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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Al Boldiff0cfc62007-07-31 00:39:23 -070019menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21config EXPERIMENTAL
22 bool "Prompt for development and/or incomplete code/drivers"
23 ---help---
24 Some of the various things that Linux supports (such as network
25 drivers, file systems, network protocols, etc.) can be in a state
26 of development where the functionality, stability, or the level of
27 testing is not yet high enough for general use. This is usually
28 known as the "alpha-test" phase among developers. If a feature is
29 currently in alpha-test, then the developers usually discourage
30 uninformed widespread use of this feature by the general public to
31 avoid "Why doesn't this work?" type mail messages. However, active
32 testing and use of these systems is welcomed. Just be aware that it
33 may not meet the normal level of reliability or it may fail to work
34 in some special cases. Detailed bug reports from people familiar
35 with the kernel internals are usually welcomed by the developers
36 (before submitting bug reports, please read the documents
37 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
38 <file:Documentation/BUG-HUNTING>, and
39 <file:Documentation/oops-tracing.txt> in the kernel source).
40
41 This option will also make obsoleted drivers available. These are
42 drivers that have been replaced by something else, and/or are
43 scheduled to be removed in a future kernel release.
44
45 Unless you intend to help test and develop a feature or driver that
46 falls into this category, or you have a situation that requires
47 using these features, you should probably say N here, which will
48 cause the configurator to present you with fewer choices. If
49 you say Y here, you will be offered the choice of using features or
50 drivers that are currently considered to be in the alpha-test phase.
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052config BROKEN
53 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55config BROKEN_ON_SMP
56 bool
57 depends on BROKEN || !SMP
58 default y
59
60config LOCK_KERNEL
61 bool
62 depends on SMP || PREEMPT
63 default y
64
65config INIT_ENV_ARG_LIMIT
66 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070067 default 32 if !UML
68 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080070 Maximum of each of the number of arguments and environment
71 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74config LOCALVERSION
75 string "Local version - append to kernel release"
76 help
77 Append an extra string to the end of your kernel version.
78 This will show up when you type uname, for example.
79 The string you set here will be appended after the contents of
80 any files with a filename matching localversion* in your
81 object and source tree, in that order. Your total string can
82 be a maximum of 64 characters.
83
Ryan Andersonaaebf432005-07-31 04:57:49 -040084config LOCALVERSION_AUTO
85 bool "Automatically append version information to the version string"
86 default y
87 help
88 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 release tree by looking for git tags that belong to the current
90 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040091
92 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040094 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020095 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040096
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020097 (The actual string used here is the first eight characters produced
98 by running the command:
99
100 $ git rev-parse --verify HEAD
101
102 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400103
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800104config HAVE_KERNEL_GZIP
105 bool
106
107config HAVE_KERNEL_BZIP2
108 bool
109
110config HAVE_KERNEL_LZMA
111 bool
112
Alain Knaff30d65db2009-01-04 22:46:17 +0100113choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800114 prompt "Kernel compression mode"
115 default KERNEL_GZIP
116 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
117 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100118 The linux kernel is a kind of self-extracting executable.
119 Several compression algorithms are available, which differ
120 in efficiency, compression and decompression speed.
121 Compression speed is only relevant when building a kernel.
122 Decompression speed is relevant at each boot.
123
124 If you have any problems with bzip2 or lzma compressed
125 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
126 version of this functionality (bzip2 only), for 2.4, was
127 supplied by Christian Ludwig)
128
129 High compression options are mostly useful for users, who
130 are low on disk space (embedded systems), but for whom ram
131 size matters less.
132
133 If in doubt, select 'gzip'
134
135config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800136 bool "Gzip"
137 depends on HAVE_KERNEL_GZIP
138 help
139 The old and tried gzip compression. Its compression ratio is
140 the poorest among the 3 choices; however its speed (both
141 compression and decompression) is the fastest.
Alain Knaff30d65db2009-01-04 22:46:17 +0100142
143config KERNEL_BZIP2
144 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800145 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100146 help
147 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800148 Decompression speed is slowest among the three. The kernel
149 size is about 10% smaller with bzip2, in comparison to gzip.
