsolete.

IPV6

This option provides support for IP6 protocol.

IP_VS

NETWORK_SECMARK

NETFILTER

This enables packet filtering for computers acting as a router.

BRIDGE

VLAN_8021Q

DECNET

LLC2

This provides support for PF_LLC sockets.

IPX

ATALK

NET_SCHED

This provides support for QoS Quality of Service, diffserv Differentiated Services and RSVP Resource Reservation Protocol.

NET_PKTGEN

This provides a packed generator for network stress testing.

Kernel Ham Radio Support Options
Kernel IRDA Support Options
Kernel Bluetooth Support Options
Kernel Wireless Support Options
Kernel Generic Device Driver Options

PREVENT_FIRMWARE_BUILD

This option prevents firmware from being rebuilt by the kernel.

FW_LOADER

This option enables userspace firmware loading by the kernel.

DEBUG_DRIVER

This option causes the kernel to output debugging messages relating to the driver core.

DEBUG_DEVRES

This option causes the kernel to output debugging messages relating to managed device resources.

CONNECTOR

This is a unified userspace/kernelspace linker that utilizes the netlink socket protocol.

MTD Memory Technology Device Support

This option provides support for , such as solid state storage media.

Kernel Parallel Port Options
Kernel Plug and Play Options
Kernel Block Device Options
Kernel IDE Device Options
Kernel SCSI Device Options
Kernel SATA and PATA Device Options
Kernel Legacy CDROM Options
Kernel Multi-Device RAID and LVM Options
Kernel Firewire Options
Kernel Legacy I20 Options
Kernel Macintosh Device Options
Kernel Network Device Options
Kernel 10Mbit and 100Mbit Network Device Options
Kernel ISA Network Device Options
Kernel PCI Network Device Options
Kernel 1000Mbit Network Device Options
Kernel Token Ring Network Device Options
Kernel Wireless Network Device Options
Kernel USB Network Device Options
Kernel PCMCIA Network Device Options
Kernel Wide Area Network Interface Options
Kernel Fibre Optic Network Interface Options
Kernel Parallel Line Interface Protocol Options
Kernel Point to Point Protocol Options
Kernel Serial Line Interface Protocol Options
Kernel Integrated Services Digital Network Options
Kernel Telephony Options
Kernel Input Device Options
Kernel Userland Interface Options
Kernel Keyboard Input Device Options
Kernel Mouse Input Device Options
Kernel Joystick Device Options
Kernel Tablet Device Options
Kernel Touchscreen Device Options
Kernel Miscellaneous Input Device Options
Kernel Hardware IO Port Options
Kernel Virtual Terminal Options
Kernel Serial Driver Options
Kernel Pseudo Terminal Options
Kernel Parallel Driver Options
Kernel Intelligent Platform Management Interface Options
Kernel Watchdog Timer Options
Kernel Hardware Random Number Generator Options
Kernel Non Volatile RAM and Hardware Clock Device Options
Kernel Speech Synthesizer Device Options
Kernel Programmable Logic Controller Device Options
Kernel Advanced Graphics Port Options
Kernel Direct Rendering Management Options
Kernel PCMCIA Character Device Options
Kernel Winmodem Device Options

MWAVE

This driver provides support for the ACP winmodem used on IBM Thinkpad 600E, 600, and 770 laptop computers.
Kernel General Purpose Input and Output Options
Kernel Event Timer Options
Kernel Trusted Platform Module Options
Kernel I2C Microcontroller Options
Kernel Serial Peripheral Interface Options
Kernel One Wire Interface Options
Kernel Hardware Monitoring Options
Kernel Multifunction Device Driver Options
Kernel Multimedia Device Options
Kernel Digital Video Broadcasting Options
Kernel Digital Audio Broadcasting Options
Kernel Backlight and Liquid Crystal Display Options
Kernel Display Device Options
Kernel Framebuffer Device Options
Kernel Console Display Driver Options
Kernel Sound Support Options
Kernel Advanced Linux Sound Architecture Options
Kernel Generic Sound Device Options
Kernel ISA Sound Device Options

SND_ADLIB

This driver provides support for Adlib FM cards.

