11da177e4SLinus Torvaldsmenu "Code maturity level options" 21da177e4SLinus Torvalds 31da177e4SLinus Torvaldsconfig EXPERIMENTAL 41da177e4SLinus Torvalds bool "Prompt for development and/or incomplete code/drivers" 51da177e4SLinus Torvalds ---help--- 61da177e4SLinus Torvalds Some of the various things that Linux supports (such as network 71da177e4SLinus Torvalds drivers, file systems, network protocols, etc.) can be in a state 81da177e4SLinus Torvalds of development where the functionality, stability, or the level of 91da177e4SLinus Torvalds testing is not yet high enough for general use. This is usually 101da177e4SLinus Torvalds known as the "alpha-test" phase among developers. If a feature is 111da177e4SLinus Torvalds currently in alpha-test, then the developers usually discourage 121da177e4SLinus Torvalds uninformed widespread use of this feature by the general public to 131da177e4SLinus Torvalds avoid "Why doesn't this work?" type mail messages. However, active 141da177e4SLinus Torvalds testing and use of these systems is welcomed. Just be aware that it 151da177e4SLinus Torvalds may not meet the normal level of reliability or it may fail to work 161da177e4SLinus Torvalds in some special cases. Detailed bug reports from people familiar 171da177e4SLinus Torvalds with the kernel internals are usually welcomed by the developers 181da177e4SLinus Torvalds (before submitting bug reports, please read the documents 191da177e4SLinus Torvalds <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, 201da177e4SLinus Torvalds <file:Documentation/BUG-HUNTING>, and 211da177e4SLinus Torvalds <file:Documentation/oops-tracing.txt> in the kernel source). 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds This option will also make obsoleted drivers available. These are 241da177e4SLinus Torvalds drivers that have been replaced by something else, and/or are 251da177e4SLinus Torvalds scheduled to be removed in a future kernel release. 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds Unless you intend to help test and develop a feature or driver that 281da177e4SLinus Torvalds falls into this category, or you have a situation that requires 291da177e4SLinus Torvalds using these features, you should probably say N here, which will 301da177e4SLinus Torvalds cause the configurator to present you with fewer choices. If 311da177e4SLinus Torvalds you say Y here, you will be offered the choice of using features or 321da177e4SLinus Torvalds drivers that are currently considered to be in the alpha-test phase. 331da177e4SLinus Torvalds 341da177e4SLinus Torvaldsconfig BROKEN 351da177e4SLinus Torvalds bool 361da177e4SLinus Torvalds 371da177e4SLinus Torvaldsconfig BROKEN_ON_SMP 381da177e4SLinus Torvalds bool 391da177e4SLinus Torvalds depends on BROKEN || !SMP 401da177e4SLinus Torvalds default y 411da177e4SLinus Torvalds 421da177e4SLinus Torvaldsconfig LOCK_KERNEL 431da177e4SLinus Torvalds bool 441da177e4SLinus Torvalds depends on SMP || PREEMPT 451da177e4SLinus Torvalds default y 461da177e4SLinus Torvalds 471da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT 481da177e4SLinus Torvalds int 491da177e4SLinus Torvalds default 32 if !USERMODE 501da177e4SLinus Torvalds default 128 if USERMODE 511da177e4SLinus Torvalds help 5234ad92c2SRandy Dunlap Maximum of each of the number of arguments and environment 5334ad92c2SRandy Dunlap variables passed to init from the kernel command line. 541da177e4SLinus Torvalds 551da177e4SLinus Torvaldsendmenu 561da177e4SLinus Torvalds 571da177e4SLinus Torvaldsmenu "General setup" 581da177e4SLinus Torvalds 591da177e4SLinus Torvaldsconfig LOCALVERSION 601da177e4SLinus Torvalds string "Local version - append to kernel release" 611da177e4SLinus Torvalds help 621da177e4SLinus Torvalds Append an extra string to the end of your kernel version. 