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33 drivers that have been replaced by something else, and/or are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>.
123 config SYSVIPC_SYSCTL
130 bool "POSIX Message Queues"
131 depends on NET && EXPERIMENTAL
133 POSIX variant of message queues is a part of IPC. In POSIX message
134 queues every message has a priority which decides about succession
135 of receiving it by a process. If you want to compile and run
136 programs written e.g. for Solaris with use of its POSIX message
137 queues (functions mq_*) say Y here.
139 POSIX message queues are visible as a filesystem called 'mqueue'
140 and can be mounted somewhere if you want to do filesystem
141 operations on message queues.
145 config BSD_PROCESS_ACCT
146 bool "BSD Process Accounting"
148 If you say Y here, a user level program will be able to instruct the
149 kernel (via a special system call) to write process accounting
150 information to a file: whenever a process exits, information about
151 that process will be appended to the file by the kernel. The
152 information includes things such as creation time, owning user,
153 command name, memory usage, controlling terminal etc. (the complete
154 list is in the struct acct in <file:include/linux/acct.h>). It is
155 up to the user level program to do useful things with this
156 information. This is generally a good idea, so say Y.
158 config BSD_PROCESS_ACCT_V3
159 bool "BSD Process Accounting version 3 file format"
160 depends on BSD_PROCESS_ACCT
163 If you say Y here, the process accounting information is written
164 in a new file format that also logs the process IDs of each
165 process and it's parent. Note that this file format is incompatible
166 with previous v0/v1/v2 file formats, so you will need updated tools
167 for processing it. A preliminary version of these tools is available
168 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
171 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
175 Export selected statistics for tasks/processes through the
176 generic netlink interface. Unlike BSD process accounting, the
177 statistics are available during the lifetime of tasks/processes as
178 responses to commands. Like BSD accounting, they are sent to user
183 config TASK_DELAY_ACCT
184 bool "Enable per-task delay accounting (EXPERIMENTAL)"
187 Collect information on time spent by a task waiting for system
188 resources like cpu, synchronous block I/O completion and swapping
189 in pages. Such statistics can help in setting a task's priorities
190 relative to other tasks for cpu, io, rss limits etc.
195 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
198 Collect extended task accounting data and send the data
199 to userland for processing over the taskstats interface.
203 config TASK_IO_ACCOUNTING
204 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
205 depends on TASK_XACCT
207 Collect information on the number of bytes of storage I/O which this
213 bool "User Namespaces (EXPERIMENTAL)"
215 depends on EXPERIMENTAL
217 Support user namespaces. This allows containers, i.e.
218 vservers, to use user namespaces to provide different
219 user info for different servers. If unsure, say N.
222 bool "Auditing support"
225 Enable auditing infrastructure that can be used with another
226 kernel subsystem, such as SELinux (which requires this for
227 logging of avc messages output). Does not do system-call
228 auditing without CONFIG_AUDITSYSCALL.
231 bool "Enable system-call auditing support"
232 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
233 default y if SECURITY_SELINUX
235 Enable low-overhead system-call auditing infrastructure that
236 can be used independently or with another kernel subsystem,
237 such as SELinux. To use audit's filesystem watch feature, please
238 ensure that INOTIFY is configured.
241 tristate "Kernel .config support"
243 This option enables the complete Linux kernel ".config" file
244 contents to be saved in the kernel. It provides documentation
245 of which kernel options are used in a running kernel or in an
246 on-disk kernel. This information can be extracted from the kernel
247 image file with the script scripts/extract-ikconfig and used as
248 input to rebuild the current kernel or to build another kernel.
249 It can also be extracted from a running kernel by reading
250 /proc/config.gz if enabled (below).
253 bool "Enable access to .config through /proc/config.gz"
254 depends on IKCONFIG && PROC_FS
256 This option enables access to the kernel configuration file
257 through /proc/config.gz.
260 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
262 default 17 if S390 || LOCKDEP
263 default 16 if X86_NUMAQ || IA64
267 Select kernel log buffer size as a power of 2.
268 Defaults and Examples:
269 17 => 128 KB for S/390
270 16 => 64 KB for x86 NUMAQ or IA-64
272 14 => 16 KB for uniprocessor
277 bool "Cpuset support"
280 This option will let you create and manage CPUSETs which
281 allow dynamically partitioning a system into sets of CPUs and
282 Memory Nodes and assigning tasks to run only within those sets.
283 This is primarily useful on large SMP or NUMA systems.
287 config SYSFS_DEPRECATED
288 bool "Create deprecated sysfs files"
291 This option creates deprecated symlinks such as the
292 "device"-link, the <subsystem>:<name>-link, and the
293 "bus"-link. It may also add deprecated key in the
295 None of these features or values should be used today, as
296 they export driver core implementation details to userspace
297 or export properties which can't be kept stable across kernel
300 If enabled, this option will also move any device structures
301 that belong to a class, back into the /sys/class hierarchy, in
302 order to support older versions of udev.
304 If you are using a distro that was released in 2006 or later,
305 it should be safe to say N here.
