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25 drivers that have been replaced by something else, and/or are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.
81 Inter Process Communication is a suite of library functions and
82 system calls which let processes (running programs) synchronize and
83 exchange information. It is generally considered to be a good thing,
84 and some programs won't run unless you say Y here. In particular, if
85 you want to run the DOS emulator dosemu under Linux (read the
86 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
87 you'll need to say Y here.
89 You can find documentation about IPC with "info ipc" and also in
90 section 6.4 of the Linux Programmer's Guide, available from
91 <http://www.tldp.org/guides.html>.
94 bool "POSIX Message Queues"
95 depends on NET && EXPERIMENTAL
97 POSIX variant of message queues is a part of IPC. In POSIX message
98 queues every message has a priority which decides about succession
99 of receiving it by a process. If you want to compile and run
100 programs written e.g. for Solaris with use of its POSIX message
101 queues (functions mq_*) say Y here. To use this feature you will
102 also need mqueue library, available from
103 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
105 POSIX message queues are visible as a filesystem called 'mqueue'
106 and can be mounted somewhere if you want to do filesystem
107 operations on message queues.
111 config BSD_PROCESS_ACCT
112 bool "BSD Process Accounting"
114 If you say Y here, a user level program will be able to instruct the
115 kernel (via a special system call) to write process accounting
116 information to a file: whenever a process exits, information about
117 that process will be appended to the file by the kernel. The
118 information includes things such as creation time, owning user,
119 command name, memory usage, controlling terminal etc. (the complete
120 list is in the struct acct in <file:include/linux/acct.h>). It is
121 up to the user level program to do useful things with this
122 information. This is generally a good idea, so say Y.
124 menu "Class Based Kernel Resource Management"
127 bool "Class Based Kernel Resource Management Core"
128 depends on EXPERIMENTAL
130 Class-based Kernel Resource Management is a framework for controlling
131 and monitoring resource allocation of user-defined groups of tasks or
132 incoming socket connections. For more information, please visit
135 If you say Y here, enable the Resource Class File System and atleast
136 one of the resource controllers below. Say N if you are unsure.
139 tristate "Resource Class File System (User API)"
142 RCFS is the filesystem API for CKRM. This separate configuration
143 option is provided only for debugging and will eventually disappear
144 since rcfs will be automounted whenever CKRM is configured.
146 Say N if unsure, Y if you've enabled CKRM, M to debug rcfs
149 config CKRM_TYPE_TASKCLASS
150 bool "Class Manager for Task Groups"
153 TASKCLASS provides the extensions for CKRM to track task classes
154 This is the base to enable task class based resource control for
155 cpu, memory and disk I/O.
159 config CKRM_RES_NUMTASKS
160 tristate "Number of Tasks Resource Manager"
161 depends on CKRM_TYPE_TASKCLASS
164 Provides a Resource Controller for CKRM that allows limiting no of
165 tasks a task class can have.
167 Say N if unsure, Y to use the feature.
169 config CKRM_TYPE_SOCKETCLASS
170 bool "Class Manager for socket groups"
173 SOCKET provides the extensions for CKRM to track per socket
174 classes. This is the base to enable socket based resource
175 control for inbound connection control, bandwidth control etc.
179 config CKRM_RES_LISTENAQ
180 tristate "Multiple Accept Queues Resource Manager"
181 depends on CKRM_TYPE_SOCKETCLASS && ACCEPT_QUEUES
184 Provides a resource controller for CKRM to prioritize inbound
185 connection requests. See inbound control description for
186 "IP: TCP Multiple accept queues support". If you choose that
187 option choose this option to control the queue weights.
193 config BSD_PROCESS_ACCT_V3
194 bool "BSD Process Accounting version 3 file format"
195 depends on BSD_PROCESS_ACCT
198 If you say Y here, the process accounting information is written
199 in a new file format that also logs the process IDs of each
200 process and it's parent. Note that this file format is incompatible
201 with previous v0/v1/v2 file formats, so you will need updated tools
202 for processing it. A preliminary version of these tools is available
203 at <http://http://www.de.kernel.org/pub/linux/utils/acct/>.
207 bool "Sysctl support"
209 The sysctl interface provides a means of dynamically changing
210 certain kernel parameters and variables on the fly without requiring
211 a recompile of the kernel or reboot of the system. The primary
212 interface consists of a system call, but if you say Y to "/proc
213 file system support", a tree of modifiable sysctl entries will be
214 generated beneath the /proc/sys directory. They are explained in the
215 files in <file:Documentation/sysctl/>. Note that enabling this
216 option will enlarge the kernel by at least 8 KB.
218 As it is generally a good thing, you should say Y here unless
219 building a kernel for install/rescue disks or your system is very
223 bool "Auditing support"
224 default y if SECURITY_SELINUX
227 Enable auditing infrastructure that can be used with another
228 kernel subsystem, such as SELinux (which requires this for
229 logging of avc messages output). Does not do system-call
230 auditing without CONFIG_AUDITSYSCALL.
233 bool "Enable system-call auditing support"
234 depends on AUDIT && (X86 || PPC64 || ARCH_S390)
235 default y if SECURITY_SELINUX
238 Enable low-overhead system-call auditing infrastructure that
239 can be used independently or with another kernel subsystem,
243 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
245 default 17 if ARCH_S390
246 default 16 if X86_NUMAQ || IA64
250 Select kernel log buffer size as a power of 2.
251 Defaults and Examples:
252 17 => 128 KB for S/390
253 16 => 64 KB for x86 NUMAQ or IA-64
255 14 => 16 KB for uniprocessor
260 bool "Support for hot-pluggable devices" if !ARCH_S390
263 Say Y here if you want to plug devices into your computer while
264 the system is running, and be able to use them quickly. In many
265 cases, the devices can likewise be unplugged at any time too.
