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1config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
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9config DEFCONFIG_LIST
10 string
b2670eac 11 depends on !UML
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12 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
16 default "arch/$ARCH/defconfig"
17
ff0cfc66 18menu "General setup"
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19
20config EXPERIMENTAL
21 bool "Prompt for development and/or incomplete code/drivers"
22 ---help---
23 Some of the various things that Linux supports (such as network
24 drivers, file systems, network protocols, etc.) can be in a state
25 of development where the functionality, stability, or the level of
26 testing is not yet high enough for general use. This is usually
27 known as the "alpha-test" phase among developers. If a feature is
28 currently in alpha-test, then the developers usually discourage
29 uninformed widespread use of this feature by the general public to
30 avoid "Why doesn't this work?" type mail messages. However, active
31 testing and use of these systems is welcomed. Just be aware that it
32 may not meet the normal level of reliability or it may fail to work
33 in some special cases. Detailed bug reports from people familiar
34 with the kernel internals are usually welcomed by the developers
35 (before submitting bug reports, please read the documents
36 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
37 <file:Documentation/BUG-HUNTING>, and
38 <file:Documentation/oops-tracing.txt> in the kernel source).
39
40 This option will also make obsoleted drivers available. These are
41 drivers that have been replaced by something else, and/or are
42 scheduled to be removed in a future kernel release.
43
44 Unless you intend to help test and develop a feature or driver that
45 falls into this category, or you have a situation that requires
46 using these features, you should probably say N here, which will
47 cause the configurator to present you with fewer choices. If
48 you say Y here, you will be offered the choice of using features or
49 drivers that are currently considered to be in the alpha-test phase.
50
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51config BROKEN
52 bool
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53
54config BROKEN_ON_SMP
55 bool
56 depends on BROKEN || !SMP
57 default y
58
59config LOCK_KERNEL
60 bool
61 depends on SMP || PREEMPT
62 default y
63
64config INIT_ENV_ARG_LIMIT
65 int
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66 default 32 if !UML
67 default 128 if UML
1da177e4 68 help
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69 Maximum of each of the number of arguments and environment
70 variables passed to init from the kernel command line.
1da177e4 71
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72
73config LOCALVERSION
74 string "Local version - append to kernel release"
75 help
76 Append an extra string to the end of your kernel version.
77 This will show up when you type uname, for example.
78 The string you set here will be appended after the contents of
79 any files with a filename matching localversion* in your
80 object and source tree, in that order. Your total string can
81 be a maximum of 64 characters.
82
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83config LOCALVERSION_AUTO
84 bool "Automatically append version information to the version string"
85 default y
86 help
87 This will try to automatically determine if the current tree is a
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88 release tree by looking for git tags that belong to the current
89 top of tree revision.
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90
91 A string of the format -gxxxxxxxx will be added to the localversion
6e5a5420 92 if a git-based tree is found. The string generated by this will be
aaebf433 93 appended after any matching localversion* files, and after the value
6e5a5420 94 set in CONFIG_LOCALVERSION.
aaebf433 95
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96 (The actual string used here is the first eight characters produced
97 by running the command:
98
99 $ git rev-parse --verify HEAD
100
101 which is done within the script "scripts/setlocalversion".)
aaebf433 102
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103config SWAP
104 bool "Support for paging of anonymous memory (swap)"
9361401e 105 depends on MMU && BLOCK
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106 default y
107 help
108 This option allows you to choose whether you want to have support
92c3504e 109 for so called swap devices or swap files in your kernel that are
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110 used to provide more virtual memory than the actual RAM present
111 in your computer. If unsure say Y.
112
113config SYSVIPC
114 bool "System V IPC"
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115 ---help---
116 Inter Process Communication is a suite of library functions and
117 system calls which let processes (running programs) synchronize and
118 exchange information. It is generally considered to be a good thing,
119 and some programs won't run unless you say Y here. In particular, if
120 you want to run the DOS emulator dosemu under Linux (read the
121 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
122 you'll need to say Y here.
123
124 You can find documentation about IPC with "info ipc" and also in
125 section 6.4 of the Linux Programmer's Guide, available from
126 <http://www.tldp.org/guides.html>.
