5 default "/lib/modules/$UNAME_RELEASE/.config"
6 default "/etc/kernel-config"
7 default "/boot/config-$UNAME_RELEASE"
8 default "arch/$ARCH/defconfig"
10 menu "Code maturity level options"
13 bool "Prompt for development and/or incomplete code/drivers"
15 Some of the various things that Linux supports (such as network
16 drivers, file systems, network protocols, etc.) can be in a state
17 of development where the functionality, stability, or the level of
18 testing is not yet high enough for general use. This is usually
19 known as the "alpha-test" phase among developers. If a feature is
20 currently in alpha-test, then the developers usually discourage
21 uninformed widespread use of this feature by the general public to
22 avoid "Why doesn't this work?" type mail messages. However, active
23 testing and use of these systems is welcomed. Just be aware that it
24 may not meet the normal level of reliability or it may fail to work
25 in some special cases. Detailed bug reports from people familiar
26 with the kernel internals are usually welcomed by the developers
27 (before submitting bug reports, please read the documents
28 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
29 <file:Documentation/BUG-HUNTING>, and
30 <file:Documentation/oops-tracing.txt> in the kernel source).
32 This option will also make obsoleted drivers available. These are
33 drivers that have been replaced by something else, and/or are
34 scheduled to be removed in a future kernel release.
36 Unless you intend to help test and develop a feature or driver that
37 falls into this category, or you have a situation that requires
38 using these features, you should probably say N here, which will
39 cause the configurator to present you with fewer choices. If
40 you say Y here, you will be offered the choice of using features or
41 drivers that are currently considered to be in the alpha-test phase.
48 depends on BROKEN || !SMP
53 depends on SMP || PREEMPT
56 config INIT_ENV_ARG_LIMIT
61 Maximum of each of the number of arguments and environment
62 variables passed to init from the kernel command line.
69 string "Local version - append to kernel release"
71 Append an extra string to the end of your kernel version.
72 This will show up when you type uname, for example.
73 The string you set here will be appended after the contents of
74 any files with a filename matching localversion* in your
75 object and source tree, in that order. Your total string can
76 be a maximum of 64 characters.
78 config LOCALVERSION_AUTO
79 bool "Automatically append version information to the version string"
82 This will try to automatically determine if the current tree is a
83 release tree by looking for git tags that belong to the current
86 A string of the format -gxxxxxxxx will be added to the localversion
87 if a git-based tree is found. The string generated by this will be
88 appended after any matching localversion* files, and after the value
89 set in CONFIG_LOCALVERSION.
91 (The actual string used here is the first eight characters produced
92 by running the command:
94 $ git rev-parse --verify HEAD
96 which is done within the script "scripts/setlocalversion".)
99 bool "Support for paging of anonymous memory (swap)"
100 depends on MMU && BLOCK
103 This option allows you to choose whether you want to have support
104 for so called swap devices or swap files in your kernel that are
105 used to provide more virtual memory than the actual RAM present
106 in your computer. If unsure say Y.
111 Inter Process Communication is a suite of library functions and
112 system calls which let processes (running programs) synchronize and
113 exchange information. It is generally considered to be a good thing,
114 and some programs won't run unless you say Y here. In particular, if
115 you want to run the DOS emulator dosemu under Linux (read the
116 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
117 you'll need to say Y here.
119 You can find documentation about IPC with "info ipc" and also in
120 section 6.4 of the Linux Programmer's Guide, available from
121 <http://www.tldp.org/guides.html>.
124 bool "IPC Namespaces"
128 Support ipc namespaces. This allows containers, i.e. virtual
129 environments, to use ipc namespaces to provide different ipc
130 objects for different servers. If unsure, say N.
132 config SYSVIPC_SYSCTL
139 bool "POSIX Message Queues"
140 depends on NET && EXPERIMENTAL
142 POSIX variant of message queues is a part of IPC. In POSIX message
143 queues every message has a priority which decides about succession
144 of receiving it by a process. If you want to compile and run
145 programs written e.g. for Solaris with use of its POSIX message
146 queues (functions mq_*) say Y here.
148 POSIX message queues are visible as a filesystem called 'mqueue'
149 and can be mounted somewhere if you want to do filesystem
150 operations on message queues.
154 config BSD_PROCESS_ACCT
155 bool "BSD Process Accounting"
157 If you say Y here, a user level program will be able to instruct the
158 kernel (via a special system call) to write process accounting
159 information to a file: whenever a process exits, information about
160 that process will be appended to the file by the kernel. The
161 information includes things such as creation time, owning user,
162 command name, memory usage, controlling terminal etc. (the complete
163 list is in the struct acct in <file:include/linux/acct.h>). It is
164 up to the user level program to do useful things with this
165 information. This is generally a good idea, so say Y.
