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33 drivers that have been replaced by something else, and/or are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. To use this feature you will
147 also need mqueue library, available from
148 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
150 POSIX message queues are visible as a filesystem called 'mqueue'
151 and can be mounted somewhere if you want to do filesystem
152 operations on message queues.
156 config BSD_PROCESS_ACCT
157 bool "BSD Process Accounting"
159 If you say Y here, a user level program will be able to instruct the
160 kernel (via a special system call) to write process accounting
161 information to a file: whenever a process exits, information about
162 that process will be appended to the file by the kernel. The
163 information includes things such as creation time, owning user,
164 command name, memory usage, controlling terminal etc. (the complete
165 list is in the struct acct in <file:include/linux/acct.h>). It is
166 up to the user level program to do useful things with this
167 information. This is generally a good idea, so say Y.
169 config BSD_PROCESS_ACCT_V3
170 bool "BSD Process Accounting version 3 file format"
171 depends on BSD_PROCESS_ACCT
174 If you say Y here, the process accounting information is written
175 in a new file format that also logs the process IDs of each
176 process and it's parent. Note that this file format is incompatible
177 with previous v0/v1/v2 file formats, so you will need updated tools
178 for processing it. A preliminary version of these tools is available
179 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
182 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
186 Export selected statistics for tasks/processes through the
187 generic netlink interface. Unlike BSD process accounting, the
188 statistics are available during the lifetime of tasks/processes as
189 responses to commands. Like BSD accounting, they are sent to user
194 config TASK_DELAY_ACCT
195 bool "Enable per-task delay accounting (EXPERIMENTAL)"
198 Collect information on time spent by a task waiting for system
199 resources like cpu, synchronous block I/O completion and swapping
200 in pages. Such statistics can help in setting a task's priorities
201 relative to other tasks for cpu, io, rss limits etc.
206 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
209 Collect extended task accounting data and send the data
210 to userland for processing over the taskstats interface.
214 config TASK_IO_ACCOUNTING
215 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
216 depends on TASK_XACCT
218 Collect information on the number of bytes of storage I/O which this
224 bool "UTS Namespaces"
227 Support uts namespaces. This allows containers, i.e.
228 vservers, to use uts namespaces to provide different
229 uts info for different servers. If unsure, say N.
232 bool "Auditing support"
235 Enable auditing infrastructure that can be used with another
236 kernel subsystem, such as SELinux (which requires this for
237 logging of avc messages output). Does not do system-call
238 auditing without CONFIG_AUDITSYSCALL.
241 bool "Enable system-call auditing support"
242 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
243 default y if SECURITY_SELINUX
245 Enable low-overhead system-call auditing infrastructure that
246 can be used independently or with another kernel subsystem,
247 such as SELinux. To use audit's filesystem watch feature, please
248 ensure that INOTIFY is configured.
251 tristate "Kernel .config support"
253 This option enables the complete Linux kernel ".config" file
254 contents to be saved in the kernel. It provides documentation
255 of which kernel options are used in a running kernel or in an
256 on-disk kernel. This information can be extracted from the kernel
257 image file with the script scripts/extract-ikconfig and used as
258 input to rebuild the current kernel or to build another kernel.
259 It can also be extracted from a running kernel by reading
260 /proc/config.gz if enabled (below).
263 bool "Enable access to .config through /proc/config.gz"
264 depends on IKCONFIG && PROC_FS
266 This option enables access to the kernel configuration file
267 through /proc/config.gz.
270 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
272 default 17 if S390 || LOCKDEP
273 default 16 if X86_NUMAQ || IA64
277 Select kernel log buffer size as a power of 2.
278 Defaults and Examples:
279 17 => 128 KB for S/390
280 16 => 64 KB for x86 NUMAQ or IA-64
282 14 => 16 KB for uniprocessor
287 bool "Cpuset support"
290 This option will let you create and manage CPUSETs which
291 allow dynamically partitioning a system into sets of CPUs and
292 Memory Nodes and assigning tasks to run only within those sets.
293 This is primarily useful on large SMP or NUMA systems.
297 config SYSFS_DEPRECATED
298 bool "Create deprecated sysfs files"
301 This option creates deprecated symlinks such as the
302 "device"-link, the <subsystem>:<name>-link, and the
303 "bus"-link. It may also add deprecated key in the
305 None of these features or values should be used today, as
306 they export driver core implementation details to userspace
307 or export properties which can't be kept stable across kernel
310 If enabled, this option will also move any device structures
311 that belong to a class, back into the /sys/class heirachy, in
312 order to support older versions of udev.