SND_AD1816A

This driver provides support for Analog Devices AD1816A Soundport and compatible devices.

SND_AD1848

This driver provides support for an Analog Devices AD1848 or Cirrus Logic / Crystal Semiconductors CS4248 .

SND_ALS100

This driver provides support for devices based on Avance Logic ALS100, ALS110, ALS120 and ALS200 chips.

SND_AZT2320

This driver provides support for an Aztech Systems AZT2320 and compatible .

SND_CMI8330

This driver provides support for the !C-Media CMI8330 chip devices.

SND_CS4231

This driver provides support for Cirrus Logic and Crystal Semiconductors CS4231 chip devices.

SND_CS4232

This driver provides support for Cirrus Logic and Crystal Semiconductors CS4232 chip devices.

SND_CS4236

This driver provides support for CS4235,CS4236,CS4237B,CS4238B,CS4239 chips from Cirrus Logic and Crystal Semiconductors.

SND_DT019X

This driver provides support for Diamond Technologies DT-019X or Avance Logic ALS-007 devices.

SND_ES968

This driver provides support for ESS ES968 Audiodrive and devices.

SND_ES1688

This driver provides support for ESS ES688 and ES1688 Audiodrive and devices.

SND_ES18XX

This driver provides support for ESS ES1800 series and devices.

SND_SC6000

This driver provides support for Gallant SC-6000, Audio Excel DSP 16 and Zoltrix AV302 compatible devices.

SND_GUSCLASSIC

This driver provides support for a Gravis Ultrasound Classic .

SND_GUSEXTREME

This driver provides support for a Gravis Ultrasound Extreme .

SND_GUSMAX

This driver provides support for a Gravis Ultrasound MAX .

SND_INTERWAVE

This driver provides support for an AMD Interwave based such as Gravis UltraSound Plug & Play, STB !SoundRage32, !MED3210, Dynasonic Pro, or Panasonic !PCA761AW.

SND_INTERWAVE_STB

This driver provides support for an AMD Interwave based with a TEA6330T bass and treble regulator, such as an UltraSound !32-Pro.

SND_OPL3SA2

This driver provides support for Yamaha !OPL3-SA2 and !OPL3-SA3 compatible devices.

SND_OPTI92X_AD1848

This driver provides support for an Opti 82C92x or Opti 601 device using an AD1848 .

SND_OPTI92X_CS4231

This driver provides support for an Opti 82C92x device using a CS4231 .

SND_OPTI93X

This driver provides support for devices using an Opti 82C93x chip.

SND_MIRO

This driver provides support for !MiroSOUND !PCM1pro, !PCM12 and !PCM20 radio devices.

SND_SB8

This driver provides support for Sound Blaster 1.0, Sound Blaster 2.0 or Sound Blaster Pro (8-bit) compatible devices.

SND_SB16

This driver provides support for Sound Blaster 16 compatible devices, including versions.

SND_SBAWE

This driver provides support for Sound Blaster AWE 32 and Sound Blaster AWE 64 compatible devices, including versions.

SND_SB16_CSP

This driver provides support for the CSP which provides compression and decompression algorithms on an Sound Blaster 16 and AWE .

SND_SGALAXY

This driver provides support for an Aztech Sound Galaxy .

SND_SSCAPE

This driver provides support for an Ensoniq Soundscape

SND_WAVEFRONT

This driver provides support for Turtle Beach Maui, Tropez, Tropez+ devices using a Wavefront chip.

Kernel PCI Sound Device Options

Kernel USB Sound Device Options

SND_USB_AUDIO

This option provides support for audio and midi devices.

SND_USB_USX2Y

This driver supports Tascam audio and midi interface controllers !US-122, !US-224 and !US-428.

SND_USB_CAIAQ

This driver provides support Caiaq USB audio interfaces (Native Instruments !RigKontrol2, RigKontrol3, !Kore Controller, Audio Kontrol 1 and Audio 8 DJ)

Native Instruments USB audio devices (SND_USB_CAIAQ) n

Kernel PCMCIA Sound Device Options

Kernel System on Chip Sound Device Options

Kernel Open Sound System Options

SOUND_PRIME

This option provides support for legacy OSS Open Sound System drivers.

