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25 drivers that have been replaced by something else, and/or are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_CPU_MONITOR
182 tristate "CKRM CPU Resoure Monitor"
183 depends on CKRM_CPU_SCHEDULE
186 Monitor CPU Resource Usage of the classes
188 Say N if unsure, Y to use the feature.
190 config CKRM_TYPE_SOCKETCLASS
191 bool "Class Manager for socket groups"
194 SOCKET provides the extensions for CKRM to track per socket
195 classes. This is the base to enable socket based resource
196 control for inbound connection control, bandwidth control etc.
200 config CKRM_RES_LISTENAQ
201 tristate "Multiple Accept Queues Resource Manager"
202 depends on CKRM_TYPE_SOCKETCLASS && ACCEPT_QUEUES
205 Provides a resource controller for CKRM to prioritize inbound
206 connection requests. See inbound control description for
207 "IP: TCP Multiple accept queues support". If you choose that
208 option choose this option to control the queue weights.
213 tristate "Vanilla Rule-based Classification Engine (RBCE)"
214 depends on CKRM && RCFS_FS
217 Provides an optional module to support creation of rules for automatic
218 classification of kernel objects. Rules are created/deleted/modified
219 through an rcfs interface. RBCE is not required for CKRM.
224 tristate "Enhanced Rule-based Classification Engine (RBCE)"
225 depends on CKRM && RCFS_FS && RELAYFS_FS && DELAY_ACCT
228 Provides an optional module to support creation of rules for automatic
229 classification of kernel objects, just like RBCE above. In addition,
230 CRBCE provides per-process delay data (requires DELAY_ACCT configured)
231 enabled) and makes information on significant kernel events available
232 to userspace tools through relayfs (requires RELAYFS_FS configured).
238 config BSD_PROCESS_ACCT_V3
239 bool "BSD Process Accounting version 3 file format"
240 depends on BSD_PROCESS_ACCT
243 If you say Y here, the process accounting information is written
244 in a new file format that also logs the process IDs of each
245 process and it's parent. Note that this file format is incompatible
246 with previous v0/v1/v2 file formats, so you will need updated tools
247 for processing it. A preliminary version of these tools is available
248 at <http://http://www.de.kernel.org/pub/linux/utils/acct/>.
252 bool "Sysctl support"
254 The sysctl interface provides a means of dynamically changing
255 certain kernel parameters and variables on the fly without requiring
256 a recompile of the kernel or reboot of the system. The primary
257 interface consists of a system call, but if you say Y to "/proc
258 file system support", a tree of modifiable sysctl entries will be
259 generated beneath the /proc/sys directory. They are explained in the
260 files in <file:Documentation/sysctl/>. Note that enabling this
261 option will enlarge the kernel by at least 8 KB.
263 As it is generally a good thing, you should say Y here unless
264 building a kernel for install/rescue disks or your system is very
268 bool "Auditing support"
269 default y if SECURITY_SELINUX
272 Enable auditing infrastructure that can be used with another
273 kernel subsystem, such as SELinux (which requires this for
274 logging of avc messages output). Does not do system-call
275 auditing without CONFIG_AUDITSYSCALL.
278 bool "Enable system-call auditing support"
279 depends on AUDIT && (X86 || PPC64 || ARCH_S390 || IA64)
280 default y if SECURITY_SELINUX
283 Enable low-overhead system-call auditing infrastructure that
284 can be used independently or with another kernel subsystem,
288 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
290 default 17 if ARCH_S390
291 default 16 if X86_NUMAQ || IA64
295 Select kernel log buffer size as a power of 2.
296 Defaults and Examples:
297 17 => 128 KB for S/390
298 16 => 64 KB for x86 NUMAQ or IA-64
300 14 => 16 KB for uniprocessor
305 bool "Support for hot-pluggable devices" if !ARCH_S390
308 Say Y here if you want to plug devices into your computer while
309 the system is running, and be able to use them quickly. In many
310 cases, the devices can likewise be unplugged at any time too.
312 One well known example of this is PCMCIA- or PC-cards, credit-card
313 size devices such as network cards, modems or hard drives which are
314 plugged into slots found on all modern laptop computers. Another
315 example, used on modern desktops as well as laptops, is USB.
317 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
318 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
319 Then your kernel will automatically call out to a user mode "policy
320 agent" (/sbin/hotplug) to load modules and set up software needed
321 to use devices as you hotplug them.
324 bool "Kernel .config support"
326 This option enables the complete Linux kernel ".config" file
327 contents to be saved in the kernel. It provides documentation
328 of which kernel options are used in a running kernel or in an
329 on-disk kernel. This information can be extracted from the kernel
330 image file with the script scripts/extract-ikconfig and used as
331 input to rebuild the current kernel or to build another kernel.
332 It can also be extracted from a running kernel by reading
333 /proc/config.gz if enabled (below).
336 bool "Enable access to .config through /proc/config.gz"
337 depends on IKCONFIG && PROC_FS
339 This option enables access to the kernel configuration file
340 through /proc/config.gz.