314 If you are using a distro that was released in 2006 or later,
315 it should be safe to say N here.
318 bool "Kernel->user space relay support (formerly relayfs)"
320 This option enables support for relay interface support in
321 certain file systems (such as debugfs).
322 It is designed to provide an efficient mechanism for tools and
323 facilities to relay large amounts of data from kernel space to
328 config BLK_DEV_INITRD
329 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
330 depends on BROKEN || !FRV
332 The initial RAM filesystem is a ramfs which is loaded by the
333 boot loader (loadlin or lilo) and that is mounted as root
334 before the normal boot procedure. It is typically used to
335 load modules needed to mount the "real" root file system,
336 etc. See <file:Documentation/initrd.txt> for details.
338 If RAM disk support (BLK_DEV_RAM) is also included, this
339 also enables initial RAM disk (initrd) support and adds
340 15 Kbytes (more on some other architectures) to the kernel size.
350 config CC_OPTIMIZE_FOR_SIZE
351 bool "Optimize for size (Look out for broken compilers!)"
353 depends on ARM || H8300 || EXPERIMENTAL
355 Enabling this option will pass "-Os" instead of "-O2" to gcc
356 resulting in a smaller kernel.
358 WARNING: some versions of gcc may generate incorrect code with this
359 option. If problems are observed, a gcc upgrade may be needed.
367 bool "Configure standard kernel features (for small systems)"
369 This option allows certain base kernel options and settings
370 to be disabled or tweaked. This is for specialized
371 environments which can tolerate a "non-standard" kernel.
372 Only use this if you really know what you are doing.
375 bool "Enable 16-bit UID system calls" if EMBEDDED
376 depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
379 This enables the legacy 16-bit UID syscall wrappers.
381 config SYSCTL_SYSCALL
382 bool "Sysctl syscall support" if EMBEDDED
386 sys_sysctl uses binary paths that have been found challenging
387 to properly maintain and use. The interface in /proc/sys
388 using paths with ascii names is now the primary path to this
391 Almost nothing using the binary sysctl interface so if you are
392 trying to save some space it is probably safe to disable this,
393 making your kernel marginally smaller.
395 If unsure say Y here.
398 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
401 Say Y here to let the kernel print out symbolic crash information and
402 symbolic stack backtraces. This increases the size of the kernel
403 somewhat, as all symbols have to be loaded into the kernel image.
406 bool "Include all symbols in kallsyms"
407 depends on DEBUG_KERNEL && KALLSYMS
409 Normally kallsyms only contains the symbols of functions, for nicer
410 OOPS messages. Some debuggers can use kallsyms for other
411 symbols too: say Y here to include all symbols, if you need them
412 and you don't care about adding 300k to the size of your kernel.
416 config KALLSYMS_EXTRA_PASS
417 bool "Do an extra kallsyms pass"
420 If kallsyms is not working correctly, the build will fail with
421 inconsistent kallsyms data. If that occurs, log a bug report and
422 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
423 Always say N here unless you find a bug in kallsyms, which must be
424 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
425 you wait for kallsyms to be fixed.
429 bool "Support for hot-pluggable devices" if EMBEDDED
432 This option is provided for the case where no hotplug or uevent
433 capabilities is wanted by the kernel. You should only consider
434 disabling this option for embedded systems that do not use modules, a
435 dynamic /dev tree, or dynamic device discovery. Just say Y.
439 bool "Enable support for printk" if EMBEDDED
441 This option enables normal printk support. Removing it
442 eliminates most of the message strings from the kernel image
443 and makes the kernel more or less silent. As this makes it
444 very difficult to diagnose system problems, saying N here is
445 strongly discouraged.
448 bool "BUG() support" if EMBEDDED
451 Disabling this option eliminates support for BUG and WARN, reducing
452 the size of your kernel image and potentially quietly ignoring
453 numerous fatal conditions. You should only consider disabling this
454 option for embedded systems with no facilities for reporting errors.
459 bool "Enable ELF core dumps" if EMBEDDED
461 Enable support for generating core dumps. Disabling saves about 4k.
465 bool "Enable full-sized data structures for core" if EMBEDDED
467 Disabling this option reduces the size of miscellaneous core
468 kernel data structures. This saves memory on small machines,
469 but may reduce performance.
472 bool "Enable futex support" if EMBEDDED
476 Disabling this option will cause the kernel to be built without
477 support for "fast userspace mutexes". The resulting kernel may not
478 run glibc-based applications correctly.