Kernel Human Interface Device Options

Kernel Universal Serial Bus Options

Kernel USB Device Class Driver Options

Kernel USB Imaging Device Options

Kernel USB Port Driver Options

Kernel USB Miscellaneous Driver Options

Kernel USB Gadget Driver Options

USB_GADGET

This option provides support for gadget side Host Controller Driver USB slave ports sometimes found in embedded applications.

Kernel Multimedia Card Driver Options

MMC

This option provides support for memory cards.

Kernel Light Emitting Diode Control Options

NEW_LED

This option allows control of supported additional LED Light Emitting Diode devices from userspace and from kernel event triggers. Note that this system does not control the standard keyboard lights, which are controlled via the input system.

Kernel Infiniband Driver Options

INFINIBAND

This option provides support for Infiniband devices.

Kernel Direct Memory Access Engine Options

DMA_ENGINE

This option provides support for Direct Memory Access Engine controllers.

Kernel Auxiliary Display Driver Options

Kernel General Filesystem Options

Kernel CDROM and DVD Filesystem Options

Kernel Microsoft Compatible Filesystem Options

MSDOS_FS

This driver provides support for FAT12 and FAT16 filesystems used on MSDOS partitions and MSDOS compatible floppy disks.

VFAT_FS

This driver provides support for FAT32 and long filenames on Microsoft Windows compatible partitions.

FAT_DEFAULT_CODEPAGE

This options sets the default codepage useb by the FAT filesystem.

FAT_DEFAULT_IOCHARSET

This option sets the default character set used by the FAT filesystem.

NTFS_FS

This driver provides support for NTFS filesystems.

Kernel Pseudo Filesystem Options

PROC_FS

This option enables the to creates a virtual file system containing information about the status of the system. This legacy option enlarges the kernel by a whopping 67K, but is currently required by several programs.

PROC_KCORE

This option provides a memory map !/proc/kcore which can be used for debugging. This virtual file appears to be the size of the system memory.

PROC_SYSCTL

This option provides the interface which allows kernel parameters or variables to be changed dynamically without requiring recompilation of the kernel or reboot of the system.

SYSFS

The virtual filesystem allows the to export interal objects, attributes and relationships. This enables useful information about the system (such as the devices on each bus and which driver each is bound to) to be obtained, and allows for tuning of devices and subsystems. Some system agents rely on the information in sysfs to operate, such as . The block subsystem uses to mound the root device. If sysfs is disabled, the boot device should be specified on the kernel command line. This may be disabled on systems.

TMPFS

This option provides a temporary file system which keeps files in virtual memory.

TMPFS_POSIX_ACL

This option provides support for permissions on the temporary filesystem.

HUGETLBFS

This option allows processes to use large pages, allowing memory defragmentation on high performance systems.

Kernel Miscellaneous Filesystem Options

Kernel Network Filesystem Options
Kernel Partition Options
Kernel Native Language Options
Kernel Hacking Options

PRINTK_TIME

This option causes timing information to be included in kernel output. This is useful for identifying long delays in kernel startup for debugging purposes.

ENABLE_MUST_CHECK

This option causes the kernel to output a warning: ignoring return value of 'foo', when attribute warn_unused_result is used.

MAGIC_SYSRQ

This option enables the system request key to save kernel information during a system crash, for debugging purposes.

UNUSED_SYMBOLS

This option exports obsolete symbols for kernel API for module debugging purposes.

DEBUG_FS

This option provides a virtual filesystem that can be used by kernel developers to place debugging files in.

HEADERS_CHECK

This option extracts the user-visible kernel headers during a kernel build, and runs basic sanity checks to ensure that exported files do not attempt to include files which were not exported. This is used by kernel developers who are modifying header files relevant to userspace.

DEBUG_KERNEL

This option provides debug options used by kernel driver developers.

DOUBLEFAULT

This option allows trapping of rare doublefault exceptions that would otherwise cause a system to silently reboot.

Kernel Security Options

Main Menu

See Also

Main Menu