167 config BSD_PROCESS_ACCT_V3
168 bool "BSD Process Accounting version 3 file format"
169 depends on BSD_PROCESS_ACCT
172 If you say Y here, the process accounting information is written
173 in a new file format that also logs the process IDs of each
174 process and it's parent. Note that this file format is incompatible
175 with previous v0/v1/v2 file formats, so you will need updated tools
176 for processing it. A preliminary version of these tools is available
177 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
180 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
184 Export selected statistics for tasks/processes through the
185 generic netlink interface. Unlike BSD process accounting, the
186 statistics are available during the lifetime of tasks/processes as
187 responses to commands. Like BSD accounting, they are sent to user
192 config TASK_DELAY_ACCT
193 bool "Enable per-task delay accounting (EXPERIMENTAL)"
196 Collect information on time spent by a task waiting for system
197 resources like cpu, synchronous block I/O completion and swapping
198 in pages. Such statistics can help in setting a task's priorities
199 relative to other tasks for cpu, io, rss limits etc.
204 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
207 Collect extended task accounting data and send the data
208 to userland for processing over the taskstats interface.
212 config TASK_IO_ACCOUNTING
213 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
214 depends on TASK_XACCT
216 Collect information on the number of bytes of storage I/O which this
222 bool "UTS Namespaces"
225 Support uts namespaces. This allows containers, i.e.
226 vservers, to use uts namespaces to provide different
227 uts info for different servers. If unsure, say N.
230 bool "Auditing support"
233 Enable auditing infrastructure that can be used with another
234 kernel subsystem, such as SELinux (which requires this for
235 logging of avc messages output). Does not do system-call
236 auditing without CONFIG_AUDITSYSCALL.
239 bool "Enable system-call auditing support"
240 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
241 default y if SECURITY_SELINUX
243 Enable low-overhead system-call auditing infrastructure that
244 can be used independently or with another kernel subsystem,
245 such as SELinux. To use audit's filesystem watch feature, please
246 ensure that INOTIFY is configured.
249 tristate "Kernel .config support"
251 This option enables the complete Linux kernel ".config" file
252 contents to be saved in the kernel. It provides documentation
253 of which kernel options are used in a running kernel or in an
254 on-disk kernel. This information can be extracted from the kernel
255 image file with the script scripts/extract-ikconfig and used as
256 input to rebuild the current kernel or to build another kernel.
257 It can also be extracted from a running kernel by reading
258 /proc/config.gz if enabled (below).
261 bool "Enable access to .config through /proc/config.gz"
262 depends on IKCONFIG && PROC_FS
264 This option enables access to the kernel configuration file
265 through /proc/config.gz.
268 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
270 default 17 if S390 || LOCKDEP
271 default 16 if X86_NUMAQ || IA64
275 Select kernel log buffer size as a power of 2.
276 Defaults and Examples:
277 17 => 128 KB for S/390
278 16 => 64 KB for x86 NUMAQ or IA-64
280 14 => 16 KB for uniprocessor
285 bool "Cpuset support"
288 This option will let you create and manage CPUSETs which
289 allow dynamically partitioning a system into sets of CPUs and
290 Memory Nodes and assigning tasks to run only within those sets.
291 This is primarily useful on large SMP or NUMA systems.
295 config SYSFS_DEPRECATED
296 bool "Create deprecated sysfs files"
299 This option creates deprecated symlinks such as the
300 "device"-link, the <subsystem>:<name>-link, and the
301 "bus"-link. It may also add deprecated key in the
303 None of these features or values should be used today, as
304 they export driver core implementation details to userspace
305 or export properties which can't be kept stable across kernel
308 If enabled, this option will also move any device structures
309 that belong to a class, back into the /sys/class hierarchy, in
310 order to support older versions of udev.
312 If you are using a distro that was released in 2006 or later,
313 it should be safe to say N here.
316 bool "Kernel->user space relay support (formerly relayfs)"
318 This option enables support for relay interface support in
319 certain file systems (such as debugfs).
320 It is designed to provide an efficient mechanism for tools and
321 facilities to relay large amounts of data from kernel space to
326 config BLK_DEV_INITRD
327 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
328 depends on BROKEN || !FRV
330 The initial RAM filesystem is a ramfs which is loaded by the
331 boot loader (loadlin or lilo) and that is mounted as root
332 before the normal boot procedure. It is typically used to
333 load modules needed to mount the "real" root file system,
334 etc. See <file:Documentation/initrd.txt> for details.