127
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128config SYSVIPC_SYSCTL
129 bool
130 depends on SYSVIPC
131 depends on SYSCTL
132 default y
133
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134config POSIX_MQUEUE
135 bool "POSIX Message Queues"
136 depends on NET && EXPERIMENTAL
137 ---help---
138 POSIX variant of message queues is a part of IPC. In POSIX message
139 queues every message has a priority which decides about succession
140 of receiving it by a process. If you want to compile and run
141 programs written e.g. for Solaris with use of its POSIX message
b0e37650 142 queues (functions mq_*) say Y here.
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143
144 POSIX message queues are visible as a filesystem called 'mqueue'
145 and can be mounted somewhere if you want to do filesystem
146 operations on message queues.
147
148 If unsure, say Y.
149
150config BSD_PROCESS_ACCT
151 bool "BSD Process Accounting"
152 help
153 If you say Y here, a user level program will be able to instruct the
154 kernel (via a special system call) to write process accounting
155 information to a file: whenever a process exits, information about
156 that process will be appended to the file by the kernel. The
157 information includes things such as creation time, owning user,
158 command name, memory usage, controlling terminal etc. (the complete
159 list is in the struct acct in <file:include/linux/acct.h>). It is
160 up to the user level program to do useful things with this
161 information. This is generally a good idea, so say Y.
162
163config BSD_PROCESS_ACCT_V3
164 bool "BSD Process Accounting version 3 file format"
165 depends on BSD_PROCESS_ACCT
166 default n
167 help
168 If you say Y here, the process accounting information is written
169 in a new file format that also logs the process IDs of each
170 process and it's parent. Note that this file format is incompatible
171 with previous v0/v1/v2 file formats, so you will need updated tools
172 for processing it. A preliminary version of these tools is available
173 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
174
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175config TASKSTATS
176 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
177 depends on NET
178 default n
179 help
180 Export selected statistics for tasks/processes through the
181 generic netlink interface. Unlike BSD process accounting, the
182 statistics are available during the lifetime of tasks/processes as
183 responses to commands. Like BSD accounting, they are sent to user
184 space on task exit.
185
186 Say N if unsure.
187
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188config TASK_DELAY_ACCT
189 bool "Enable per-task delay accounting (EXPERIMENTAL)"
6f44993f 190 depends on TASKSTATS
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191 help
192 Collect information on time spent by a task waiting for system
193 resources like cpu, synchronous block I/O completion and swapping
194 in pages. Such statistics can help in setting a task's priorities
195 relative to other tasks for cpu, io, rss limits etc.
196
197 Say N if unsure.
198
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199config TASK_XACCT
200 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
201 depends on TASKSTATS
202 help
203 Collect extended task accounting data and send the data
204 to userland for processing over the taskstats interface.
205
206 Say N if unsure.
207
208config TASK_IO_ACCOUNTING
209 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
210 depends on TASK_XACCT
211 help
212 Collect information on the number of bytes of storage I/O which this
213 task has caused.
214
215 Say N if unsure.
216
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217config AUDIT
218 bool "Auditing support"
804a6a49 219 depends on NET
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220 help
221 Enable auditing infrastructure that can be used with another
222 kernel subsystem, such as SELinux (which requires this for
223 logging of avc messages output). Does not do system-call
224 auditing without CONFIG_AUDITSYSCALL.
225
226config AUDITSYSCALL
227 bool "Enable system-call auditing support"
1322b9de 228 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
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229 default y if SECURITY_SELINUX
230 help
231 Enable low-overhead system-call auditing infrastructure that
232 can be used independently or with another kernel subsystem,
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233 such as SELinux. To use audit's filesystem watch feature, please
234 ensure that INOTIFY is configured.
1da177e4 235
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236config AUDIT_TREE
237 def_bool y
238 depends on AUDITSYSCALL && INOTIFY
239
1da177e4 240config IKCONFIG
f2443ab6 241 tristate "Kernel .config support"
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242 ---help---
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).
251
252config IKCONFIG_PROC
253 bool "Enable access to .config through /proc/config.gz"
254 depends on IKCONFIG && PROC_FS
255 ---help---
256 This option enables access to the kernel configuration file
257 through /proc/config.gz.