150 Bzip2 uses a large amount of memory. For modern kernels you
151 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100152
153config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800154 bool "LZMA"
155 depends on HAVE_KERNEL_LZMA
156 help
157 The most recent compression algorithm.
158 Its ratio is best, decompression speed is between the other
159 two. Compression is slowest. The kernel size is about 33%
160 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
162endchoice
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164config SWAP
165 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200166 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 default y
168 help
169 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100170 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 used to provide more virtual memory than the actual RAM present
172 in your computer. If unsure say Y.
173
174config SYSVIPC
175 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 ---help---
177 Inter Process Communication is a suite of library functions and
178 system calls which let processes (running programs) synchronize and
179 exchange information. It is generally considered to be a good thing,
180 and some programs won't run unless you say Y here. In particular, if
181 you want to run the DOS emulator dosemu under Linux (read the
182 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
183 you'll need to say Y here.
184
185 You can find documentation about IPC with "info ipc" and also in
186 section 6.4 of the Linux Programmer's Guide, available from
187 <http://www.tldp.org/guides.html>.
188
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800189config SYSVIPC_SYSCTL
190 bool
191 depends on SYSVIPC
192 depends on SYSCTL
193 default y
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195config POSIX_MQUEUE
196 bool "POSIX Message Queues"
197 depends on NET && EXPERIMENTAL
198 ---help---
199 POSIX variant of message queues is a part of IPC. In POSIX message
200 queues every message has a priority which decides about succession
201 of receiving it by a process. If you want to compile and run
202 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200203 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205 POSIX message queues are visible as a filesystem called 'mqueue'
206 and can be mounted somewhere if you want to do filesystem
207 operations on message queues.
208
209 If unsure, say Y.
210
211config BSD_PROCESS_ACCT
212 bool "BSD Process Accounting"
213 help
214 If you say Y here, a user level program will be able to instruct the
215 kernel (via a special system call) to write process accounting
216 information to a file: whenever a process exits, information about
217 that process will be appended to the file by the kernel. The
218 information includes things such as creation time, owning user,
219 command name, memory usage, controlling terminal etc. (the complete
220 list is in the struct acct in <file:include/linux/acct.h>). It is
221 up to the user level program to do useful things with this
222 information. This is generally a good idea, so say Y.
223
224config BSD_PROCESS_ACCT_V3
225 bool "BSD Process Accounting version 3 file format"
226 depends on BSD_PROCESS_ACCT
227 default n
228 help
229 If you say Y here, the process accounting information is written
230 in a new file format that also logs the process IDs of each
231 process and it's parent. Note that this file format is incompatible
232 with previous v0/v1/v2 file formats, so you will need updated tools
233 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300234 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Shailabh Nagarc7572492006-07-14 00:24:40 -0700236config TASKSTATS
237 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
238 depends on NET
239 default n
240 help
241 Export selected statistics for tasks/processes through the
242 generic netlink interface. Unlike BSD process accounting, the
243 statistics are available during the lifetime of tasks/processes as
244 responses to commands. Like BSD accounting, they are sent to user
245 space on task exit.
246
247 Say N if unsure.
248
Shailabh Nagarca74e922006-07-14 00:24:36 -0700249config TASK_DELAY_ACCT
250 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700251 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700252 help
253 Collect information on time spent by a task waiting for system
254 resources like cpu, synchronous block I/O completion and swapping
255 in pages. Such statistics can help in setting a task's priorities
256 relative to other tasks for cpu, io, rss limits etc.
257
258 Say N if unsure.
259
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800260config TASK_XACCT
261 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
262 depends on TASKSTATS
263 help
264 Collect extended task accounting data and send the data
265 to userland for processing over the taskstats interface.
266
267 Say N if unsure.
268
269config TASK_IO_ACCOUNTING
270 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
271 depends on TASK_XACCT
272 help
273 Collect information on the number of bytes of storage I/O which this
274 task has caused.
275
276 Say N if unsure.
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278config AUDIT
279 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100280 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 help
282 Enable auditing infrastructure that can be used with another
283 kernel subsystem, such as SELinux (which requires this for
284 logging of avc messages output). Does not do system-call
285 auditing without CONFIG_AUDITSYSCALL.
