2 menu "Code maturity level options"
5 bool "Prompt for development and/or incomplete code/drivers"
7 Some of the various things that Linux supports (such as network
8 drivers, file systems, network protocols, etc.) can be in a state
9 of development where the functionality, stability, or the level of
10 testing is not yet high enough for general use. This is usually
11 known as the "alpha-test" phase among developers. If a feature is
12 currently in alpha-test, then the developers usually discourage
13 uninformed widespread use of this feature by the general public to
14 avoid "Why doesn't this work?" type mail messages. However, active
15 testing and use of these systems is welcomed. Just be aware that it
16 may not meet the normal level of reliability or it may fail to work
17 in some special cases. Detailed bug reports from people familiar
18 with the kernel internals are usually welcomed by the developers
19 (before submitting bug reports, please read the documents
20 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
21 <file:Documentation/BUG-HUNTING>, and
22 <file:Documentation/oops-tracing.txt> in the kernel source).
24 This option will also make obsoleted drivers available. These are
25 drivers that have been replaced by something else, and/or are
26 scheduled to be removed in a future kernel release.
28 Unless you intend to help test and develop a feature or driver that
29 falls into this category, or you have a situation that requires
30 using these features, you should probably say N here, which will
31 cause the configurator to present you with fewer choices. If
32 you say Y here, you will be offered the choice of using features or
33 drivers that are currently considered to be in the alpha-test phase.
36 bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
39 Select this option if you don't even want to see the option
40 to configure known-broken drivers.
45 bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
48 Select this option if you don't have magic firmware for drivers that
55 depends on !CLEAN_COMPILE
60 depends on BROKEN || !SMP
69 bool "Support for paging of anonymous memory (swap)"
73 This option allows you to choose whether you want to have support
74 for socalled swap devices or swap files in your kernel that are
75 used to provide more virtual memory than the actual RAM present
76 in your computer. If unsure say Y.
82 Inter Process Communication is a suite of library functions and
83 system calls which let processes (running programs) synchronize and
84 exchange information. It is generally considered to be a good thing,
85 and some programs won't run unless you say Y here. In particular, if
86 you want to run the DOS emulator dosemu under Linux (read the
87 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
88 you'll need to say Y here.
89 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
90 you'll need to say Y here.
92 You can find documentation about IPC with "info ipc" and also in
93 section 6.4 of the Linux Programmer's Guide, available from
94 <http://www.tldp.org/guides.html>.
97 bool "POSIX Message Queues"
98 depends on NET && EXPERIMENTAL
100 POSIX variant of message queues is a part of IPC. In POSIX message
101 queues every message has a priority which decides about succession
102 of receiving it by a process. If you want to compile and run
103 programs written e.g. for Solaris with use of its POSIX message
104 queues (functions mq_*) say Y here. To use this feature you will
105 also need mqueue library, available from
106 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
108 POSIX message queues are visible as a filesystem called 'mqueue'
109 and can be mounted somewhere if you want to do filesystem
110 operations on message queues.
114 config BSD_PROCESS_ACCT
115 bool "BSD Process Accounting"
117 If you say Y here, a user level program will be able to instruct the
118 kernel (via a special system call) to write process accounting
119 information to a file: whenever a process exits, information about
120 that process will be appended to the file by the kernel. The
121 information includes things such as creation time, owning user,
122 command name, memory usage, controlling terminal etc. (the complete
123 list is in the struct acct in <file:include/linux/acct.h>). It is
124 up to the user level program to do useful things with this
125 information. This is generally a good idea, so say Y.
127 menu "Class Based Kernel Resource Management"
130 bool "Class Based Kernel Resource Management Core"
131 depends on EXPERIMENTAL
133 Class-based Kernel Resource Management is a framework for controlling
134 and monitoring resource allocation of user-defined groups of tasks or
135 incoming socket connections. For more information, please visit
138 If you say Y here, enable the Resource Class File System and atleast
139 one of the resource controllers below. Say N if you are unsure.
142 tristate "Resource Class File System (User API)"
145 RCFS is the filesystem API for CKRM. This separate configuration
146 option is provided only for debugging and will eventually disappear
147 since rcfs will be automounted whenever CKRM is configured.
149 Say N if unsure, Y if you've enabled CKRM, M to debug rcfs
152 config CKRM_TYPE_TASKCLASS
153 bool "Class Manager for Task Groups"
156 TASKCLASS provides the extensions for CKRM to track task classes
157 This is the base to enable task class based resource control for
158 cpu, memory and disk I/O.
162 config CKRM_RES_NUMTASKS
163 tristate "Number of Tasks Resource Manager"
164 depends on CKRM_TYPE_TASKCLASS
167 Provides a Resource Controller for CKRM that allows limiting no of
168 tasks a task class can have.