258
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259config LOG_BUF_SHIFT
260 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
261 range 12 21
f17a32e9 262 default 17
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263 help
264 Select kernel log buffer size as a power of 2.
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265 Examples:
266 17 => 128 KB
267 16 => 64 KB
268 15 => 32 KB
269 14 => 16 KB
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270 13 => 8 KB
271 12 => 4 KB
272
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273config CGROUPS
274 bool "Control Group support"
275 help
276 This option will let you use process cgroup subsystems
277 such as Cpusets
278
279 Say N if unsure.
280
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281config CGROUP_DEBUG
282 bool "Example debug cgroup subsystem"
283 depends on CGROUPS
418d7d87 284 default n
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285 help
286 This option enables a simple cgroup subsystem that
287 exports useful debugging information about the cgroups
288 framework
289
290 Say N if unsure
291
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292config CGROUP_NS
293 bool "Namespace cgroup subsystem"
294 depends on CGROUPS
295 help
296 Provides a simple namespace cgroup subsystem to
297 provide hierarchical naming of sets of namespaces,
298 for instance virtual servers and checkpoint/restart
299 jobs.
300
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301config CGROUP_DEVICE
302 bool "Device controller for cgroups"
303 depends on CGROUPS && EXPERIMENTAL
304 help
305 Provides a cgroup implementing whitelists for devices which
306 a process in the cgroup can mknod or open.
307
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308config CPUSETS
309 bool "Cpuset support"
8793d854 310 depends on SMP && CGROUPS
1da177e4 311 help
d9fd8a6d 312 This option will let you create and manage CPUSETs which
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313 allow dynamically partitioning a system into sets of CPUs and
314 Memory Nodes and assigning tasks to run only within those sets.
315 This is primarily useful on large SMP or NUMA systems.
316
317 Say N if unsure.
318
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319config GROUP_SCHED
320 bool "Group CPU scheduler"
de8d585a 321 default y
29f59db3 322 help
fb615581 323 This feature lets CPU scheduler recognize task groups and control CPU
9b5b7751 324 bandwidth allocation to such task groups.
29f59db3 325
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326config FAIR_GROUP_SCHED
327 bool "Group scheduling for SCHED_OTHER"
328 depends on GROUP_SCHED
329 default y
330
331config RT_GROUP_SCHED
332 bool "Group scheduling for SCHED_RR/FIFO"
333 depends on EXPERIMENTAL
334 depends on GROUP_SCHED
335 default n
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336 help
337 This feature lets you explicitly allocate real CPU bandwidth
338 to users or control groups (depending on the "Basis for grouping tasks"
339 setting below. If enabled, it will also make it impossible to
340 schedule realtime tasks for non-root users until you allocate
341 realtime bandwidth for them.
342 See Documentation/sched-rt-group.txt for more information.
052f1dc7 343
24e377a8 344choice
052f1dc7 345 depends on GROUP_SCHED
24e377a8 346 prompt "Basis for grouping tasks"
052f1dc7 347 default USER_SCHED
24e377a8 348
052f1dc7 349config USER_SCHED
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350 bool "user id"
351 help
352 This option will choose userid as the basis for grouping
353 tasks, thus providing equal CPU bandwidth to each user.
24e377a8 354
052f1dc7 355config CGROUP_SCHED
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356 bool "Control groups"
357 depends on CGROUPS
358 help
359 This option allows you to create arbitrary task groups
360 using the "cgroup" pseudo filesystem and control
361 the cpu bandwidth allocated to each such task group.
362 Refer to Documentation/cgroups.txt for more information
363 on "cgroup" pseudo filesystem.
364
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365endchoice
366
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367config CGROUP_CPUACCT
368 bool "Simple CPU accounting cgroup subsystem"
369 depends on CGROUPS
370 help
371 Provides a simple Resource Controller for monitoring the
372 total CPU consumed by the tasks in a cgroup
373
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374config RESOURCE_COUNTERS
375 bool "Resource counters"
376 help
377 This option enables controller independent resource accounting
378 infrastructure that works with cgroups
379 depends on CGROUPS
380
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381config MM_OWNER
382 bool
383
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384config CGROUP_MEM_RES_CTLR
385 bool "Memory Resource Controller for Control Groups"
386 depends on CGROUPS && RESOURCE_COUNTERS
cf475ad2 387 select MM_OWNER
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388 help
389 Provides a memory resource controller that manages both page cache and
390 RSS memory.
391
392 Note that setting this option increases fixed memory overhead
393 associated with each page of memory in the system by 4/8 bytes
394 and also increases cache misses because struct page on many 64bit
395 systems will not fit into a single cache line anymore.
