5 default "/lib/modules/$UNAME_RELEASE/.config"
6 default "/etc/kernel-config"
7 default "/boot/config-$UNAME_RELEASE"
8 default "arch/$ARCH/defconfig"
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33 drivers that have been replaced by something else, and/or are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.
66 string "Local version - append to kernel release"
68 Append an extra string to the end of your kernel version.
69 This will show up when you type uname, for example.
70 The string you set here will be appended after the contents of
71 any files with a filename matching localversion* in your
72 object and source tree, in that order. Your total string can
73 be a maximum of 64 characters.
75 config LOCALVERSION_AUTO
76 bool "Automatically append version information to the version string"
79 This will try to automatically determine if the current tree is a
80 release tree by looking for git tags that belong to the current
83 A string of the format -gxxxxxxxx will be added to the localversion
84 if a git-based tree is found. The string generated by this will be
85 appended after any matching localversion* files, and after the value
86 set in CONFIG_LOCALVERSION.
88 (The actual string used here is the first eight characters produced
89 by running the command:
91 $ git rev-parse --verify HEAD
93 which is done within the script "scripts/setlocalversion".)
96 bool "Support for paging of anonymous memory (swap)"
97 depends on MMU && BLOCK
100 This option allows you to choose whether you want to have support
101 for so called swap devices or swap files in your kernel that are
102 used to provide more virtual memory than the actual RAM present
103 in your computer. If unsure say Y.
108 Inter Process Communication is a suite of library functions and
109 system calls which let processes (running programs) synchronize and
110 exchange information. It is generally considered to be a good thing,
111 and some programs won't run unless you say Y here. In particular, if
112 you want to run the DOS emulator dosemu under Linux (read the
113 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
114 you'll need to say Y here.
116 You can find documentation about IPC with "info ipc" and also in
117 section 6.4 of the Linux Programmer's Guide, available from
118 <http://www.tldp.org/guides.html>.
120 config SYSVIPC_SYSCTL
127 bool "POSIX Message Queues"
128 depends on NET && EXPERIMENTAL
130 POSIX variant of message queues is a part of IPC. In POSIX message
131 queues every message has a priority which decides about succession
132 of receiving it by a process. If you want to compile and run
133 programs written e.g. for Solaris with use of its POSIX message
134 queues (functions mq_*) say Y here.
136 POSIX message queues are visible as a filesystem called 'mqueue'
137 and can be mounted somewhere if you want to do filesystem
138 operations on message queues.
142 config BSD_PROCESS_ACCT
143 bool "BSD Process Accounting"
145 If you say Y here, a user level program will be able to instruct the
146 kernel (via a special system call) to write process accounting
147 information to a file: whenever a process exits, information about
148 that process will be appended to the file by the kernel. The
149 information includes things such as creation time, owning user,
150 command name, memory usage, controlling terminal etc. (the complete
151 list is in the struct acct in <file:include/linux/acct.h>). It is
152 up to the user level program to do useful things with this
153 information. This is generally a good idea, so say Y.
155 config BSD_PROCESS_ACCT_V3
156 bool "BSD Process Accounting version 3 file format"
157 depends on BSD_PROCESS_ACCT
160 If you say Y here, the process accounting information is written
161 in a new file format that also logs the process IDs of each
162 process and it's parent. Note that this file format is incompatible
163 with previous v0/v1/v2 file formats, so you will need updated tools
164 for processing it. A preliminary version of these tools is available
165 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
168 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
172 Export selected statistics for tasks/processes through the
173 generic netlink interface. Unlike BSD process accounting, the
174 statistics are available during the lifetime of tasks/processes as
175 responses to commands. Like BSD accounting, they are sent to user
180 config TASK_DELAY_ACCT
181 bool "Enable per-task delay accounting (EXPERIMENTAL)"
184 Collect information on time spent by a task waiting for system
185 resources like cpu, synchronous block I/O completion and swapping
186 in pages. Such statistics can help in setting a task's priorities
187 relative to other tasks for cpu, io, rss limits etc.
192 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
195 Collect extended task accounting data and send the data
196 to userland for processing over the taskstats interface.