170 Say N if unsure, Y to use the feature.
172 config CKRM_CPU_SCHEDULE
173 bool "CKRM CPU scheduler"
174 depends on CKRM_TYPE_TASKCLASS
177 Use CKRM CPU scheduler instead of Linux Scheduler
179 Say N if unsure, Y to use the feature.
181 config CKRM_TYPE_SOCKETCLASS
182 bool "Class Manager for socket groups"
185 SOCKET provides the extensions for CKRM to track per socket
186 classes. This is the base to enable socket based resource
187 control for inbound connection control, bandwidth control etc.
191 config CKRM_RES_LISTENAQ
192 tristate "Multiple Accept Queues Resource Manager"
193 depends on CKRM_TYPE_SOCKETCLASS && ACCEPT_QUEUES
196 Provides a resource controller for CKRM to prioritize inbound
197 connection requests. See inbound control description for
198 "IP: TCP Multiple accept queues support". If you choose that
199 option choose this option to control the queue weights.
204 tristate "Vanilla Rule-based Classification Engine (RBCE)"
205 depends on CKRM && RCFS_FS
208 Provides an optional module to support creation of rules for automatic
209 classification of kernel objects. Rules are created/deleted/modified
210 through an rcfs interface. RBCE is not required for CKRM.
215 tristate "Enhanced Rule-based Classification Engine (RBCE)"
216 depends on CKRM && RCFS_FS && RELAYFS_FS && DELAY_ACCT
219 Provides an optional module to support creation of rules for automatic
220 classification of kernel objects, just like RBCE above. In addition,
221 CRBCE provides per-process delay data (requires DELAY_ACCT configured)
222 enabled) and makes information on significant kernel events available
223 to userspace tools through relayfs (requires RELAYFS_FS configured).
229 config BSD_PROCESS_ACCT_V3
230 bool "BSD Process Accounting version 3 file format"
231 depends on BSD_PROCESS_ACCT
234 If you say Y here, the process accounting information is written
235 in a new file format that also logs the process IDs of each
236 process and it's parent. Note that this file format is incompatible
237 with previous v0/v1/v2 file formats, so you will need updated tools
238 for processing it. A preliminary version of these tools is available
239 at <http://http://www.de.kernel.org/pub/linux/utils/acct/>.
242 bool "Sysctl support"
244 The sysctl interface provides a means of dynamically changing
245 certain kernel parameters and variables on the fly without requiring
246 a recompile of the kernel or reboot of the system. The primary
247 interface consists of a system call, but if you say Y to "/proc
248 file system support", a tree of modifiable sysctl entries will be
249 generated beneath the /proc/sys directory. They are explained in the
250 files in <file:Documentation/sysctl/>. Note that enabling this
251 option will enlarge the kernel by at least 8 KB.
253 As it is generally a good thing, you should say Y here unless
254 building a kernel for install/rescue disks or your system is very
258 bool "Auditing support"
259 default y if SECURITY_SELINUX
262 Enable auditing infrastructure that can be used with another
263 kernel subsystem, such as SELinux (which requires this for
264 logging of avc messages output). Does not do system-call
265 auditing without CONFIG_AUDITSYSCALL.
268 bool "Enable system-call auditing support"
269 depends on AUDIT && (X86 || PPC64 || ARCH_S390 || IA64)
270 default y if SECURITY_SELINUX
273 Enable low-overhead system-call auditing infrastructure that
274 can be used independently or with another kernel subsystem,
278 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
280 default 17 if ARCH_S390
281 default 16 if X86_NUMAQ || IA64
285 Select kernel log buffer size as a power of 2.
286 Defaults and Examples:
287 17 => 128 KB for S/390
288 16 => 64 KB for x86 NUMAQ or IA-64
290 14 => 16 KB for uniprocessor
295 bool "Support for hot-pluggable devices" if !ARCH_S390
298 Say Y here if you want to plug devices into your computer while
299 the system is running, and be able to use them quickly. In many
300 cases, the devices can likewise be unplugged at any time too.
302 One well known example of this is PCMCIA- or PC-cards, credit-card
303 size devices such as network cards, modems or hard drives which are
304 plugged into slots found on all modern laptop computers. Another
305 example, used on modern desktops as well as laptops, is USB.
307 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
308 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
309 Then your kernel will automatically call out to a user mode "policy
310 agent" (/sbin/hotplug) to load modules and set up software needed
311 to use devices as you hotplug them.
314 bool "Kernel .config support"
316 This option enables the complete Linux kernel ".config" file
317 contents to be saved in the kernel. It provides documentation
318 of which kernel options are used in a running kernel or in an
319 on-disk kernel. This information can be extracted from the kernel
320 image file with the script scripts/extract-ikconfig and used as
321 input to rebuild the current kernel or to build another kernel.
322 It can also be extracted from a running kernel by reading
323 /proc/config.gz if enabled (below).
326 bool "Enable access to .config through /proc/config.gz"
327 depends on IKCONFIG && PROC_FS
329 This option enables access to the kernel configuration file
330 through /proc/config.gz.