344 bool "Configure standard kernel features (for small systems)"
346 This option allows certain base kernel options and settings
347 to be disabled or tweaked. This is for specialized
348 environments which can tolerate a "non-standard" kernel.
349 Only use this if you really know what you are doing.
352 bool "Enable delay accounting (EXPERIMENTAL)"
354 In addition to counting frequency the total delay in ns is also
355 recorded. CPU delays are specified as cpu-wait and cpu-run.
356 I/O delays are recorded for memory and regular I/O.
357 Information is accessible through /proc/<pid>/delay.
361 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
364 Say Y here to let the kernel print out symbolic crash information and
365 symbolic stack backtraces. This increases the size of the kernel
366 somewhat, as all symbols have to be loaded into the kernel image.
369 bool "Include all symbols in kallsyms"
370 depends on DEBUG_KERNEL && KALLSYMS
372 Normally kallsyms only contains the symbols of functions, for nicer
373 OOPS messages. Some debuggers can use kallsyms for other
374 symbols too: say Y here to include all symbols, and you
375 don't care about adding 300k to the size of your kernel.
379 config KALLSYMS_EXTRA_PASS
380 bool "Do an extra kallsyms pass"
383 If kallsyms is not working correctly, the build will fail with
384 inconsistent kallsyms data. If that occurs, log a bug report and
385 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
386 Always say N here unless you find a bug in kallsyms, which must be
387 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
388 you wait for kallsyms to be fixed.
391 bool "Enable futex support" if EMBEDDED
394 Disabling this option will cause the kernel to be built without
395 support for "fast userspace mutexes". The resulting kernel may not
396 run glibc-based applications correctly.
399 bool "Enable eventpoll support" if EMBEDDED
402 Disabling this option will cause the kernel to be built without
403 support for epoll family of system calls.
405 source "drivers/block/Kconfig.iosched"
407 config CC_OPTIMIZE_FOR_SIZE
408 bool "Optimize for size"
409 default y if ARM || H8300
412 Enabling this option will pass "-Os" instead of "-O2" to gcc
413 resulting in a smaller kernel.
415 WARNING: some versions of gcc may generate incorrect code with this
416 option. If problems are observed, a gcc upgrade may be needed.
420 endmenu # General setup
423 menu "Loadable module support"
426 bool "Enable loadable module support"
428 Kernel modules are small pieces of compiled code which can
429 be inserted in the running kernel, rather than being
430 permanently built into the kernel. You use the "modprobe"
431 tool to add (and sometimes remove) them. If you say Y here,
432 many parts of the kernel can be built as modules (by
433 answering M instead of Y where indicated): this is most
434 useful for infrequently used options which are not required
435 for booting. For more information, see the man pages for
436 modprobe, lsmod, modinfo, insmod and rmmod.
438 If you say Y here, you will need to run "make
439 modules_install" to put the modules under /lib/modules/
440 where modprobe can find them (you may need to be root to do
446 bool "Module unloading"
449 Without this option you will not be able to unload any
450 modules (note that some modules may not be unloadable
451 anyway), which makes your kernel slightly smaller and
452 simpler. If unsure, say Y.
454 config MODULE_FORCE_UNLOAD
455 bool "Forced module unloading"
456 depends on MODULE_UNLOAD && EXPERIMENTAL
458 This option allows you to force a module to unload, even if the
459 kernel believes it is unsafe: the kernel will remove the module
460 without waiting for anyone to stop using it (using the -f option to
461 rmmod). This is mainly for kernel developers and desperate users.
464 config OBSOLETE_MODPARM
469 You need this option to use module parameters on modules which
470 have not been converted to the new module parameter system yet.
474 bool "Module versioning support (EXPERIMENTAL)"
475 depends on MODULES && EXPERIMENTAL
477 Usually, you have to use modules compiled with your kernel.
478 Saying Y here makes it sometimes possible to use modules
479 compiled for different kernels, by adding enough information
480 to the modules to (hopefully) spot any changes which would
481 make them incompatible with the kernel you are running. If
485 bool "Module signature verification (EXPERIMENTAL)"
486 depends on MODULES && EXPERIMENTAL
488 select CRYPTO_SIGNATURE
490 Check modules for valid signatures upon load.
492 config MODULE_SIG_FORCE
493 bool "Required modules to be validly signed (EXPERIMENTAL)"
494 depends on MODULE_SIG
496 Reject unsigned modules or signed modules for which we don't have a
500 bool "Automatic kernel module loading"
503 Normally when you have selected some parts of the kernel to
504 be created as kernel modules, you must load them (using the
505 "modprobe" command) before you can use them. If you say Y
506 here, some parts of the kernel will be able to load modules
507 automatically: when a part of the kernel needs a module, it
508 runs modprobe with the appropriate arguments, thereby
509 loading the module if it is available. If unsure, say Y.
514 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
516 Need stop_machine() primitive.