631da177e4SLinus Torvalds This will show up when you type uname, for example. 641da177e4SLinus Torvalds The string you set here will be appended after the contents of 651da177e4SLinus Torvalds any files with a filename matching localversion* in your 661da177e4SLinus Torvalds object and source tree, in that order. Your total string can 671da177e4SLinus Torvalds be a maximum of 64 characters. 681da177e4SLinus Torvalds 69aaebf433SRyan Andersonconfig LOCALVERSION_AUTO 70aaebf433SRyan Anderson bool "Automatically append version information to the version string" 71aaebf433SRyan Anderson default y 72aaebf433SRyan Anderson help 73aaebf433SRyan Anderson This will try to automatically determine if the current tree is a 74aaebf433SRyan Anderson release tree by looking for git tags that 75aaebf433SRyan Anderson belong to the current top of tree revision. 76aaebf433SRyan Anderson 77aaebf433SRyan Anderson A string of the format -gxxxxxxxx will be added to the localversion 78aaebf433SRyan Anderson if a git based tree is found. The string generated by this will be 79aaebf433SRyan Anderson appended after any matching localversion* files, and after the value 80aaebf433SRyan Anderson set in CONFIG_LOCALVERSION 81aaebf433SRyan Anderson 82aaebf433SRyan Anderson Note: This requires Perl, and a git repository, but not necessarily 83aaebf433SRyan Anderson the git or cogito tools to be installed. 84aaebf433SRyan Anderson 851da177e4SLinus Torvaldsconfig SWAP 861da177e4SLinus Torvalds bool "Support for paging of anonymous memory (swap)" 871da177e4SLinus Torvalds depends on MMU 881da177e4SLinus Torvalds default y 891da177e4SLinus Torvalds help 901da177e4SLinus Torvalds This option allows you to choose whether you want to have support 911da177e4SLinus Torvalds for so called swap devices or swap files in your kernel that are 921da177e4SLinus Torvalds used to provide more virtual memory than the actual RAM present 931da177e4SLinus Torvalds in your computer. If unsure say Y. 941da177e4SLinus Torvalds 951da177e4SLinus Torvaldsconfig SYSVIPC 961da177e4SLinus Torvalds bool "System V IPC" 971da177e4SLinus Torvalds ---help--- 981da177e4SLinus Torvalds Inter Process Communication is a suite of library functions and 991da177e4SLinus Torvalds system calls which let processes (running programs) synchronize and 1001da177e4SLinus Torvalds exchange information. It is generally considered to be a good thing, 1011da177e4SLinus Torvalds and some programs won't run unless you say Y here. In particular, if 1021da177e4SLinus Torvalds you want to run the DOS emulator dosemu under Linux (read the 1031da177e4SLinus Torvalds DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), 1041da177e4SLinus Torvalds you'll need to say Y here. 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds You can find documentation about IPC with "info ipc" and also in 1071da177e4SLinus Torvalds section 6.4 of the Linux Programmer's Guide, available from 1081da177e4SLinus Torvalds <http://www.tldp.org/guides.html>. 