396
397 Only enable when you're ok with these trade offs and really
398 sure you need the memory resource controller.
399
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400 This config option also selects MM_OWNER config option, which
401 could in turn add some fork/exit overhead.
402
88a22c98 403config SYSFS_DEPRECATED
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404 bool
405
406config SYSFS_DEPRECATED_V2
88a22c98 407 bool "Create deprecated sysfs files"
9148fe87 408 depends on SYSFS
88a22c98 409 default y
d47846c5 410 select SYSFS_DEPRECATED
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411 help
412 This option creates deprecated symlinks such as the
413 "device"-link, the <subsystem>:<name>-link, and the
414 "bus"-link. It may also add deprecated key in the
415 uevent environment.
416 None of these features or values should be used today, as
417 they export driver core implementation details to userspace
418 or export properties which can't be kept stable across kernel
419 releases.
420
421 If enabled, this option will also move any device structures
3dde6ad8 422 that belong to a class, back into the /sys/class hierarchy, in
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423 order to support older versions of udev and some userspace
424 programs.
88a22c98 425
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426 If you are using a distro with the most recent userspace
427 packages, it should be safe to say N here.
88a22c98 428
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429config PROC_PID_CPUSET
430 bool "Include legacy /proc/<pid>/cpuset file"
431 depends on CPUSETS
432 default y
433
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434config RELAY
435 bool "Kernel->user space relay support (formerly relayfs)"
436 help
437 This option enables support for relay interface support in
438 certain file systems (such as debugfs).
439 It is designed to provide an efficient mechanism for tools and
440 facilities to relay large amounts of data from kernel space to
441 user space.
442
443 If unsure, say N.
444
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445config NAMESPACES
446 bool "Namespaces support" if EMBEDDED
447 default !EMBEDDED
448 help
449 Provides the way to make tasks work with different objects using
450 the same id. For example same IPC id may refer to different objects
451 or same user id or pid may refer to different tasks when used in
452 different namespaces.
453
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454config UTS_NS
455 bool "UTS namespace"
456 depends on NAMESPACES
457 help
458 In this namespace tasks see different info provided with the
459 uname() system call
460
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461config IPC_NS
462 bool "IPC namespace"
463 depends on NAMESPACES && SYSVIPC
464 help
465 In this namespace tasks work with IPC ids which correspond to
466 different IPC objects in different namespaces
467
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468config USER_NS
469 bool "User namespace (EXPERIMENTAL)"
470 depends on NAMESPACES && EXPERIMENTAL
471 help
472 This allows containers, i.e. vservers, to use user namespaces
473 to provide different user info for different servers.
474 If unsure, say N.
475
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476config PID_NS
477 bool "PID Namespaces (EXPERIMENTAL)"
478 default n
479 depends on NAMESPACES && EXPERIMENTAL
480 help
481 Suport process id namespaces. This allows having multiple
482 process with the same pid as long as they are in different
483 pid namespaces. This is a building block of containers.
484
485 Unless you want to work with an experimental feature
486 say N here.
487
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488config BLK_DEV_INITRD
489 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
490 depends on BROKEN || !FRV
491 help
492 The initial RAM filesystem is a ramfs which is loaded by the
493 boot loader (loadlin or lilo) and that is mounted as root
494 before the normal boot procedure. It is typically used to
495 load modules needed to mount the "real" root file system,
496 etc. See <file:Documentation/initrd.txt> for details.
497
498 If RAM disk support (BLK_DEV_RAM) is also included, this
499 also enables initial RAM disk (initrd) support and adds
500 15 Kbytes (more on some other architectures) to the kernel size.
501
502 If unsure say Y.
503
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504if BLK_DEV_INITRD
505
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506source "usr/Kconfig"
507
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508endif
509
c45b4f1f 510config CC_OPTIMIZE_FOR_SIZE
96fffeb4 511 bool "Optimize for size"
c45b4f1f 512 default y
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513 help
514 Enabling this option will pass "-Os" instead of "-O2" to gcc
515 resulting in a smaller kernel.
