fs/aio.c: make 3 functions static
[deliverable/linux.git] / init / Kconfig
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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41 drivers that have been replaced by something else, and/or are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
262 default 17 if S390 || LOCKDEP
263 default 16 if X86_NUMAQ || IA64
264 default 15 if SMP
265 default 14
266 help
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
271 15 => 32 KB for SMP
272 14 => 16 KB for uniprocessor
273 13 => 8 KB
274 12 => 4 KB
275
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276config CGROUPS
277 bool "Control Group support"
278 help
279 This option will let you use process cgroup subsystems
280 such as Cpusets
281
282 Say N if unsure.
283
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284config CGROUP_DEBUG
285 bool "Example debug cgroup subsystem"
286 depends on CGROUPS
287 help
288 This option enables a simple cgroup subsystem that
289 exports useful debugging information about the cgroups
290 framework
291
292 Say N if unsure
293
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294config CGROUP_NS
295 bool "Namespace cgroup subsystem"
296 depends on CGROUPS
297 help
298 Provides a simple namespace cgroup subsystem to
299 provide hierarchical naming of sets of namespaces,
300 for instance virtual servers and checkpoint/restart
301 jobs.
302
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303config CPUSETS
304 bool "Cpuset support"
8793d854 305 depends on SMP && CGROUPS
1da177e4 306 help
d9fd8a6d 307 This option will let you create and manage CPUSETs which
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308 allow dynamically partitioning a system into sets of CPUs and
309 Memory Nodes and assigning tasks to run only within those sets.
310 This is primarily useful on large SMP or NUMA systems.
311
312 Say N if unsure.
313
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314config GROUP_SCHED
315 bool "Group CPU scheduler"
de8d585a 316 default y
29f59db3 317 help
fb615581 318 This feature lets CPU scheduler recognize task groups and control CPU
9b5b7751 319 bandwidth allocation to such task groups.
29f59db3 320
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321config FAIR_GROUP_SCHED
322 bool "Group scheduling for SCHED_OTHER"
323 depends on GROUP_SCHED
324 default y
325
326config RT_GROUP_SCHED
327 bool "Group scheduling for SCHED_RR/FIFO"
328 depends on EXPERIMENTAL
329 depends on GROUP_SCHED
330 default n
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331 help
332 This feature lets you explicitly allocate real CPU bandwidth
333 to users or control groups (depending on the "Basis for grouping tasks"
334 setting below. If enabled, it will also make it impossible to
335 schedule realtime tasks for non-root users until you allocate
336 realtime bandwidth for them.
337 See Documentation/sched-rt-group.txt for more information.
052f1dc7 338
24e377a8 339choice
052f1dc7 340 depends on GROUP_SCHED
24e377a8 341 prompt "Basis for grouping tasks"
052f1dc7 342 default USER_SCHED
24e377a8 343
052f1dc7 344config USER_SCHED
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345 bool "user id"
346 help
347 This option will choose userid as the basis for grouping
348 tasks, thus providing equal CPU bandwidth to each user.
24e377a8 349
052f1dc7 350config CGROUP_SCHED
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351 bool "Control groups"
352 depends on CGROUPS
353 help
354 This option allows you to create arbitrary task groups
355 using the "cgroup" pseudo filesystem and control
356 the cpu bandwidth allocated to each such task group.
357 Refer to Documentation/cgroups.txt for more information
358 on "cgroup" pseudo filesystem.
359
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360endchoice
361
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362config CGROUP_CPUACCT
363 bool "Simple CPU accounting cgroup subsystem"
364 depends on CGROUPS
365 help
366 Provides a simple Resource Controller for monitoring the
367 total CPU consumed by the tasks in a cgroup
368
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369config RESOURCE_COUNTERS
370 bool "Resource counters"
371 help
372 This option enables controller independent resource accounting
373 infrastructure that works with cgroups
374 depends on CGROUPS
375
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376config CGROUP_MEM_RES_CTLR
377 bool "Memory Resource Controller for Control Groups"
378 depends on CGROUPS && RESOURCE_COUNTERS
379 help
380 Provides a memory resource controller that manages both page cache and
381 RSS memory.
382
383 Note that setting this option increases fixed memory overhead
384 associated with each page of memory in the system by 4/8 bytes
385 and also increases cache misses because struct page on many 64bit
386 systems will not fit into a single cache line anymore.