481 bool "Enable eventpoll support" if EMBEDDED
484 Disabling this option will cause the kernel to be built without
485 support for epoll family of system calls.
488 bool "Use full shmem filesystem" if EMBEDDED
492 The shmem is an internal filesystem used to manage shared memory.
493 It is backed by swap and manages resource limits. It is also exported
494 to userspace as tmpfs if TMPFS is enabled. Disabling this
495 option replaces shmem and tmpfs with the much simpler ramfs code,
496 which may be appropriate on small systems without swap.
498 config VM_EVENT_COUNTERS
500 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
502 VM event counters are needed for event counts to be shown.
503 This option allows the disabling of the VM event counters
504 on EMBEDDED systems. /proc/vmstat will only show page counts
505 if VM event counters are disabled.
508 prompt "Choose SLAB allocator"
511 This option allows to select a slab allocator.
516 The regular slab allocator that is established and known to work
517 well in all environments. It organizes chache hot objects in
518 per cpu and per node queues. SLAB is the default choice for
522 depends on EXPERIMENTAL && !ARCH_USES_SLAB_PAGE_STRUCT
523 bool "SLUB (Unqueued Allocator)"
525 SLUB is a slab allocator that minimizes cache line usage
526 instead of managing queues of cached objects (SLAB approach).
527 Per cpu caching is realized using slabs of objects instead
528 of queues of objects. SLUB can use memory efficiently
529 way and has enhanced diagnostics.
533 # SLOB cannot support SMP because SLAB_DESTROY_BY_RCU does not work
536 depends on EMBEDDED && !SMP && !SPARSEMEM
537 bool "SLOB (Simple Allocator)"
539 SLOB replaces the SLAB allocator with a drastically simpler
540 allocator. SLOB is more space efficient that SLAB but does not
541 scale well (single lock for all operations) and is more susceptible
542 to fragmentation. SLOB it is a great choice to reduce
543 memory usage and code size for embedded systems.
547 endmenu # General setup
559 default 0 if BASE_FULL
560 default 1 if !BASE_FULL
562 menu "Loadable module support"
565 bool "Enable loadable module support"
567 Kernel modules are small pieces of compiled code which can
568 be inserted in the running kernel, rather than being
569 permanently built into the kernel. You use the "modprobe"
570 tool to add (and sometimes remove) them. If you say Y here,
571 many parts of the kernel can be built as modules (by
572 answering M instead of Y where indicated): this is most
573 useful for infrequently used options which are not required
574 for booting. For more information, see the man pages for
575 modprobe, lsmod, modinfo, insmod and rmmod.
577 If you say Y here, you will need to run "make
578 modules_install" to put the modules under /lib/modules/
579 where modprobe can find them (you may need to be root to do
585 bool "Module unloading"
588 Without this option you will not be able to unload any
589 modules (note that some modules may not be unloadable
590 anyway), which makes your kernel slightly smaller and
591 simpler. If unsure, say Y.
593 config MODULE_FORCE_UNLOAD
594 bool "Forced module unloading"
595 depends on MODULE_UNLOAD && EXPERIMENTAL
597 This option allows you to force a module to unload, even if the
598 kernel believes it is unsafe: the kernel will remove the module
599 without waiting for anyone to stop using it (using the -f option to
600 rmmod). This is mainly for kernel developers and desperate users.
604 bool "Module versioning support"
607 Usually, you have to use modules compiled with your kernel.
608 Saying Y here makes it sometimes possible to use modules
609 compiled for different kernels, by adding enough information
610 to the modules to (hopefully) spot any changes which would
611 make them incompatible with the kernel you are running. If
614 config MODULE_SRCVERSION_ALL
615 bool "Source checksum for all modules"
618 Modules which contain a MODULE_VERSION get an extra "srcversion"
619 field inserted into their modinfo section, which contains a
620 sum of the source files which made it. This helps maintainers
621 see exactly which source was used to build a module (since
622 others sometimes change the module source without updating
623 the version). With this option, such a "srcversion" field
624 will be created for all modules. If unsure, say N.
627 bool "Automatic kernel module loading"
630 Normally when you have selected some parts of the kernel to
631 be created as kernel modules, you must load them (using the
632 "modprobe" command) before you can use them. If you say Y
633 here, some parts of the kernel will be able to load modules
634 automatically: when a part of the kernel needs a module, it
635 runs modprobe with the appropriate arguments, thereby
636 loading the module if it is available. If unsure, say Y.
641 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
643 Need stop_machine() primitive.
647 source "block/Kconfig"
projects / linux-2.6 / blob