308 bool "Kernel->user space relay support (formerly relayfs)"
310 This option enables support for relay interface support in
311 certain file systems (such as debugfs).
312 It is designed to provide an efficient mechanism for tools and
313 facilities to relay large amounts of data from kernel space to
318 config BLK_DEV_INITRD
319 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
320 depends on BROKEN || !FRV
322 The initial RAM filesystem is a ramfs which is loaded by the
323 boot loader (loadlin or lilo) and that is mounted as root
324 before the normal boot procedure. It is typically used to
325 load modules needed to mount the "real" root file system,
326 etc. See <file:Documentation/initrd.txt> for details.
328 If RAM disk support (BLK_DEV_RAM) is also included, this
329 also enables initial RAM disk (initrd) support and adds
330 15 Kbytes (more on some other architectures) to the kernel size.
340 config CC_OPTIMIZE_FOR_SIZE
341 bool "Optimize for size (Look out for broken compilers!)"
343 depends on ARM || H8300 || EXPERIMENTAL
345 Enabling this option will pass "-Os" instead of "-O2" to gcc
346 resulting in a smaller kernel.
348 WARNING: some versions of gcc may generate incorrect code with this
349 option. If problems are observed, a gcc upgrade may be needed.
357 bool "Configure standard kernel features (for small systems)"
359 This option allows certain base kernel options and settings
360 to be disabled or tweaked. This is for specialized
361 environments which can tolerate a "non-standard" kernel.
362 Only use this if you really know what you are doing.
365 bool "Enable 16-bit UID system calls" if EMBEDDED
366 depends on ARM || BFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
369 This enables the legacy 16-bit UID syscall wrappers.
371 config SYSCTL_SYSCALL
372 bool "Sysctl syscall support" if EMBEDDED
376 sys_sysctl uses binary paths that have been found challenging
377 to properly maintain and use. The interface in /proc/sys
378 using paths with ascii names is now the primary path to this
381 Almost nothing using the binary sysctl interface so if you are
382 trying to save some space it is probably safe to disable this,
383 making your kernel marginally smaller.
385 If unsure say Y here.
388 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
391 Say Y here to let the kernel print out symbolic crash information and
392 symbolic stack backtraces. This increases the size of the kernel
393 somewhat, as all symbols have to be loaded into the kernel image.
396 bool "Include all symbols in kallsyms"
397 depends on DEBUG_KERNEL && KALLSYMS
399 Normally kallsyms only contains the symbols of functions, for nicer
400 OOPS messages. Some debuggers can use kallsyms for other
401 symbols too: say Y here to include all symbols, if you need them
402 and you don't care about adding 300k to the size of your kernel.
406 config KALLSYMS_EXTRA_PASS
407 bool "Do an extra kallsyms pass"
410 If kallsyms is not working correctly, the build will fail with
411 inconsistent kallsyms data. If that occurs, log a bug report and
412 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
413 Always say N here unless you find a bug in kallsyms, which must be
414 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
415 you wait for kallsyms to be fixed.
419 bool "Support for hot-pluggable devices" if EMBEDDED
422 This option is provided for the case where no hotplug or uevent
423 capabilities is wanted by the kernel. You should only consider
424 disabling this option for embedded systems that do not use modules, a
425 dynamic /dev tree, or dynamic device discovery. Just say Y.
429 bool "Enable support for printk" if EMBEDDED
431 This option enables normal printk support. Removing it
432 eliminates most of the message strings from the kernel image
433 and makes the kernel more or less silent. As this makes it
434 very difficult to diagnose system problems, saying N here is
435 strongly discouraged.
438 bool "BUG() support" if EMBEDDED
441 Disabling this option eliminates support for BUG and WARN, reducing
442 the size of your kernel image and potentially quietly ignoring
443 numerous fatal conditions. You should only consider disabling this
444 option for embedded systems with no facilities for reporting errors.
449 bool "Enable ELF core dumps" if EMBEDDED
451 Enable support for generating core dumps. Disabling saves about 4k.
455 bool "Enable full-sized data structures for core" if EMBEDDED
457 Disabling this option reduces the size of miscellaneous core
458 kernel data structures. This saves memory on small machines,
459 but may reduce performance.
462 bool "Enable futex support" if EMBEDDED
466 Disabling this option will cause the kernel to be built without
467 support for "fast userspace mutexes". The resulting kernel may not
468 run glibc-based applications correctly.
471 bool "Enable anonymous inode source" if EMBEDDED
474 Anonymous inode source for pseudo-files like epoll, signalfd,
480 bool "Enable eventpoll support" if EMBEDDED
482 depends on ANON_INODES
484 Disabling this option will cause the kernel to be built without
485 support for epoll family of system calls.
488 bool "Enable signalfd() system call" if EMBEDDED
489 depends on ANON_INODES
492 Enable the signalfd() system call that allows to receive signals
493 on a file descriptor.
498 bool "Enable timerfd() system call" if EMBEDDED
499 depends on ANON_INODES
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
509 depends on ANON_INODES
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