286
287config AUDITSYSCALL
288 bool "Enable system-call auditing support"
Yuichi Nakamura1322b9d2007-11-10 19:21:34 +0900289 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 default y if SECURITY_SELINUX
291 help
292 Enable low-overhead system-call auditing infrastructure that
293 can be used independently or with another kernel subsystem,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400294 such as SELinux. To use audit's filesystem watch feature, please
295 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Al Viro74c3cbe2007-07-22 08:04:18 -0400297config AUDIT_TREE
298 def_bool y
299 depends on AUDITSYSCALL && INOTIFY
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700302 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 ---help---
304 This option enables the complete Linux kernel ".config" file
305 contents to be saved in the kernel. It provides documentation
306 of which kernel options are used in a running kernel or in an
307 on-disk kernel. This information can be extracted from the kernel
308 image file with the script scripts/extract-ikconfig and used as
309 input to rebuild the current kernel or to build another kernel.
310 It can also be extracted from a running kernel by reading
311 /proc/config.gz if enabled (below).
312
313config IKCONFIG_PROC
314 bool "Enable access to .config through /proc/config.gz"
315 depends on IKCONFIG && PROC_FS
316 ---help---
317 This option enables access to the kernel configuration file
318 through /proc/config.gz.
319
Alistair John Strachan794543a2007-05-08 00:31:15 -0700320config LOG_BUF_SHIFT
321 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
322 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700323 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700324 help
325 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700326 Examples:
327 17 => 128 KB
328 16 => 64 KB
329 15 => 32 KB
330 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700331 13 => 8 KB
332 12 => 4 KB
333
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800334#
335# Architectures with an unreliable sched_clock() should select this:
336#
337config HAVE_UNSTABLE_SCHED_CLOCK
338 bool
339
340config GROUP_SCHED
341 bool "Group CPU scheduler"
342 depends on EXPERIMENTAL
343 default n
344 help
345 This feature lets CPU scheduler recognize task groups and control CPU
346 bandwidth allocation to such task groups.
347 In order to create a group from arbitrary set of processes, use
348 CONFIG_CGROUPS. (See Control Group support.)
349
350config FAIR_GROUP_SCHED
351 bool "Group scheduling for SCHED_OTHER"
352 depends on GROUP_SCHED
353 default GROUP_SCHED
354
355config RT_GROUP_SCHED
356 bool "Group scheduling for SCHED_RR/FIFO"
357 depends on EXPERIMENTAL
358 depends on GROUP_SCHED
359 default n
360 help
361 This feature lets you explicitly allocate real CPU bandwidth
362 to users or control groups (depending on the "Basis for grouping tasks"
363 setting below. If enabled, it will also make it impossible to
364 schedule realtime tasks for non-root users until you allocate
365 realtime bandwidth for them.
366 See Documentation/scheduler/sched-rt-group.txt for more information.
367
368choice
369 depends on GROUP_SCHED
370 prompt "Basis for grouping tasks"
371 default USER_SCHED
372
373config USER_SCHED
374 bool "user id"
375 help
376 This option will choose userid as the basis for grouping
377 tasks, thus providing equal CPU bandwidth to each user.
378
379config CGROUP_SCHED
380 bool "Control groups"
381 depends on CGROUPS
382 help
383 This option allows you to create arbitrary task groups
384 using the "cgroup" pseudo filesystem and control
385 the cpu bandwidth allocated to each such task group.
386 Refer to Documentation/cgroups.txt for more information
387 on "cgroup" pseudo filesystem.
388
389endchoice
390
391menu "Control Group support"
Paul Menageddbcc7e2007-10-18 23:39:30 -0700392config CGROUPS
393 bool "Control Group support"
394 help
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800395 This option add support for grouping sets of processes together, for
396 use with process control subsystems such as Cpusets, CFS, memory
397 controls or device isolation.
398 See
399 - Documentation/cpusets.txt (Cpusets)
400 - Documentation/scheduler/sched-design-CFS.txt (CFS)
401 - Documentation/cgroups/ (features for grouping, isolation)
402 - Documentation/controllers/ (features for resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700403
404 Say N if unsure.
405
Paul Menage006cb992007-10-18 23:39:43 -0700406config CGROUP_DEBUG
407 bool "Example debug cgroup subsystem"
408 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700409 default n
Paul Menage006cb992007-10-18 23:39:43 -0700410 help
411 This option enables a simple cgroup subsystem that
412 exports useful debugging information about the cgroups
413 framework
414
415 Say N if unsure
416
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700417config CGROUP_NS
418 bool "Namespace cgroup subsystem"
419 depends on CGROUPS
420 help
421 Provides a simple namespace cgroup subsystem to
422 provide hierarchical naming of sets of namespaces,
423 for instance virtual servers and checkpoint/restart
424 jobs.