267 One well known example of this is PCMCIA- or PC-cards, credit-card
268 size devices such as network cards, modems or hard drives which are
269 plugged into slots found on all modern laptop computers. Another
270 example, used on modern desktops as well as laptops, is USB.
272 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
273 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
274 Then your kernel will automatically call out to a user mode "policy
275 agent" (/sbin/hotplug) to load modules and set up software needed
276 to use devices as you hotplug them.
279 bool "Kernel .config support"
281 This option enables the complete Linux kernel ".config" file
282 contents, information on compiler used to build the kernel,
283 kernel running when this kernel was built and kernel version
284 from Makefile to be saved in the kernel. It provides documentation
285 of which kernel options are used in a running kernel or in an
286 on-disk kernel. This information can be extracted from the kernel
287 image file with the script scripts/extract-ikconfig and used as
288 input to rebuild the current kernel or to build another kernel.
289 It can also be extracted from a running kernel by reading
290 /proc/config.gz and /proc/config_built_with, if enabled (below).
291 /proc/config.gz will list the configuration that was used
292 to build the kernel and /proc/config_built_with will list
293 information on the compiler and host machine that was used to
297 bool "Enable access to .config through /proc/config.gz"
298 depends on IKCONFIG && PROC_FS
300 This option enables access to kernel configuration file and build
301 information through /proc/config.gz.
305 bool "Configure standard kernel features (for small systems)"
307 This option allows certain base kernel options and settings
308 to be disabled or tweaked. This is for specialized
309 environments which can tolerate a "non-standard" kernel.
310 Only use this if you really know what you are doing.
313 bool "Enable delay accounting (EXPERIMENTAL)"
315 In addition to counting frequency the total delay in ns is also
316 recorded. CPU delays are specified as cpu-wait and cpu-run. Memory
317 delay is recorded for minor and major faults. Information is
318 accessible through /proc/<pid>/delay.
322 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
325 Say Y here to let the kernel print out symbolic crash information and
326 symbolic stack backtraces. This increases the size of the kernel
327 somewhat, as all symbols have to be loaded into the kernel image.
330 bool "Include all symbols in kallsyms"
331 depends on DEBUG_KERNEL && KALLSYMS
333 Normally kallsyms only contains the symbols of functions, for nicer
334 OOPS messages. Some debuggers can use kallsyms for other
335 symbols too: say Y here to include all symbols, and you
336 don't care about adding 300k to the size of your kernel.
341 bool "Enable futex support" if EMBEDDED
344 Disabling this option will cause the kernel to be built without
345 support for "fast userspace mutexes". The resulting kernel may not
346 run glibc-based applications correctly.
349 bool "Enable eventpoll support" if EMBEDDED
352 Disabling this option will cause the kernel to be built without
353 support for epoll family of system calls.
355 source "drivers/block/Kconfig.iosched"
357 config CC_OPTIMIZE_FOR_SIZE
358 bool "Optimize for size"
359 default y if ARM || H8300
362 Enabling this option will pass "-Os" instead of "-O2" to gcc
363 resulting in a smaller kernel.
365 WARNING: some versions of gcc may generate incorrect code with this
366 option. If problems are observed, a gcc upgrade may be needed.
370 endmenu # General setup
373 menu "Loadable module support"
376 bool "Enable loadable module support"
378 Kernel modules are small pieces of compiled code which can
379 be inserted in the running kernel, rather than being
380 permanently built into the kernel. You use the "modprobe"
381 tool to add (and sometimes remove) them. If you say Y here,
382 many parts of the kernel can be built as modules (by
383 answering M instead of Y where indicated): this is most
384 useful for infrequently used options which are not required
385 for booting. For more information, see the man pages for
386 modprobe, lsmod, modinfo, insmod and rmmod.
388 If you say Y here, you will need to run "make
389 modules_install" to put the modules under /lib/modules/
390 where modprobe can find them (you may need to be root to do
396 bool "Module unloading"
399 Without this option you will not be able to unload any
400 modules (note that some modules may not be unloadable
401 anyway), which makes your kernel slightly smaller and
402 simpler. If unsure, say Y.
404 config MODULE_FORCE_UNLOAD
405 bool "Forced module unloading"
406 depends on MODULE_UNLOAD && EXPERIMENTAL
408 This option allows you to force a module to unload, even if the
409 kernel believes it is unsafe: the kernel will remove the module
410 without waiting for anyone to stop using it (using the -f option to
411 rmmod). This is mainly for kernel developers and desperate users.
414 config OBSOLETE_MODPARM
419 You need this option to use module parameters on modules which
420 have not been converted to the new module parameter system yet.
424 bool "Module versioning support (EXPERIMENTAL)"
425 depends on MODULES && EXPERIMENTAL
427 Usually, you have to use modules compiled with your kernel.
428 Saying Y here makes it sometimes possible to use modules
429 compiled for different kernels, by adding enough information
430 to the modules to (hopefully) spot any changes which would
431 make them incompatible with the kernel you are running. If
435 bool "Automatic kernel module loading"
438 Normally when you have selected some parts of the kernel to
439 be created as kernel modules, you must load them (using the
440 "modprobe" command) before you can use them. If you say Y
441 here, some parts of the kernel will be able to load modules
442 automatically: when a part of the kernel needs a module, it
443 runs modprobe with the appropriate arguments, thereby
444 loading the module if it is available. If unsure, say Y.
449 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
451 Need stop_machine() primitive.