387
388 Only enable when you're ok with these trade offs and really
389 sure you need the memory resource controller.
390
88a22c98 391config SYSFS_DEPRECATED
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392 bool
393
394config SYSFS_DEPRECATED_V2
88a22c98 395 bool "Create deprecated sysfs files"
9148fe87 396 depends on SYSFS
88a22c98 397 default y
d47846c5 398 select SYSFS_DEPRECATED
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399 help
400 This option creates deprecated symlinks such as the
401 "device"-link, the <subsystem>:<name>-link, and the
402 "bus"-link. It may also add deprecated key in the
403 uevent environment.
404 None of these features or values should be used today, as
405 they export driver core implementation details to userspace
406 or export properties which can't be kept stable across kernel
407 releases.
408
409 If enabled, this option will also move any device structures
3dde6ad8 410 that belong to a class, back into the /sys/class hierarchy, in
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411 order to support older versions of udev and some userspace
412 programs.
88a22c98 413
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414 If you are using a distro with the most recent userspace
415 packages, it should be safe to say N here.
88a22c98 416
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417config PROC_PID_CPUSET
418 bool "Include legacy /proc/<pid>/cpuset file"
419 depends on CPUSETS
420 default y
421
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422config RELAY
423 bool "Kernel->user space relay support (formerly relayfs)"
424 help
425 This option enables support for relay interface support in
426 certain file systems (such as debugfs).
427 It is designed to provide an efficient mechanism for tools and
428 facilities to relay large amounts of data from kernel space to
429 user space.
430
431 If unsure, say N.
432
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433config NAMESPACES
434 bool "Namespaces support" if EMBEDDED
435 default !EMBEDDED
436 help
437 Provides the way to make tasks work with different objects using
438 the same id. For example same IPC id may refer to different objects
439 or same user id or pid may refer to different tasks when used in
440 different namespaces.
441
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442config UTS_NS
443 bool "UTS namespace"
444 depends on NAMESPACES
445 help
446 In this namespace tasks see different info provided with the
447 uname() system call
448
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449config IPC_NS
450 bool "IPC namespace"
451 depends on NAMESPACES && SYSVIPC
452 help
453 In this namespace tasks work with IPC ids which correspond to
454 different IPC objects in different namespaces
455
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456config USER_NS
457 bool "User namespace (EXPERIMENTAL)"
458 depends on NAMESPACES && EXPERIMENTAL
459 help
460 This allows containers, i.e. vservers, to use user namespaces
461 to provide different user info for different servers.
462 If unsure, say N.
463
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464config PID_NS
465 bool "PID Namespaces (EXPERIMENTAL)"
466 default n
467 depends on NAMESPACES && EXPERIMENTAL
468 help
469 Suport process id namespaces. This allows having multiple
470 process with the same pid as long as they are in different
471 pid namespaces. This is a building block of containers.
472
473 Unless you want to work with an experimental feature
474 say N here.
475
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476config BLK_DEV_INITRD
477 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
478 depends on BROKEN || !FRV
479 help
480 The initial RAM filesystem is a ramfs which is loaded by the
481 boot loader (loadlin or lilo) and that is mounted as root
482 before the normal boot procedure. It is typically used to
483 load modules needed to mount the "real" root file system,
484 etc. See <file:Documentation/initrd.txt> for details.
485
486 If RAM disk support (BLK_DEV_RAM) is also included, this
487 also enables initial RAM disk (initrd) support and adds
488 15 Kbytes (more on some other architectures) to the kernel size.
489
490 If unsure say Y.
491
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492if BLK_DEV_INITRD
493
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494source "usr/Kconfig"
495
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496endif
497
c45b4f1f 498config CC_OPTIMIZE_FOR_SIZE
96fffeb4 499 bool "Optimize for size"
c45b4f1f 500 default y
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501 help
502 Enabling this option will pass "-Os" instead of "-O2" to gcc
503 resulting in a smaller kernel.
504
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505 If unsure, say N.