1091da177e4SLinus Torvalds 1101da177e4SLinus Torvaldsconfig POSIX_MQUEUE 1111da177e4SLinus Torvalds bool "POSIX Message Queues" 1121da177e4SLinus Torvalds depends on NET && EXPERIMENTAL 1131da177e4SLinus Torvalds ---help--- 1141da177e4SLinus Torvalds POSIX variant of message queues is a part of IPC. In POSIX message 1151da177e4SLinus Torvalds queues every message has a priority which decides about succession 1161da177e4SLinus Torvalds of receiving it by a process. If you want to compile and run 1171da177e4SLinus Torvalds programs written e.g. for Solaris with use of its POSIX message 1181da177e4SLinus Torvalds queues (functions mq_*) say Y here. To use this feature you will 1191da177e4SLinus Torvalds also need mqueue library, available from 1201da177e4SLinus Torvalds <http://www.mat.uni.torun.pl/~wrona/posix_ipc/> 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds POSIX message queues are visible as a filesystem called 'mqueue' 1231da177e4SLinus Torvalds and can be mounted somewhere if you want to do filesystem 1241da177e4SLinus Torvalds operations on message queues. 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds If unsure, say Y. 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT 1291da177e4SLinus Torvalds bool "BSD Process Accounting" 1301da177e4SLinus Torvalds help 1311da177e4SLinus Torvalds If you say Y here, a user level program will be able to instruct the 1321da177e4SLinus Torvalds kernel (via a special system call) to write process accounting 1331da177e4SLinus Torvalds information to a file: whenever a process exits, information about 1341da177e4SLinus Torvalds that process will be appended to the file by the kernel. The 1351da177e4SLinus Torvalds information includes things such as creation time, owning user, 1361da177e4SLinus Torvalds command name, memory usage, controlling terminal etc. (the complete 1371da177e4SLinus Torvalds list is in the struct acct in <file:include/linux/acct.h>). It is 1381da177e4SLinus Torvalds up to the user level program to do useful things with this 1391da177e4SLinus Torvalds information. This is generally a good idea, so say Y. 1401da177e4SLinus Torvalds 1411da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT_V3 1421da177e4SLinus Torvalds bool "BSD Process Accounting version 3 file format" 1431da177e4SLinus Torvalds depends on BSD_PROCESS_ACCT 1441da177e4SLinus Torvalds default n 1451da177e4SLinus Torvalds help 1461da177e4SLinus Torvalds If you say Y here, the process accounting information is written 1471da177e4SLinus Torvalds in a new file format that also logs the process IDs of each 1481da177e4SLinus Torvalds process and it's parent. Note that this file format is incompatible 1491da177e4SLinus Torvalds with previous v0/v1/v2 file formats, so you will need updated tools 1501da177e4SLinus Torvalds for processing it. A preliminary version of these tools is available 1511da177e4SLinus Torvalds at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. 1521da177e4SLinus Torvalds 1531da177e4SLinus Torvaldsconfig SYSCTL 1541da177e4SLinus Torvalds bool "Sysctl support" 1551da177e4SLinus Torvalds ---help--- 1561da177e4SLinus Torvalds The sysctl interface provides a means of dynamically changing 1571da177e4SLinus Torvalds certain kernel parameters and variables on the fly without requiring 1581da177e4SLinus Torvalds a recompile of the kernel or reboot of the system. The primary 1591da177e4SLinus Torvalds interface consists of a system call, but if you say Y to "/proc 1601da177e4SLinus Torvalds file system support", a tree of modifiable sysctl entries will be 1611da177e4SLinus Torvalds generated beneath the /proc/sys directory. They are explained in the 1621da177e4SLinus Torvalds files in <file:Documentation/sysctl/>. Note that enabling this 1631da177e4SLinus Torvalds option will enlarge the kernel by at least 8 KB. 1641da177e4SLinus Torvalds 1651da177e4SLinus Torvalds As it is generally a good thing, you should say Y here unless 1661da177e4SLinus Torvalds building a kernel for install/rescue disks or your system is very 1671da177e4SLinus Torvalds limited in memory. 