516
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517 If unsure, say N.
518
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519config SYSCTL
520 bool
521
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522menuconfig EMBEDDED
523 bool "Configure standard kernel features (for small systems)"
524 help
525 This option allows certain base kernel options and settings
526 to be disabled or tweaked. This is for specialized
527 environments which can tolerate a "non-standard" kernel.
528 Only use this if you really know what you are doing.
529
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530config UID16
531 bool "Enable 16-bit UID system calls" if EMBEDDED
09337f50 532 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
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533 default y
534 help
535 This enables the legacy 16-bit UID syscall wrappers.
536
b89a8171 537config SYSCTL_SYSCALL
0847062a 538 bool "Sysctl syscall support" if EMBEDDED
13bb7e37 539 default y
b89a8171 540 select SYSCTL
ae81f9e3 541 ---help---
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542 sys_sysctl uses binary paths that have been found challenging
543 to properly maintain and use. The interface in /proc/sys
544 using paths with ascii names is now the primary path to this
545 information.
b89a8171 546
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547 Almost nothing using the binary sysctl interface so if you are
548 trying to save some space it is probably safe to disable this,
549 making your kernel marginally smaller.
b89a8171 550
13bb7e37 551 If unsure say Y here.
ae81f9e3 552
1da177e4 553config KALLSYMS
979c6a1e 554 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
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555 default y
556 help
557 Say Y here to let the kernel print out symbolic crash information and
558 symbolic stack backtraces. This increases the size of the kernel
559 somewhat, as all symbols have to be loaded into the kernel image.
560
561config KALLSYMS_ALL
562 bool "Include all symbols in kallsyms"
563 depends on DEBUG_KERNEL && KALLSYMS
564 help
565 Normally kallsyms only contains the symbols of functions, for nicer
566 OOPS messages. Some debuggers can use kallsyms for other
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567 symbols too: say Y here to include all symbols, if you need them
568 and you don't care about adding 300k to the size of your kernel.
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569
570 Say N.
571
572config KALLSYMS_EXTRA_PASS
573 bool "Do an extra kallsyms pass"
574 depends on KALLSYMS
575 help
576 If kallsyms is not working correctly, the build will fail with
577 inconsistent kallsyms data. If that occurs, log a bug report and
578 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
579 Always say N here unless you find a bug in kallsyms, which must be
580 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
581 you wait for kallsyms to be fixed.
582
d59745ce 583
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584config HOTPLUG
585 bool "Support for hot-pluggable devices" if EMBEDDED
586 default y
587 help
588 This option is provided for the case where no hotplug or uevent
589 capabilities is wanted by the kernel. You should only consider
590 disabling this option for embedded systems that do not use modules, a
591 dynamic /dev tree, or dynamic device discovery. Just say Y.
592
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593config PRINTK
594 default y
595 bool "Enable support for printk" if EMBEDDED
596 help
597 This option enables normal printk support. Removing it
598 eliminates most of the message strings from the kernel image
599 and makes the kernel more or less silent. As this makes it
600 very difficult to diagnose system problems, saying N here is
601 strongly discouraged.
602
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603config BUG
604 bool "BUG() support" if EMBEDDED
605 default y
606 help
607 Disabling this option eliminates support for BUG and WARN, reducing
608 the size of your kernel image and potentially quietly ignoring
609 numerous fatal conditions. You should only consider disabling this
610 option for embedded systems with no facilities for reporting errors.
611 Just say Y.
612
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613config ELF_CORE
614 default y
615 bool "Enable ELF core dumps" if EMBEDDED
616 help
617 Enable support for generating core dumps. Disabling saves about 4k.
618
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619config COMPAT_BRK
620 bool "Disable heap randomization"
621 default y
622 help
623 Randomizing heap placement makes heap exploits harder, but it
624 also breaks ancient binaries (including anything libc5 based).
625 This option changes the bootup default to heap randomization
626 disabled, and can be overriden runtime by setting
627 /proc/sys/kernel/randomize_va_space to 2.
628
166124fd 629 On non-ancient distros (post-2000 ones) N is usually a safe choice.
32a93233 630
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631config BASE_FULL
632 default y
633 bool "Enable full-sized data structures for core" if EMBEDDED
634 help
635 Disabling this option reduces the size of miscellaneous core
636 kernel data structures. This saves memory on small machines,
637 but may reduce performance.