336 If RAM disk support (BLK_DEV_RAM) is also included, this
337 also enables initial RAM disk (initrd) support and adds
338 15 Kbytes (more on some other architectures) to the kernel size.
348 config CC_OPTIMIZE_FOR_SIZE
349 bool "Optimize for size (Look out for broken compilers!)"
351 depends on ARM || H8300 || EXPERIMENTAL
353 Enabling this option will pass "-Os" instead of "-O2" to gcc
354 resulting in a smaller kernel.
356 WARNING: some versions of gcc may generate incorrect code with this
357 option. If problems are observed, a gcc upgrade may be needed.
365 bool "Configure standard kernel features (for small systems)"
367 This option allows certain base kernel options and settings
368 to be disabled or tweaked. This is for specialized
369 environments which can tolerate a "non-standard" kernel.
370 Only use this if you really know what you are doing.
373 bool "Enable 16-bit UID system calls" if EMBEDDED
374 depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
377 This enables the legacy 16-bit UID syscall wrappers.
379 config SYSCTL_SYSCALL
380 bool "Sysctl syscall support" if EMBEDDED
384 sys_sysctl uses binary paths that have been found challenging
385 to properly maintain and use. The interface in /proc/sys
386 using paths with ascii names is now the primary path to this
389 Almost nothing using the binary sysctl interface so if you are
390 trying to save some space it is probably safe to disable this,
391 making your kernel marginally smaller.
393 If unsure say Y here.
396 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
399 Say Y here to let the kernel print out symbolic crash information and
400 symbolic stack backtraces. This increases the size of the kernel
401 somewhat, as all symbols have to be loaded into the kernel image.
404 bool "Include all symbols in kallsyms"
405 depends on DEBUG_KERNEL && KALLSYMS
407 Normally kallsyms only contains the symbols of functions, for nicer
408 OOPS messages. Some debuggers can use kallsyms for other
409 symbols too: say Y here to include all symbols, if you need them
410 and you don't care about adding 300k to the size of your kernel.
414 config KALLSYMS_EXTRA_PASS
415 bool "Do an extra kallsyms pass"
418 If kallsyms is not working correctly, the build will fail with
419 inconsistent kallsyms data. If that occurs, log a bug report and
420 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
421 Always say N here unless you find a bug in kallsyms, which must be
422 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
423 you wait for kallsyms to be fixed.
427 bool "Support for hot-pluggable devices" if EMBEDDED
430 This option is provided for the case where no hotplug or uevent
431 capabilities is wanted by the kernel. You should only consider
432 disabling this option for embedded systems that do not use modules, a
433 dynamic /dev tree, or dynamic device discovery. Just say Y.
437 bool "Enable support for printk" if EMBEDDED
439 This option enables normal printk support. Removing it
440 eliminates most of the message strings from the kernel image
441 and makes the kernel more or less silent. As this makes it
442 very difficult to diagnose system problems, saying N here is
443 strongly discouraged.
446 bool "BUG() support" if EMBEDDED
449 Disabling this option eliminates support for BUG and WARN, reducing
450 the size of your kernel image and potentially quietly ignoring
451 numerous fatal conditions. You should only consider disabling this
452 option for embedded systems with no facilities for reporting errors.
457 bool "Enable ELF core dumps" if EMBEDDED
459 Enable support for generating core dumps. Disabling saves about 4k.
463 bool "Enable full-sized data structures for core" if EMBEDDED
465 Disabling this option reduces the size of miscellaneous core
466 kernel data structures. This saves memory on small machines,
467 but may reduce performance.
470 bool "Enable futex support" if EMBEDDED
474 Disabling this option will cause the kernel to be built without
475 support for "fast userspace mutexes". The resulting kernel may not
476 run glibc-based applications correctly.
479 bool "Enable anonymous inode source" if EMBEDDED
482 Anonymous inode source for pseudo-files like epoll, signalfd,
488 bool "Enable eventpoll support" if EMBEDDED
490 depends on ANON_INODES
492 Disabling this option will cause the kernel to be built without
493 support for epoll family of system calls.
496 bool "Enable signalfd() system call" if EMBEDDED
497 depends on ANON_INODES
500 Enable the signalfd() system call that allows to receive signals
501 on a file descriptor.
506 bool "Enable timerfd() system call" if EMBEDDED
507 depends on ANON_INODES
510 Enable the timerfd() system call that allows to receive timer
511 events on a file descriptor.
516 bool "Enable eventfd() system call" if EMBEDDED
517 depends on ANON_INODES
520 Enable the eventfd() system call that allows to receive both
521 kernel notification (ie. KAIO) or userspace notifications.