1681da177e4SLinus Torvalds 1691da177e4SLinus Torvaldsconfig AUDIT 1701da177e4SLinus Torvalds bool "Auditing support" 171804a6a49SChris Wright depends on NET 1721da177e4SLinus Torvalds help 1731da177e4SLinus Torvalds Enable auditing infrastructure that can be used with another 1741da177e4SLinus Torvalds kernel subsystem, such as SELinux (which requires this for 1751da177e4SLinus Torvalds logging of avc messages output). Does not do system-call 1761da177e4SLinus Torvalds auditing without CONFIG_AUDITSYSCALL. 1771da177e4SLinus Torvalds 1781da177e4SLinus Torvaldsconfig AUDITSYSCALL 1791da177e4SLinus Torvalds bool "Enable system-call auditing support" 180347a8dc3SMartin Schwidefsky depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) 1811da177e4SLinus Torvalds default y if SECURITY_SELINUX 1821da177e4SLinus Torvalds help 1831da177e4SLinus Torvalds Enable low-overhead system-call auditing infrastructure that 1841da177e4SLinus Torvalds can be used independently or with another kernel subsystem, 185*f368c07dSAmy Griffis such as SELinux. To use audit's filesystem watch feature, please 186*f368c07dSAmy Griffis ensure that INOTIFY is configured. 1871da177e4SLinus Torvalds 1881da177e4SLinus Torvaldsconfig IKCONFIG 1891da177e4SLinus Torvalds bool "Kernel .config support" 1901da177e4SLinus Torvalds ---help--- 1911da177e4SLinus Torvalds This option enables the complete Linux kernel ".config" file 1921da177e4SLinus Torvalds contents to be saved in the kernel. It provides documentation 1931da177e4SLinus Torvalds of which kernel options are used in a running kernel or in an 1941da177e4SLinus Torvalds on-disk kernel. This information can be extracted from the kernel 1951da177e4SLinus Torvalds image file with the script scripts/extract-ikconfig and used as 1961da177e4SLinus Torvalds input to rebuild the current kernel or to build another kernel. 1971da177e4SLinus Torvalds It can also be extracted from a running kernel by reading 1981da177e4SLinus Torvalds /proc/config.gz if enabled (below). 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvaldsconfig IKCONFIG_PROC 2011da177e4SLinus Torvalds bool "Enable access to .config through /proc/config.gz" 2021da177e4SLinus Torvalds depends on IKCONFIG && PROC_FS 2031da177e4SLinus Torvalds ---help--- 2041da177e4SLinus Torvalds This option enables access to the kernel configuration file 2051da177e4SLinus Torvalds through /proc/config.gz. 2061da177e4SLinus Torvalds 2071da177e4SLinus Torvaldsconfig CPUSETS 2081da177e4SLinus Torvalds bool "Cpuset support" 2091da177e4SLinus Torvalds depends on SMP 2101da177e4SLinus Torvalds help 211d9fd8a6dSRandy Dunlap This option will let you create and manage CPUSETs which 2121da177e4SLinus Torvalds allow dynamically partitioning a system into sets of CPUs and 2131da177e4SLinus Torvalds Memory Nodes and assigning tasks to run only within those sets. 2141da177e4SLinus Torvalds This is primarily useful on large SMP or NUMA systems. 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds Say N if unsure. 2171da177e4SLinus Torvalds 218b86ff981SJens Axboeconfig RELAY 219b86ff981SJens Axboe bool "Kernel->user space relay support (formerly relayfs)" 220b86ff981SJens Axboe help 221b86ff981SJens Axboe This option enables support for relay interface support in 222b86ff981SJens Axboe certain file systems (such as debugfs). 223b86ff981SJens Axboe It is designed to provide an efficient mechanism for tools and 224b86ff981SJens Axboe facilities to relay large amounts of data from kernel space to 225b86ff981SJens Axboe user space. 