638
639config FUTEX
640 bool "Enable futex support" if EMBEDDED
641 default y
23f78d4a 642 select RT_MUTEXES
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643 help
644 Disabling this option will cause the kernel to be built without
645 support for "fast userspace mutexes". The resulting kernel may not
646 run glibc-based applications correctly.
647
5dc8bf81 648config ANON_INODES
448e3cee 649 bool
5dc8bf81 650
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651config EPOLL
652 bool "Enable eventpoll support" if EMBEDDED
653 default y
448e3cee 654 select ANON_INODES
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655 help
656 Disabling this option will cause the kernel to be built without
657 support for epoll family of system calls.
658
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659config SIGNALFD
660 bool "Enable signalfd() system call" if EMBEDDED
448e3cee 661 select ANON_INODES
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662 default y
663 help
664 Enable the signalfd() system call that allows to receive signals
665 on a file descriptor.
666
667 If unsure, say Y.
668
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669config TIMERFD
670 bool "Enable timerfd() system call" if EMBEDDED
448e3cee 671 select ANON_INODES
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672 default y
673 help
674 Enable the timerfd() system call that allows to receive timer
675 events on a file descriptor.
676
677 If unsure, say Y.
678
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679config EVENTFD
680 bool "Enable eventfd() system call" if EMBEDDED
448e3cee 681 select ANON_INODES
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682 default y
683 help
684 Enable the eventfd() system call that allows to receive both
685 kernel notification (ie. KAIO) or userspace notifications.
686
687 If unsure, say Y.
688
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689config SHMEM
690 bool "Use full shmem filesystem" if EMBEDDED
691 default y
692 depends on MMU
693 help
694 The shmem is an internal filesystem used to manage shared memory.
695 It is backed by swap and manages resource limits. It is also exported
696 to userspace as tmpfs if TMPFS is enabled. Disabling this
697 option replaces shmem and tmpfs with the much simpler ramfs code,
698 which may be appropriate on small systems without swap.
699
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700config VM_EVENT_COUNTERS
701 default y
702 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
703 help
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704 VM event counters are needed for event counts to be shown.
705 This option allows the disabling of the VM event counters
706 on EMBEDDED systems. /proc/vmstat will only show page counts
707 if VM event counters are disabled.
f8891e5e 708
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709config SLUB_DEBUG
710 default y
711 bool "Enable SLUB debugging support" if EMBEDDED
d4751a27 712 depends on SLUB
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713 help
714 SLUB has extensive debug support features. Disabling these can
715 result in significant savings in code size. This also disables
716 SLUB sysfs support. /sys/slab will not exist and there will be
717 no support for cache validation etc.
718
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719choice
720 prompt "Choose SLAB allocator"
a0acd820 721 default SLUB
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722 help
723 This option allows to select a slab allocator.
724
725config SLAB
726 bool "SLAB"
727 help
728 The regular slab allocator that is established and known to work
34013886 729 well in all environments. It organizes cache hot objects in
81819f0f 730 per cpu and per node queues. SLAB is the default choice for
34013886 731 a slab allocator.
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732
733config SLUB
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734 bool "SLUB (Unqueued Allocator)"
735 help
736 SLUB is a slab allocator that minimizes cache line usage
737 instead of managing queues of cached objects (SLAB approach).
738 Per cpu caching is realized using slabs of objects instead
739 of queues of objects. SLUB can use memory efficiently
34013886 740 and has enhanced diagnostics.
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741
742config SLOB
84a01c2f 743 depends on EMBEDDED
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744 bool "SLOB (Simple Allocator)"
745 help
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746 SLOB replaces the stock allocator with a drastically simpler
747 allocator. SLOB is generally more space efficient but
748 does not perform as well on large systems.
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749
750endchoice
751
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752config PROFILING
753 bool "Profiling support (EXPERIMENTAL)"
754 help
755 Say Y here to enable the extended profiling support mechanisms used
756 by profilers such as OProfile.
757
758config MARKERS
759 bool "Activate markers"
760 help
761 Place an empty function call at each marker site. Can be
762 dynamically changed for a probe function.