200 config TASK_IO_ACCOUNTING
201 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
202 depends on TASK_XACCT
204 Collect information on the number of bytes of storage I/O which this
210 bool "User Namespaces (EXPERIMENTAL)"
212 depends on EXPERIMENTAL
214 Support user namespaces. This allows containers, i.e.
215 vservers, to use user namespaces to provide different
216 user info for different servers. If unsure, say N.
219 bool "Auditing support"
222 Enable auditing infrastructure that can be used with another
223 kernel subsystem, such as SELinux (which requires this for
224 logging of avc messages output). Does not do system-call
225 auditing without CONFIG_AUDITSYSCALL.
228 bool "Enable system-call auditing support"
229 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
230 default y if SECURITY_SELINUX
232 Enable low-overhead system-call auditing infrastructure that
233 can be used independently or with another kernel subsystem,
234 such as SELinux. To use audit's filesystem watch feature, please
235 ensure that INOTIFY is configured.
238 tristate "Kernel .config support"
240 This option enables the complete Linux kernel ".config" file
241 contents to be saved in the kernel. It provides documentation
242 of which kernel options are used in a running kernel or in an
243 on-disk kernel. This information can be extracted from the kernel
244 image file with the script scripts/extract-ikconfig and used as
245 input to rebuild the current kernel or to build another kernel.
246 It can also be extracted from a running kernel by reading
247 /proc/config.gz if enabled (below).
250 bool "Enable access to .config through /proc/config.gz"
251 depends on IKCONFIG && PROC_FS
253 This option enables access to the kernel configuration file
254 through /proc/config.gz.
257 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
259 default 17 if S390 || LOCKDEP
260 default 16 if X86_NUMAQ || IA64
264 Select kernel log buffer size as a power of 2.
265 Defaults and Examples:
266 17 => 128 KB for S/390
267 16 => 64 KB for x86 NUMAQ or IA-64
269 14 => 16 KB for uniprocessor
274 bool "Cpuset support"
277 This option will let you create and manage CPUSETs which
278 allow dynamically partitioning a system into sets of CPUs and
279 Memory Nodes and assigning tasks to run only within those sets.
280 This is primarily useful on large SMP or NUMA systems.
284 config FAIR_GROUP_SCHED
285 bool "Fair group cpu scheduler"
287 depends on EXPERIMENTAL
289 This feature lets cpu scheduler recognize task groups and control cpu
290 bandwidth allocation to such task groups.
292 config SYSFS_DEPRECATED
293 bool "Create deprecated sysfs files"
296 This option creates deprecated symlinks such as the
297 "device"-link, the <subsystem>:<name>-link, and the
298 "bus"-link. It may also add deprecated key in the
300 None of these features or values should be used today, as
301 they export driver core implementation details to userspace
302 or export properties which can't be kept stable across kernel
305 If enabled, this option will also move any device structures
306 that belong to a class, back into the /sys/class hierarchy, in
307 order to support older versions of udev.
309 If you are using a distro that was released in 2006 or later,
310 it should be safe to say N here.
313 bool "Kernel->user space relay support (formerly relayfs)"
315 This option enables support for relay interface support in
316 certain file systems (such as debugfs).
317 It is designed to provide an efficient mechanism for tools and
318 facilities to relay large amounts of data from kernel space to
323 config BLK_DEV_INITRD
324 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
325 depends on BROKEN || !FRV
327 The initial RAM filesystem is a ramfs which is loaded by the
328 boot loader (loadlin or lilo) and that is mounted as root
329 before the normal boot procedure. It is typically used to
330 load modules needed to mount the "real" root file system,
331 etc. See <file:Documentation/initrd.txt> for details.
333 If RAM disk support (BLK_DEV_RAM) is also included, this
334 also enables initial RAM disk (initrd) support and adds
335 15 Kbytes (more on some other architectures) to the kernel size.
345 config CC_OPTIMIZE_FOR_SIZE
346 bool "Optimize for size (Look out for broken compilers!)"
348 depends on ARM || H8300 || SUPERH || EXPERIMENTAL
350 Enabling this option will pass "-Os" instead of "-O2" to gcc
351 resulting in a smaller kernel.