226b86ff981SJens Axboe 227b86ff981SJens Axboe If unsure, say N. 228b86ff981SJens Axboe 229dbec4866SSam Ravnborgsource "usr/Kconfig" 230dbec4866SSam Ravnborg 231e585e470SMatt Mackallconfig UID16 232e585e470SMatt Mackall bool "Enable 16-bit UID system calls" if EMBEDDED 2332308accaSAdrian Bunk depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 234e585e470SMatt Mackall default y 235e585e470SMatt Mackall help 236e585e470SMatt Mackall This enables the legacy 16-bit UID syscall wrappers. 237e585e470SMatt Mackall 23864ca9004SMatt Mackallconfig VM86 23964ca9004SMatt Mackall depends X86 24064ca9004SMatt Mackall default y 24164ca9004SMatt Mackall bool "Enable VM86 support" if EMBEDDED 24264ca9004SMatt Mackall help 24364ca9004SMatt Mackall This option is required by programs like DOSEMU to run 16-bit legacy 24464ca9004SMatt Mackall code on X86 processors. It also may be needed by software like 24564ca9004SMatt Mackall XFree86 to initialize some video cards via BIOS. Disabling this 24664ca9004SMatt Mackall option saves about 6k. 24764ca9004SMatt Mackall 248c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE 249c45b4f1fSLinus Torvalds bool "Optimize for size (Look out for broken compilers!)" 250c45b4f1fSLinus Torvalds default y 251c45b4f1fSLinus Torvalds depends on ARM || H8300 || EXPERIMENTAL 252c45b4f1fSLinus Torvalds help 253c45b4f1fSLinus Torvalds Enabling this option will pass "-Os" instead of "-O2" to gcc 254c45b4f1fSLinus Torvalds resulting in a smaller kernel. 255c45b4f1fSLinus Torvalds 256c45b4f1fSLinus Torvalds WARNING: some versions of gcc may generate incorrect code with this 257c45b4f1fSLinus Torvalds option. If problems are observed, a gcc upgrade may be needed. 258c45b4f1fSLinus Torvalds 259c45b4f1fSLinus Torvalds If unsure, say N. 260c45b4f1fSLinus Torvalds 2611da177e4SLinus Torvaldsmenuconfig EMBEDDED 2621da177e4SLinus Torvalds bool "Configure standard kernel features (for small systems)" 2631da177e4SLinus Torvalds help 2641da177e4SLinus Torvalds This option allows certain base kernel options and settings 2651da177e4SLinus Torvalds to be disabled or tweaked. This is for specialized 2661da177e4SLinus Torvalds environments which can tolerate a "non-standard" kernel. 2671da177e4SLinus Torvalds Only use this if you really know what you are doing. 2681da177e4SLinus Torvalds 2691da177e4SLinus Torvaldsconfig KALLSYMS 2701da177e4SLinus Torvalds bool "Load all symbols for debugging/kksymoops" if EMBEDDED 2711da177e4SLinus Torvalds default y 2721da177e4SLinus Torvalds help 2731da177e4SLinus Torvalds Say Y here to let the kernel print out symbolic crash information and 2741da177e4SLinus Torvalds symbolic stack backtraces. This increases the size of the kernel 2751da177e4SLinus Torvalds somewhat, as all symbols have to be loaded into the kernel image. 2761da177e4SLinus Torvalds 2771da177e4SLinus Torvaldsconfig KALLSYMS_ALL 2781da177e4SLinus Torvalds bool "Include all symbols in kallsyms" 2791da177e4SLinus Torvalds depends on DEBUG_KERNEL && KALLSYMS 2801da177e4SLinus Torvalds help 2811da177e4SLinus Torvalds Normally kallsyms only contains the symbols of functions, for nicer 2821da177e4SLinus Torvalds OOPS messages. Some debuggers can use kallsyms for other 283f9f97bc0SJesper Juhl symbols too: say Y here to include all symbols, if you need them 284f9f97bc0SJesper Juhl and you don't care about adding 300k to the size of your kernel. 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds Say N. 2871da177e4SLinus Torvalds 2881da177e4SLinus Torvaldsconfig KALLSYMS_EXTRA_PASS 2891da177e4SLinus Torvalds bool "Do an extra kallsyms pass" 2901da177e4SLinus Torvalds depends on KALLSYMS 2911da177e4SLinus Torvalds help 2921da177e4SLinus Torvalds If kallsyms is not working correctly, the build will fail with 2931da177e4SLinus Torvalds inconsistent kallsyms data. If that occurs, log a bug report and 2941da177e4SLinus Torvalds turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 2951da177e4SLinus Torvalds Always say N here unless you find a bug in kallsyms, which must be 2961da177e4SLinus Torvalds reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 2971da177e4SLinus Torvalds you wait for kallsyms to be fixed. 