763
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764source "arch/Kconfig"
765
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766config PROC_PAGE_MONITOR
767 default y
768 depends on PROC_FS && MMU
769 bool "Enable /proc page monitoring" if EMBEDDED
770 help
771 Various /proc files exist to monitor process memory utilization:
772 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
773 /proc/kpagecount, and /proc/kpageflags. Disabling these
774 interfaces will reduce the size of the kernel by approximately 4kb.
775
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776endmenu # General setup
777
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778config SLABINFO
779 bool
780 depends on PROC_FS
0f389ec6 781 depends on SLAB || SLUB_DEBUG
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782 default y
783
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784config RT_MUTEXES
785 boolean
786 select PLIST
787
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788config TINY_SHMEM
789 default !SHMEM
790 bool
791
792config BASE_SMALL
793 int
794 default 0 if BASE_FULL
795 default 1 if !BASE_FULL
796
66da5733 797menuconfig MODULES
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798 bool "Enable loadable module support"
799 help
800 Kernel modules are small pieces of compiled code which can
801 be inserted in the running kernel, rather than being
802 permanently built into the kernel. You use the "modprobe"
803 tool to add (and sometimes remove) them. If you say Y here,
804 many parts of the kernel can be built as modules (by
805 answering M instead of Y where indicated): this is most
806 useful for infrequently used options which are not required
807 for booting. For more information, see the man pages for
808 modprobe, lsmod, modinfo, insmod and rmmod.
809
810 If you say Y here, you will need to run "make
811 modules_install" to put the modules under /lib/modules/
812 where modprobe can find them (you may need to be root to do
813 this).
814
815 If unsure, say Y.
816
817config MODULE_UNLOAD
818 bool "Module unloading"
819 depends on MODULES
820 help
821 Without this option you will not be able to unload any
822 modules (note that some modules may not be unloadable
823 anyway), which makes your kernel slightly smaller and
824 simpler. If unsure, say Y.
825
826config MODULE_FORCE_UNLOAD
827 bool "Forced module unloading"
828 depends on MODULE_UNLOAD && EXPERIMENTAL
829 help
830 This option allows you to force a module to unload, even if the
831 kernel believes it is unsafe: the kernel will remove the module
832 without waiting for anyone to stop using it (using the -f option to
833 rmmod). This is mainly for kernel developers and desperate users.
834 If unsure, say N.
835
1da177e4 836config MODVERSIONS
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837 bool "Module versioning support"
838 depends on MODULES
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839 help
840 Usually, you have to use modules compiled with your kernel.
841 Saying Y here makes it sometimes possible to use modules
842 compiled for different kernels, by adding enough information
843 to the modules to (hopefully) spot any changes which would
844 make them incompatible with the kernel you are running. If
845 unsure, say N.
846
847config MODULE_SRCVERSION_ALL
848 bool "Source checksum for all modules"
849 depends on MODULES
850 help
851 Modules which contain a MODULE_VERSION get an extra "srcversion"
852 field inserted into their modinfo section, which contains a
853 sum of the source files which made it. This helps maintainers
854 see exactly which source was used to build a module (since
855 others sometimes change the module source without updating
856 the version). With this option, such a "srcversion" field
857 will be created for all modules. If unsure, say N.
858
859config KMOD
860 bool "Automatic kernel module loading"
861 depends on MODULES
862 help
863 Normally when you have selected some parts of the kernel to
864 be created as kernel modules, you must load them (using the
865 "modprobe" command) before you can use them. If you say Y
866 here, some parts of the kernel will be able to load modules
867 automatically: when a part of the kernel needs a module, it
868 runs modprobe with the appropriate arguments, thereby
869 loading the module if it is available. If unsure, say Y.
870
871config STOP_MACHINE
872 bool
873 default y
874 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
875 help
876 Need stop_machine() primitive.
3a65dfe8 877
3a65dfe8 878source "block/Kconfig"
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879
880config PREEMPT_NOTIFIERS
881 bool
e260be67 882
e260be67 883config CLASSIC_RCU
21bbb39c 884 def_bool !PREEMPT_RCU
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885 help
886 This option selects the classic RCU implementation that is
887 designed for best read-side performance on non-realtime
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888 systems. Classic RCU is the default. Note that the
889 PREEMPT_RCU symbol is used to select/deselect this option.