506
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507config SYSCTL
508 bool
509
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510menuconfig EMBEDDED
511 bool "Configure standard kernel features (for small systems)"
512 help
513 This option allows certain base kernel options and settings
514 to be disabled or tweaked. This is for specialized
515 environments which can tolerate a "non-standard" kernel.
516 Only use this if you really know what you are doing.
517
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518config UID16
519 bool "Enable 16-bit UID system calls" if EMBEDDED
09337f50 520 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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521 default y
522 help
523 This enables the legacy 16-bit UID syscall wrappers.
524
b89a8171 525config SYSCTL_SYSCALL
0847062a 526 bool "Sysctl syscall support" if EMBEDDED
13bb7e37 527 default y
b89a8171 528 select SYSCTL
ae81f9e3 529 ---help---
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530 sys_sysctl uses binary paths that have been found challenging
531 to properly maintain and use. The interface in /proc/sys
532 using paths with ascii names is now the primary path to this
533 information.
b89a8171 534
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535 Almost nothing using the binary sysctl interface so if you are
536 trying to save some space it is probably safe to disable this,
537 making your kernel marginally smaller.
b89a8171 538
13bb7e37 539 If unsure say Y here.
ae81f9e3 540
1da177e4 541config KALLSYMS
979c6a1e 542 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
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543 default y
544 help
545 Say Y here to let the kernel print out symbolic crash information and
546 symbolic stack backtraces. This increases the size of the kernel
547 somewhat, as all symbols have to be loaded into the kernel image.
548
549config KALLSYMS_ALL
550 bool "Include all symbols in kallsyms"
551 depends on DEBUG_KERNEL && KALLSYMS
552 help
553 Normally kallsyms only contains the symbols of functions, for nicer
554 OOPS messages. Some debuggers can use kallsyms for other
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555 symbols too: say Y here to include all symbols, if you need them
556 and you don't care about adding 300k to the size of your kernel.
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557
558 Say N.
559
560config KALLSYMS_EXTRA_PASS
561 bool "Do an extra kallsyms pass"
562 depends on KALLSYMS
563 help
564 If kallsyms is not working correctly, the build will fail with
565 inconsistent kallsyms data. If that occurs, log a bug report and
566 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
567 Always say N here unless you find a bug in kallsyms, which must be
568 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
569 you wait for kallsyms to be fixed.
570
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572config HOTPLUG
573 bool "Support for hot-pluggable devices" if EMBEDDED
574 default y
575 help
576 This option is provided for the case where no hotplug or uevent
577 capabilities is wanted by the kernel. You should only consider
578 disabling this option for embedded systems that do not use modules, a
579 dynamic /dev tree, or dynamic device discovery. Just say Y.
580
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581config PRINTK
582 default y
583 bool "Enable support for printk" if EMBEDDED
584 help
585 This option enables normal printk support. Removing it
586 eliminates most of the message strings from the kernel image
587 and makes the kernel more or less silent. As this makes it
588 very difficult to diagnose system problems, saying N here is
589 strongly discouraged.
590
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591config BUG
592 bool "BUG() support" if EMBEDDED
593 default y
594 help
595 Disabling this option eliminates support for BUG and WARN, reducing
596 the size of your kernel image and potentially quietly ignoring
597 numerous fatal conditions. You should only consider disabling this
598 option for embedded systems with no facilities for reporting errors.
599 Just say Y.
600
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601config ELF_CORE
602 default y
603 bool "Enable ELF core dumps" if EMBEDDED
604 help
605 Enable support for generating core dumps. Disabling saves about 4k.
606
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607config COMPAT_BRK
608 bool "Disable heap randomization"
609 default y
610 help
611 Randomizing heap placement makes heap exploits harder, but it
612 also breaks ancient binaries (including anything libc5 based).
613 This option changes the bootup default to heap randomization
614 disabled, and can be overriden runtime by setting
615 /proc/sys/kernel/randomize_va_space to 2.
616
166124fd 617 On non-ancient distros (post-2000 ones) N is usually a safe choice.
32a93233 618
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619config BASE_FULL
620 default y
621 bool "Enable full-sized data structures for core" if EMBEDDED
622 help
623 Disabling this option reduces the size of miscellaneous core
624 kernel data structures. This saves memory on small machines,
625 but may reduce performance.