2981da177e4SLinus Torvalds 299d59745ceSMatt Mackall 300712f47ceSGreg Kroah-Hartmanconfig HOTPLUG 301712f47ceSGreg Kroah-Hartman bool "Support for hot-pluggable devices" if EMBEDDED 302712f47ceSGreg Kroah-Hartman default y 303712f47ceSGreg Kroah-Hartman help 304712f47ceSGreg Kroah-Hartman This option is provided for the case where no hotplug or uevent 305712f47ceSGreg Kroah-Hartman capabilities is wanted by the kernel. You should only consider 306712f47ceSGreg Kroah-Hartman disabling this option for embedded systems that do not use modules, a 307712f47ceSGreg Kroah-Hartman dynamic /dev tree, or dynamic device discovery. Just say Y. 308712f47ceSGreg Kroah-Hartman 309d59745ceSMatt Mackallconfig PRINTK 310d59745ceSMatt Mackall default y 311d59745ceSMatt Mackall bool "Enable support for printk" if EMBEDDED 312d59745ceSMatt Mackall help 313d59745ceSMatt Mackall This option enables normal printk support. Removing it 314d59745ceSMatt Mackall eliminates most of the message strings from the kernel image 315d59745ceSMatt Mackall and makes the kernel more or less silent. As this makes it 316d59745ceSMatt Mackall very difficult to diagnose system problems, saying N here is 317d59745ceSMatt Mackall strongly discouraged. 318d59745ceSMatt Mackall 319c8538a7aSMatt Mackallconfig BUG 320c8538a7aSMatt Mackall bool "BUG() support" if EMBEDDED 321c8538a7aSMatt Mackall default y 322c8538a7aSMatt Mackall help 323c8538a7aSMatt Mackall Disabling this option eliminates support for BUG and WARN, reducing 324c8538a7aSMatt Mackall the size of your kernel image and potentially quietly ignoring 325c8538a7aSMatt Mackall numerous fatal conditions. You should only consider disabling this 326c8538a7aSMatt Mackall option for embedded systems with no facilities for reporting errors. 327c8538a7aSMatt Mackall Just say Y. 328c8538a7aSMatt Mackall 329708e9a79SMatt Mackallconfig ELF_CORE 330708e9a79SMatt Mackall default y 331708e9a79SMatt Mackall bool "Enable ELF core dumps" if EMBEDDED 332708e9a79SMatt Mackall help 333708e9a79SMatt Mackall Enable support for generating core dumps. Disabling saves about 4k. 334708e9a79SMatt Mackall 3351da177e4SLinus Torvaldsconfig BASE_FULL 3361da177e4SLinus Torvalds default y 3371da177e4SLinus Torvalds bool "Enable full-sized data structures for core" if EMBEDDED 3381da177e4SLinus Torvalds help 3391da177e4SLinus Torvalds Disabling this option reduces the size of miscellaneous core 3401da177e4SLinus Torvalds kernel data structures. This saves memory on small machines, 3411da177e4SLinus Torvalds but may reduce performance. 3421da177e4SLinus Torvalds 3431da177e4SLinus Torvaldsconfig FUTEX 3441da177e4SLinus Torvalds bool "Enable futex support" if EMBEDDED 3451da177e4SLinus Torvalds default y 3461da177e4SLinus Torvalds help 3471da177e4SLinus Torvalds Disabling this option will cause the kernel to be built without 3481da177e4SLinus Torvalds support for "fast userspace mutexes". The resulting kernel may not 3491da177e4SLinus Torvalds run glibc-based applications correctly. 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvaldsconfig EPOLL 3521da177e4SLinus Torvalds bool "Enable eventpoll support" if EMBEDDED 3531da177e4SLinus Torvalds default y 3541da177e4SLinus Torvalds help 3551da177e4SLinus Torvalds Disabling this option will cause the kernel to be built without 3561da177e4SLinus Torvalds support for epoll family of system calls. 