425
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700426config CGROUP_FREEZER
427 bool "control group freezer subsystem"
428 depends on CGROUPS
429 help
430 Provides a way to freeze and unfreeze all tasks in a
431 cgroup.
432
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700433config CGROUP_DEVICE
434 bool "Device controller for cgroups"
435 depends on CGROUPS && EXPERIMENTAL
436 help
437 Provides a cgroup implementing whitelists for devices which
438 a process in the cgroup can mknod or open.
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440config CPUSETS
441 bool "Cpuset support"
Paul Menage8793d852007-10-18 23:39:39 -0700442 depends on SMP && CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700444 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 allow dynamically partitioning a system into sets of CPUs and
446 Memory Nodes and assigning tasks to run only within those sets.
447 This is primarily useful on large SMP or NUMA systems.
448
449 Say N if unsure.
450
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100451config CGROUP_CPUACCT
452 bool "Simple CPU accounting cgroup subsystem"
453 depends on CGROUPS
454 help
455 Provides a simple Resource Controller for monitoring the
456 total CPU consumed by the tasks in a cgroup
457
Pavel Emelianove552b662008-02-07 00:13:49 -0800458config RESOURCE_COUNTERS
459 bool "Resource counters"
460 help
461 This option enables controller independent resource accounting
462 infrastructure that works with cgroups
463 depends on CGROUPS
464
Balbir Singh00f0b822008-03-04 14:28:39 -0800465config CGROUP_MEM_RES_CTLR
466 bool "Memory Resource Controller for Control Groups"
467 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700468 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800469 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700470 Provides a memory resource controller that manages both anonymous
471 memory and page cache. (See Documentation/controllers/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800472
473 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700474 associated with each page of memory in the system. By this,
475 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
476 usage tracking struct at boot. Total amount of this is printed out
477 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800478
479 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700480 sure you need the memory resource controller. Even when you enable
481 this, you can set "cgroup_disable=memory" at your boot option to
482 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800483 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800484
Balbir Singhcf475ad2008-04-29 01:00:16 -0700485 This config option also selects MM_OWNER config option, which
486 could in turn add some fork/exit overhead.
487
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800488config MM_OWNER
489 bool
490
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800491config CGROUP_MEM_RES_CTLR_SWAP
492 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
493 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
494 help
495 Add swap management feature to memory resource controller. When you
496 enable this, you can limit mem+swap usage per cgroup. In other words,
497 when you disable this, memory resource controller has no cares to
498 usage of swap...a process can exhaust all of the swap. This extension
499 is useful when you want to avoid exhaustion swap but this itself
500 adds more overheads and consumes memory for remembering information.
501 Especially if you use 32bit system or small memory system, please
502 be careful about enabling this. When memory resource controller
503 is disabled by boot option, this will be automatically disabled and
504 there will be no overhead from this. Even when you set this config=y,
505 if boot option "noswapaccount" is set, swap will not be accounted.
506
507
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800508endmenu
509
Kay Sievers88a22c92006-09-14 11:23:28 +0200510config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100511 bool
512
513config SYSFS_DEPRECATED_V2
Kay Sieversfce3e802008-11-01 14:03:00 +0100514 bool "Create deprecated sysfs layout for older userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800515 depends on SYSFS
Kay Sievers88a22c92006-09-14 11:23:28 +0200516 default y
Ingo Molnard47846c2008-03-04 14:54:47 +0100517 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200518 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100519 This option switches the layout of sysfs to the deprecated
520 version.