526 bool "Use full shmem filesystem" if EMBEDDED
530 The shmem is an internal filesystem used to manage shared memory.
531 It is backed by swap and manages resource limits. It is also exported
532 to userspace as tmpfs if TMPFS is enabled. Disabling this
533 option replaces shmem and tmpfs with the much simpler ramfs code,
534 which may be appropriate on small systems without swap.
536 config VM_EVENT_COUNTERS
538 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
540 VM event counters are needed for event counts to be shown.
541 This option allows the disabling of the VM event counters
542 on EMBEDDED systems. /proc/vmstat will only show page counts
543 if VM event counters are disabled.
547 bool "Enable SLUB debugging support" if EMBEDDED
550 SLUB has extensive debug support features. Disabling these can
551 result in significant savings in code size. This also disables
552 SLUB sysfs support. /sys/slab will not exist and there will be
553 no support for cache validation etc.
556 prompt "Choose SLAB allocator"
559 This option allows to select a slab allocator.
564 The regular slab allocator that is established and known to work
565 well in all environments. It organizes cache hot objects in
566 per cpu and per node queues. SLAB is the default choice for
570 depends on EXPERIMENTAL && !ARCH_USES_SLAB_PAGE_STRUCT
571 bool "SLUB (Unqueued Allocator)"
573 SLUB is a slab allocator that minimizes cache line usage
574 instead of managing queues of cached objects (SLAB approach).
575 Per cpu caching is realized using slabs of objects instead
576 of queues of objects. SLUB can use memory efficiently
577 and has enhanced diagnostics.
581 # SLOB does not support SMP because SLAB_DESTROY_BY_RCU is unsupported
583 depends on EMBEDDED && !SMP && !SPARSEMEM
584 bool "SLOB (Simple Allocator)"
586 SLOB replaces the SLAB allocator with a drastically simpler
587 allocator. SLOB is more space efficient that SLAB but does not
588 scale well (single lock for all operations) and is also highly
589 susceptible to fragmentation. SLUB can accomplish a higher object
590 density. It is usually better to use SLUB instead of SLOB.
594 endmenu # General setup
606 default 0 if BASE_FULL
607 default 1 if !BASE_FULL
609 menu "Loadable module support"
612 bool "Enable loadable module support"
614 Kernel modules are small pieces of compiled code which can
615 be inserted in the running kernel, rather than being
616 permanently built into the kernel. You use the "modprobe"
617 tool to add (and sometimes remove) them. If you say Y here,
618 many parts of the kernel can be built as modules (by
619 answering M instead of Y where indicated): this is most
620 useful for infrequently used options which are not required
621 for booting. For more information, see the man pages for
622 modprobe, lsmod, modinfo, insmod and rmmod.
624 If you say Y here, you will need to run "make
625 modules_install" to put the modules under /lib/modules/
626 where modprobe can find them (you may need to be root to do
632 bool "Module unloading"
635 Without this option you will not be able to unload any
636 modules (note that some modules may not be unloadable
637 anyway), which makes your kernel slightly smaller and
638 simpler. If unsure, say Y.
640 config MODULE_FORCE_UNLOAD
641 bool "Forced module unloading"
642 depends on MODULE_UNLOAD && EXPERIMENTAL
644 This option allows you to force a module to unload, even if the
645 kernel believes it is unsafe: the kernel will remove the module
646 without waiting for anyone to stop using it (using the -f option to
647 rmmod). This is mainly for kernel developers and desperate users.
651 bool "Module versioning support"
654 Usually, you have to use modules compiled with your kernel.
655 Saying Y here makes it sometimes possible to use modules
656 compiled for different kernels, by adding enough information
657 to the modules to (hopefully) spot any changes which would
658 make them incompatible with the kernel you are running. If
661 config MODULE_SRCVERSION_ALL
662 bool "Source checksum for all modules"
665 Modules which contain a MODULE_VERSION get an extra "srcversion"
666 field inserted into their modinfo section, which contains a
667 sum of the source files which made it. This helps maintainers
668 see exactly which source was used to build a module (since
669 others sometimes change the module source without updating
670 the version). With this option, such a "srcversion" field
671 will be created for all modules. If unsure, say N.
674 bool "Automatic kernel module loading"
677 Normally when you have selected some parts of the kernel to
678 be created as kernel modules, you must load them (using the
679 "modprobe" command) before you can use them. If you say Y
680 here, some parts of the kernel will be able to load modules
681 automatically: when a part of the kernel needs a module, it
682 runs modprobe with the appropriate arguments, thereby
683 loading the module if it is available. If unsure, say Y.
688 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
690 Need stop_machine() primitive.
694 source "block/Kconfig"
projects / linux-2.6 / blob