353 WARNING: some versions of gcc may generate incorrect code with this
354 option. If problems are observed, a gcc upgrade may be needed.
362 bool "Configure standard kernel features (for small systems)"
364 This option allows certain base kernel options and settings
365 to be disabled or tweaked. This is for specialized
366 environments which can tolerate a "non-standard" kernel.
367 Only use this if you really know what you are doing.
370 bool "Enable 16-bit UID system calls" if EMBEDDED
371 depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
374 This enables the legacy 16-bit UID syscall wrappers.
376 config SYSCTL_SYSCALL
377 bool "Sysctl syscall support" if EMBEDDED
381 sys_sysctl uses binary paths that have been found challenging
382 to properly maintain and use. The interface in /proc/sys
383 using paths with ascii names is now the primary path to this
386 Almost nothing using the binary sysctl interface so if you are
387 trying to save some space it is probably safe to disable this,
388 making your kernel marginally smaller.
390 If unsure say Y here.
393 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
396 Say Y here to let the kernel print out symbolic crash information and
397 symbolic stack backtraces. This increases the size of the kernel
398 somewhat, as all symbols have to be loaded into the kernel image.
401 bool "Include all symbols in kallsyms"
402 depends on DEBUG_KERNEL && KALLSYMS
404 Normally kallsyms only contains the symbols of functions, for nicer
405 OOPS messages. Some debuggers can use kallsyms for other
406 symbols too: say Y here to include all symbols, if you need them
407 and you don't care about adding 300k to the size of your kernel.
411 config KALLSYMS_EXTRA_PASS
412 bool "Do an extra kallsyms pass"
415 If kallsyms is not working correctly, the build will fail with
416 inconsistent kallsyms data. If that occurs, log a bug report and
417 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
418 Always say N here unless you find a bug in kallsyms, which must be
419 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
420 you wait for kallsyms to be fixed.
424 bool "Support for hot-pluggable devices" if EMBEDDED
427 This option is provided for the case where no hotplug or uevent
428 capabilities is wanted by the kernel. You should only consider
429 disabling this option for embedded systems that do not use modules, a
430 dynamic /dev tree, or dynamic device discovery. Just say Y.
434 bool "Enable support for printk" if EMBEDDED
436 This option enables normal printk support. Removing it
437 eliminates most of the message strings from the kernel image
438 and makes the kernel more or less silent. As this makes it
439 very difficult to diagnose system problems, saying N here is
440 strongly discouraged.
443 bool "BUG() support" if EMBEDDED
446 Disabling this option eliminates support for BUG and WARN, reducing
447 the size of your kernel image and potentially quietly ignoring
448 numerous fatal conditions. You should only consider disabling this
449 option for embedded systems with no facilities for reporting errors.
454 bool "Enable ELF core dumps" if EMBEDDED
456 Enable support for generating core dumps. Disabling saves about 4k.
460 bool "Enable full-sized data structures for core" if EMBEDDED
462 Disabling this option reduces the size of miscellaneous core
463 kernel data structures. This saves memory on small machines,
464 but may reduce performance.
467 bool "Enable futex support" if EMBEDDED
471 Disabling this option will cause the kernel to be built without
472 support for "fast userspace mutexes". The resulting kernel may not
473 run glibc-based applications correctly.
479 bool "Enable eventpoll support" if EMBEDDED
483 Disabling this option will cause the kernel to be built without
484 support for epoll family of system calls.
487 bool "Enable signalfd() system call" if EMBEDDED
491 Enable the signalfd() system call that allows to receive signals
492 on a file descriptor.
497 bool "Enable timerfd() system call" if EMBEDDED
502 Enable the timerfd() system call that allows to receive timer
503 events on a file descriptor.
508 bool "Enable eventfd() system call" if EMBEDDED
512 Enable the eventfd() system call that allows to receive both
513 kernel notification (ie. KAIO) or userspace notifications.
518 bool "Use full shmem filesystem" if EMBEDDED
522 The shmem is an internal filesystem used to manage shared memory.
523 It is backed by swap and manages resource limits. It is also exported
524 to userspace as tmpfs if TMPFS is enabled. Disabling this
525 option replaces shmem and tmpfs with the much simpler ramfs code,
526 which may be appropriate on small systems without swap.