626
627config FUTEX
628 bool "Enable futex support" if EMBEDDED
629 default y
23f78d4a 630 select RT_MUTEXES
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631 help
632 Disabling this option will cause the kernel to be built without
633 support for "fast userspace mutexes". The resulting kernel may not
634 run glibc-based applications correctly.
635
5dc8bf81 636config ANON_INODES
448e3cee 637 bool
5dc8bf81 638
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639config EPOLL
640 bool "Enable eventpoll support" if EMBEDDED
641 default y
448e3cee 642 select ANON_INODES
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643 help
644 Disabling this option will cause the kernel to be built without
645 support for epoll family of system calls.
646
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647config SIGNALFD
648 bool "Enable signalfd() system call" if EMBEDDED
448e3cee 649 select ANON_INODES
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650 default y
651 help
652 Enable the signalfd() system call that allows to receive signals
653 on a file descriptor.
654
655 If unsure, say Y.
656
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657config TIMERFD
658 bool "Enable timerfd() system call" if EMBEDDED
448e3cee 659 select ANON_INODES
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660 default y
661 help
662 Enable the timerfd() system call that allows to receive timer
663 events on a file descriptor.
664
665 If unsure, say Y.
666
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667config EVENTFD
668 bool "Enable eventfd() system call" if EMBEDDED
448e3cee 669 select ANON_INODES
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670 default y
671 help
672 Enable the eventfd() system call that allows to receive both
673 kernel notification (ie. KAIO) or userspace notifications.
674
675 If unsure, say Y.
676
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677config SHMEM
678 bool "Use full shmem filesystem" if EMBEDDED
679 default y
680 depends on MMU
681 help
682 The shmem is an internal filesystem used to manage shared memory.
683 It is backed by swap and manages resource limits. It is also exported
684 to userspace as tmpfs if TMPFS is enabled. Disabling this
685 option replaces shmem and tmpfs with the much simpler ramfs code,
686 which may be appropriate on small systems without swap.
687
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688config VM_EVENT_COUNTERS
689 default y
690 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
691 help
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692 VM event counters are needed for event counts to be shown.
693 This option allows the disabling of the VM event counters
694 on EMBEDDED systems. /proc/vmstat will only show page counts
695 if VM event counters are disabled.
f8891e5e 696
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697config SLUB_DEBUG
698 default y
699 bool "Enable SLUB debugging support" if EMBEDDED
d4751a27 700 depends on SLUB
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701 help
702 SLUB has extensive debug support features. Disabling these can
703 result in significant savings in code size. This also disables
704 SLUB sysfs support. /sys/slab will not exist and there will be
705 no support for cache validation etc.
706
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707choice
708 prompt "Choose SLAB allocator"
a0acd820 709 default SLUB
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710 help
711 This option allows to select a slab allocator.
712
713config SLAB
714 bool "SLAB"
715 help
716 The regular slab allocator that is established and known to work
34013886 717 well in all environments. It organizes cache hot objects in
81819f0f 718 per cpu and per node queues. SLAB is the default choice for
34013886 719 a slab allocator.
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720
721config SLUB
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722 bool "SLUB (Unqueued Allocator)"
723 help
724 SLUB is a slab allocator that minimizes cache line usage
725 instead of managing queues of cached objects (SLAB approach).
726 Per cpu caching is realized using slabs of objects instead
727 of queues of objects. SLUB can use memory efficiently
34013886 728 and has enhanced diagnostics.
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729
730config SLOB
84a01c2f 731 depends on EMBEDDED
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732 bool "SLOB (Simple Allocator)"
733 help
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734 SLOB replaces the stock allocator with a drastically simpler
735 allocator. SLOB is generally more space efficient but
736 does not perform as well on large systems.
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737
738endchoice
739
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740config PROFILING
741 bool "Profiling support (EXPERIMENTAL)"
742 help
743 Say Y here to enable the extended profiling support mechanisms used
744 by profilers such as OProfile.
745
746config MARKERS
747 bool "Activate markers"
748 help
749 Place an empty function call at each marker site. Can be
750 dynamically changed for a probe function.