3571da177e4SLinus Torvalds 3581da177e4SLinus Torvaldsconfig SHMEM 3591da177e4SLinus Torvalds bool "Use full shmem filesystem" if EMBEDDED 3601da177e4SLinus Torvalds default y 3611da177e4SLinus Torvalds depends on MMU 3621da177e4SLinus Torvalds help 3631da177e4SLinus Torvalds The shmem is an internal filesystem used to manage shared memory. 3641da177e4SLinus Torvalds It is backed by swap and manages resource limits. It is also exported 3651da177e4SLinus Torvalds to userspace as tmpfs if TMPFS is enabled. Disabling this 3661da177e4SLinus Torvalds option replaces shmem and tmpfs with the much simpler ramfs code, 3671da177e4SLinus Torvalds which may be appropriate on small systems without swap. 3681da177e4SLinus Torvalds 36910cef602SMatt Mackallconfig SLAB 37010cef602SMatt Mackall default y 37110cef602SMatt Mackall bool "Use full SLAB allocator" if EMBEDDED 37210cef602SMatt Mackall help 37310cef602SMatt Mackall Disabling this replaces the advanced SLAB allocator and 37410cef602SMatt Mackall kmalloc support with the drastically simpler SLOB allocator. 37510cef602SMatt Mackall SLOB is more space efficient but does not scale well and is 37610cef602SMatt Mackall more susceptible to fragmentation. 37710cef602SMatt Mackall 3781da177e4SLinus Torvaldsendmenu # General setup 3791da177e4SLinus Torvalds 3801da177e4SLinus Torvaldsconfig TINY_SHMEM 3811da177e4SLinus Torvalds default !SHMEM 3821da177e4SLinus Torvalds bool 3831da177e4SLinus Torvalds 3841da177e4SLinus Torvaldsconfig BASE_SMALL 3851da177e4SLinus Torvalds int 3861da177e4SLinus Torvalds default 0 if BASE_FULL 3871da177e4SLinus Torvalds default 1 if !BASE_FULL 3881da177e4SLinus Torvalds 38910cef602SMatt Mackallconfig SLOB 39010cef602SMatt Mackall default !SLAB 39110cef602SMatt Mackall bool 39210cef602SMatt Mackall 393fd279197SAdrian Bunkconfig OBSOLETE_INTERMODULE 394fd279197SAdrian Bunk tristate 395fd279197SAdrian Bunk 3961da177e4SLinus Torvaldsmenu "Loadable module support" 3971da177e4SLinus Torvalds 3981da177e4SLinus Torvaldsconfig MODULES 3991da177e4SLinus Torvalds bool "Enable loadable module support" 4001da177e4SLinus Torvalds help 4011da177e4SLinus Torvalds Kernel modules are small pieces of compiled code which can 4021da177e4SLinus Torvalds be inserted in the running kernel, rather than being 4031da177e4SLinus Torvalds permanently built into the kernel. You use the "modprobe" 4041da177e4SLinus Torvalds tool to add (and sometimes remove) them. If you say Y here, 4051da177e4SLinus Torvalds many parts of the kernel can be built as modules (by 4061da177e4SLinus Torvalds answering M instead of Y where indicated): this is most 4071da177e4SLinus Torvalds useful for infrequently used options which are not required 4081da177e4SLinus Torvalds for booting. For more information, see the man pages for 4091da177e4SLinus Torvalds modprobe, lsmod, modinfo, insmod and rmmod. 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds If you say Y here, you will need to run "make 4121da177e4SLinus Torvalds modules_install" to put the modules under /lib/modules/ 4131da177e4SLinus Torvalds where modprobe can find them (you may need to be root to do 4141da177e4SLinus Torvalds this). 