528 config VM_EVENT_COUNTERS
530 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
532 VM event counters are needed for event counts to be shown.
533 This option allows the disabling of the VM event counters
534 on EMBEDDED systems. /proc/vmstat will only show page counts
535 if VM event counters are disabled.
539 bool "Enable SLUB debugging support" if EMBEDDED
542 SLUB has extensive debug support features. Disabling these can
543 result in significant savings in code size. This also disables
544 SLUB sysfs support. /sys/slab will not exist and there will be
545 no support for cache validation etc.
548 prompt "Choose SLAB allocator"
551 This option allows to select a slab allocator.
556 The regular slab allocator that is established and known to work
557 well in all environments. It organizes cache hot objects in
558 per cpu and per node queues. SLAB is the default choice for
562 bool "SLUB (Unqueued Allocator)"
564 SLUB is a slab allocator that minimizes cache line usage
565 instead of managing queues of cached objects (SLAB approach).
566 Per cpu caching is realized using slabs of objects instead
567 of queues of objects. SLUB can use memory efficiently
568 and has enhanced diagnostics.
572 bool "SLOB (Simple Allocator)"
574 SLOB replaces the SLAB allocator with a drastically simpler
575 allocator. SLOB is more space efficient than SLAB but does not
576 scale well (single lock for all operations) and is also highly
577 susceptible to fragmentation. SLUB can accomplish a higher object
578 density. It is usually better to use SLUB instead of SLOB.
582 endmenu # General setup
594 default 0 if BASE_FULL
595 default 1 if !BASE_FULL
598 bool "Enable loadable module support"
600 Kernel modules are small pieces of compiled code which can
601 be inserted in the running kernel, rather than being
602 permanently built into the kernel. You use the "modprobe"
603 tool to add (and sometimes remove) them. If you say Y here,
604 many parts of the kernel can be built as modules (by
605 answering M instead of Y where indicated): this is most
606 useful for infrequently used options which are not required
607 for booting. For more information, see the man pages for
608 modprobe, lsmod, modinfo, insmod and rmmod.
610 If you say Y here, you will need to run "make
611 modules_install" to put the modules under /lib/modules/
612 where modprobe can find them (you may need to be root to do
618 bool "Module unloading"
621 Without this option you will not be able to unload any
622 modules (note that some modules may not be unloadable
623 anyway), which makes your kernel slightly smaller and
624 simpler. If unsure, say Y.
626 config MODULE_FORCE_UNLOAD
627 bool "Forced module unloading"
628 depends on MODULE_UNLOAD && EXPERIMENTAL
630 This option allows you to force a module to unload, even if the
631 kernel believes it is unsafe: the kernel will remove the module
632 without waiting for anyone to stop using it (using the -f option to
633 rmmod). This is mainly for kernel developers and desperate users.
637 bool "Module versioning support"
640 Usually, you have to use modules compiled with your kernel.
641 Saying Y here makes it sometimes possible to use modules
642 compiled for different kernels, by adding enough information
643 to the modules to (hopefully) spot any changes which would
644 make them incompatible with the kernel you are running. If
647 config MODULE_SRCVERSION_ALL
648 bool "Source checksum for all modules"
651 Modules which contain a MODULE_VERSION get an extra "srcversion"
652 field inserted into their modinfo section, which contains a
653 sum of the source files which made it. This helps maintainers
654 see exactly which source was used to build a module (since
655 others sometimes change the module source without updating
656 the version). With this option, such a "srcversion" field
657 will be created for all modules. If unsure, say N.
660 bool "Automatic kernel module loading"
663 Normally when you have selected some parts of the kernel to
664 be created as kernel modules, you must load them (using the
665 "modprobe" command) before you can use them. If you say Y
666 here, some parts of the kernel will be able to load modules
667 automatically: when a part of the kernel needs a module, it
668 runs modprobe with the appropriate arguments, thereby
669 loading the module if it is available. If unsure, say Y.
674 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
676 Need stop_machine() primitive.
678 source "block/Kconfig"
projects / linux-2.6 / blob