334 bool "Configure standard kernel features (for small systems)"
336 This option allows certain base kernel options and settings
337 to be disabled or tweaked. This is for specialized
338 environments which can tolerate a "non-standard" kernel.
339 Only use this if you really know what you are doing.
342 bool "Enable delay accounting (EXPERIMENTAL)"
344 In addition to counting frequency the total delay in ns is also
345 recorded. CPU delays are specified as cpu-wait and cpu-run.
346 I/O delays are recorded for memory and regular I/O.
347 Information is accessible through /proc/<pid>/delay.
351 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
354 Say Y here to let the kernel print out symbolic crash information and
355 symbolic stack backtraces. This increases the size of the kernel
356 somewhat, as all symbols have to be loaded into the kernel image.
359 bool "Include all symbols in kallsyms"
360 depends on DEBUG_KERNEL && KALLSYMS
362 Normally kallsyms only contains the symbols of functions, for nicer
363 OOPS messages. Some debuggers can use kallsyms for other
364 symbols too: say Y here to include all symbols, and you
365 don't care about adding 300k to the size of your kernel.
369 config KALLSYMS_EXTRA_PASS
370 bool "Do an extra kallsyms pass"
373 If kallsyms is not working correctly, the build will fail with
374 inconsistent kallsyms data. If that occurs, log a bug report and
375 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
376 Always say N here unless you find a bug in kallsyms, which must be
377 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
378 you wait for kallsyms to be fixed.
381 bool "Enable futex support" if EMBEDDED
384 Disabling this option will cause the kernel to be built without
385 support for "fast userspace mutexes". The resulting kernel may not
386 run glibc-based applications correctly.
389 bool "Enable eventpoll support" if EMBEDDED
392 Disabling this option will cause the kernel to be built without
393 support for epoll family of system calls.
395 source "drivers/block/Kconfig.iosched"
397 config CC_OPTIMIZE_FOR_SIZE
398 bool "Optimize for size"
399 default y if ARM || H8300
402 Enabling this option will pass "-Os" instead of "-O2" to gcc
403 resulting in a smaller kernel.
405 WARNING: some versions of gcc may generate incorrect code with this
406 option. If problems are observed, a gcc upgrade may be needed.
410 endmenu # General setup
413 menu "Loadable module support"
416 bool "Enable loadable module support"
418 Kernel modules are small pieces of compiled code which can
419 be inserted in the running kernel, rather than being
420 permanently built into the kernel. You use the "modprobe"
421 tool to add (and sometimes remove) them. If you say Y here,
422 many parts of the kernel can be built as modules (by
423 answering M instead of Y where indicated): this is most
424 useful for infrequently used options which are not required
425 for booting. For more information, see the man pages for
426 modprobe, lsmod, modinfo, insmod and rmmod.
428 If you say Y here, you will need to run "make
429 modules_install" to put the modules under /lib/modules/
430 where modprobe can find them (you may need to be root to do
436 bool "Module unloading"
439 Without this option you will not be able to unload any
440 modules (note that some modules may not be unloadable
441 anyway), which makes your kernel slightly smaller and
442 simpler. If unsure, say Y.
444 config MODULE_FORCE_UNLOAD
445 bool "Forced module unloading"
446 depends on MODULE_UNLOAD && EXPERIMENTAL
448 This option allows you to force a module to unload, even if the
449 kernel believes it is unsafe: the kernel will remove the module
450 without waiting for anyone to stop using it (using the -f option to
451 rmmod). This is mainly for kernel developers and desperate users.
454 config OBSOLETE_MODPARM
459 You need this option to use module parameters on modules which
460 have not been converted to the new module parameter system yet.
464 bool "Module versioning support (EXPERIMENTAL)"
465 depends on MODULES && EXPERIMENTAL
467 Usually, you have to use modules compiled with your kernel.
468 Saying Y here makes it sometimes possible to use modules
469 compiled for different kernels, by adding enough information
470 to the modules to (hopefully) spot any changes which would
471 make them incompatible with the kernel you are running. If
475 bool "Module signature verification (EXPERIMENTAL)"
476 depends on MODULES && EXPERIMENTAL
478 select CRYPTO_SIGNATURE
480 Check modules for valid signatures upon load.
482 config MODULE_SIG_FORCE
483 bool "Required modules to be validly signed (EXPERIMENTAL)"
484 depends on MODULE_SIG
486 Reject unsigned modules or signed modules for which we don't have a
490 bool "Automatic kernel module loading"
493 Normally when you have selected some parts of the kernel to
494 be created as kernel modules, you must load them (using the
495 "modprobe" command) before you can use them. If you say Y
496 here, some parts of the kernel will be able to load modules
497 automatically: when a part of the kernel needs a module, it
498 runs modprobe with the appropriate arguments, thereby
499 loading the module if it is available. If unsure, say Y.
504 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
506 Need stop_machine() primitive.