4151da177e4SLinus Torvalds 4161da177e4SLinus Torvalds If unsure, say Y. 4171da177e4SLinus Torvalds 4181da177e4SLinus Torvaldsconfig MODULE_UNLOAD 4191da177e4SLinus Torvalds bool "Module unloading" 4201da177e4SLinus Torvalds depends on MODULES 4211da177e4SLinus Torvalds help 4221da177e4SLinus Torvalds Without this option you will not be able to unload any 4231da177e4SLinus Torvalds modules (note that some modules may not be unloadable 4241da177e4SLinus Torvalds anyway), which makes your kernel slightly smaller and 4251da177e4SLinus Torvalds simpler. If unsure, say Y. 4261da177e4SLinus Torvalds 4271da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD 4281da177e4SLinus Torvalds bool "Forced module unloading" 4291da177e4SLinus Torvalds depends on MODULE_UNLOAD && EXPERIMENTAL 4301da177e4SLinus Torvalds help 4311da177e4SLinus Torvalds This option allows you to force a module to unload, even if the 4321da177e4SLinus Torvalds kernel believes it is unsafe: the kernel will remove the module 4331da177e4SLinus Torvalds without waiting for anyone to stop using it (using the -f option to 4341da177e4SLinus Torvalds rmmod). This is mainly for kernel developers and desperate users. 4351da177e4SLinus Torvalds If unsure, say N. 4361da177e4SLinus Torvalds 4371da177e4SLinus Torvaldsconfig MODVERSIONS 4380d541643SSam Ravnborg bool "Module versioning support" 4390d541643SSam Ravnborg depends on MODULES 4401da177e4SLinus Torvalds help 4411da177e4SLinus Torvalds Usually, you have to use modules compiled with your kernel. 4421da177e4SLinus Torvalds Saying Y here makes it sometimes possible to use modules 4431da177e4SLinus Torvalds compiled for different kernels, by adding enough information 4441da177e4SLinus Torvalds to the modules to (hopefully) spot any changes which would 4451da177e4SLinus Torvalds make them incompatible with the kernel you are running. If 4461da177e4SLinus Torvalds unsure, say N. 4471da177e4SLinus Torvalds 4481da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL 4491da177e4SLinus Torvalds bool "Source checksum for all modules" 4501da177e4SLinus Torvalds depends on MODULES 4511da177e4SLinus Torvalds help 4521da177e4SLinus Torvalds Modules which contain a MODULE_VERSION get an extra "srcversion" 4531da177e4SLinus Torvalds field inserted into their modinfo section, which contains a 4541da177e4SLinus Torvalds sum of the source files which made it. This helps maintainers 4551da177e4SLinus Torvalds see exactly which source was used to build a module (since 4561da177e4SLinus Torvalds others sometimes change the module source without updating 4571da177e4SLinus Torvalds the version). With this option, such a "srcversion" field 4581da177e4SLinus Torvalds will be created for all modules. If unsure, say N. 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvaldsconfig KMOD 4611da177e4SLinus Torvalds bool "Automatic kernel module loading" 4621da177e4SLinus Torvalds depends on MODULES 4631da177e4SLinus Torvalds help 4641da177e4SLinus Torvalds Normally when you have selected some parts of the kernel to 4651da177e4SLinus Torvalds be created as kernel modules, you must load them (using the 4661da177e4SLinus Torvalds "modprobe" command) before you can use them. If you say Y 4671da177e4SLinus Torvalds here, some parts of the kernel will be able to load modules 4681da177e4SLinus Torvalds automatically: when a part of the kernel needs a module, it 4691da177e4SLinus Torvalds runs modprobe with the appropriate arguments, thereby 4701da177e4SLinus Torvalds loading the module if it is available. If unsure, say Y. 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvaldsconfig STOP_MACHINE 4731da177e4SLinus Torvalds bool 4741da177e4SLinus Torvalds default y 4751da177e4SLinus Torvalds depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 4761da177e4SLinus Torvalds help 4771da177e4SLinus Torvalds Need stop_machine() primitive. 4781da177e4SLinus Torvaldsendmenu 4793a65dfe8SJens Axboe 4803a65dfe8SJens Axboemenu "Block layer" 4813a65dfe8SJens Axboesource "block/Kconfig" 4823a65dfe8SJens Axboeendmenu 483