751
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752source "arch/Kconfig"
753
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754config PROC_PAGE_MONITOR
755 default y
756 depends on PROC_FS && MMU
757 bool "Enable /proc page monitoring" if EMBEDDED
758 help
759 Various /proc files exist to monitor process memory utilization:
760 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
761 /proc/kpagecount, and /proc/kpageflags. Disabling these
762 interfaces will reduce the size of the kernel by approximately 4kb.
763
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764endmenu # General setup
765
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766config SLABINFO
767 bool
768 depends on PROC_FS
0f389ec6 769 depends on SLAB || SLUB_DEBUG
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770 default y
771
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772config RT_MUTEXES
773 boolean
774 select PLIST
775
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776config TINY_SHMEM
777 default !SHMEM
778 bool
779
780config BASE_SMALL
781 int
782 default 0 if BASE_FULL
783 default 1 if !BASE_FULL
784
66da5733 785menuconfig MODULES
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786 bool "Enable loadable module support"
787 help
788 Kernel modules are small pieces of compiled code which can
789 be inserted in the running kernel, rather than being
790 permanently built into the kernel. You use the "modprobe"
791 tool to add (and sometimes remove) them. If you say Y here,
792 many parts of the kernel can be built as modules (by
793 answering M instead of Y where indicated): this is most
794 useful for infrequently used options which are not required
795 for booting. For more information, see the man pages for
796 modprobe, lsmod, modinfo, insmod and rmmod.
797
798 If you say Y here, you will need to run "make
799 modules_install" to put the modules under /lib/modules/
800 where modprobe can find them (you may need to be root to do
801 this).
802
803 If unsure, say Y.
804
805config MODULE_UNLOAD
806 bool "Module unloading"
807 depends on MODULES
808 help
809 Without this option you will not be able to unload any
810 modules (note that some modules may not be unloadable
811 anyway), which makes your kernel slightly smaller and
812 simpler. If unsure, say Y.
813
814config MODULE_FORCE_UNLOAD
815 bool "Forced module unloading"
816 depends on MODULE_UNLOAD && EXPERIMENTAL
817 help
818 This option allows you to force a module to unload, even if the
819 kernel believes it is unsafe: the kernel will remove the module
820 without waiting for anyone to stop using it (using the -f option to
821 rmmod). This is mainly for kernel developers and desperate users.
822 If unsure, say N.
823
1da177e4 824config MODVERSIONS
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825 bool "Module versioning support"
826 depends on MODULES
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827 help
828 Usually, you have to use modules compiled with your kernel.
829 Saying Y here makes it sometimes possible to use modules
830 compiled for different kernels, by adding enough information
831 to the modules to (hopefully) spot any changes which would
832 make them incompatible with the kernel you are running. If
833 unsure, say N.
834
835config MODULE_SRCVERSION_ALL
836 bool "Source checksum for all modules"
837 depends on MODULES
838 help
839 Modules which contain a MODULE_VERSION get an extra "srcversion"
840 field inserted into their modinfo section, which contains a
841 sum of the source files which made it. This helps maintainers
842 see exactly which source was used to build a module (since
843 others sometimes change the module source without updating
844 the version). With this option, such a "srcversion" field
845 will be created for all modules. If unsure, say N.
846
847config KMOD
848 bool "Automatic kernel module loading"
849 depends on MODULES
850 help
851 Normally when you have selected some parts of the kernel to
852 be created as kernel modules, you must load them (using the
853 "modprobe" command) before you can use them. If you say Y
854 here, some parts of the kernel will be able to load modules
855 automatically: when a part of the kernel needs a module, it
856 runs modprobe with the appropriate arguments, thereby
857 loading the module if it is available. If unsure, say Y.
858
859config STOP_MACHINE
860 bool
861 default y
862 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
863 help
864 Need stop_machine() primitive.
3a65dfe8 865
3a65dfe8 866source "block/Kconfig"
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867
868config PREEMPT_NOTIFIERS
869 bool
e260be67 870
e260be67 871config CLASSIC_RCU
21bbb39c 872 def_bool !PREEMPT_RCU
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873 help
874 This option selects the classic RCU implementation that is
875 designed for best read-side performance on non-realtime
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876 systems. Classic RCU is the default. Note that the
877 PREEMPT_RCU symbol is used to select/deselect this option.
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