Kay Sievers88a22c92006-09-14 11:23:28 +0200521
Kay Sieversfce3e802008-11-01 14:03:00 +0100522 The current sysfs layout features a unified device tree at
523 /sys/devices/, which is able to express a hierarchy between
524 class devices. If the deprecated option is set to Y, the
525 unified device tree is split into a bus device tree at
526 /sys/devices/ and several individual class device trees at
527 /sys/class/. The class and bus devices will be connected by
528 "<subsystem>:<name>" and the "device" links. The "block"
529 class devices, will not show up in /sys/class/block/. Some
530 subsystems will suppress the creation of some devices which
531 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200532
Kay Sieversfce3e802008-11-01 14:03:00 +0100533 This option is not a pure compatibility option that can
534 be safely enabled on newer distributions. It will change the
535 layout of sysfs to the non-extensible deprecated version,
536 and disable some features, which can not be exported without
537 confusing older userspace tools. Since 2007/2008 all major
538 distributions do not enable this option, and ship no tools which
539 depend on the deprecated layout or this option.
540
541 If you are using a new kernel on an older distribution, or use
542 older userspace tools, you might need to say Y here. Do not say Y,
543 if the original kernel, that came with your distribution, has
544 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200545
Paul Menage8793d852007-10-18 23:39:39 -0700546config PROC_PID_CPUSET
547 bool "Include legacy /proc/<pid>/cpuset file"
548 depends on CPUSETS
549 default y
550
Jens Axboeb86ff9812006-03-23 19:56:55 +0100551config RELAY
552 bool "Kernel->user space relay support (formerly relayfs)"
553 help
554 This option enables support for relay interface support in
555 certain file systems (such as debugfs).
556 It is designed to provide an efficient mechanism for tools and
557 facilities to relay large amounts of data from kernel space to
558 user space.
559
560 If unsure, say N.
561
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800562config NAMESPACES
563 bool "Namespaces support" if EMBEDDED
564 default !EMBEDDED
565 help
566 Provides the way to make tasks work with different objects using
567 the same id. For example same IPC id may refer to different objects
568 or same user id or pid may refer to different tasks when used in
569 different namespaces.
570
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800571config UTS_NS
572 bool "UTS namespace"
573 depends on NAMESPACES
574 help
575 In this namespace tasks see different info provided with the
576 uname() system call
577
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800578config IPC_NS
579 bool "IPC namespace"
580 depends on NAMESPACES && SYSVIPC
581 help
582 In this namespace tasks work with IPC ids which correspond to
583 different IPC objects in different namespaces
584
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800585config USER_NS
586 bool "User namespace (EXPERIMENTAL)"
587 depends on NAMESPACES && EXPERIMENTAL
588 help
589 This allows containers, i.e. vservers, to use user namespaces
590 to provide different user info for different servers.
591 If unsure, say N.
592
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800593config PID_NS
594 bool "PID Namespaces (EXPERIMENTAL)"
595 default n
596 depends on NAMESPACES && EXPERIMENTAL
597 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300598 Support process id namespaces. This allows having multiple
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800599 process with the same pid as long as they are in different
600 pid namespaces. This is a building block of containers.
601
602 Unless you want to work with an experimental feature
603 say N here.
604
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800605config BLK_DEV_INITRD
606 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
607 depends on BROKEN || !FRV
608 help
609 The initial RAM filesystem is a ramfs which is loaded by the
610 boot loader (loadlin or lilo) and that is mounted as root
611 before the normal boot procedure. It is typically used to
612 load modules needed to mount the "real" root file system,
613 etc. See <file:Documentation/initrd.txt> for details.
614
615 If RAM disk support (BLK_DEV_RAM) is also included, this
616 also enables initial RAM disk (initrd) support and adds
617 15 Kbytes (more on some other architectures) to the kernel size.
618
619 If unsure say Y.
620
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800621if BLK_DEV_INITRD
622
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200623source "usr/Kconfig"
624
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800625endif
626
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800627config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200628 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800629 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800630 help
631 Enabling this option will pass "-Os" instead of "-O2" to gcc
632 resulting in a smaller kernel.
633
jkacur775a7222008-07-16 00:31:16 +0200634 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800635
Randy Dunlap08470622006-09-30 23:28:13 -0700636config SYSCTL
637 bool
638
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639menuconfig EMBEDDED
640 bool "Configure standard kernel features (for small systems)"
641 help
642 This option allows certain base kernel options and settings
643 to be disabled or tweaked. This is for specialized
644 environments which can tolerate a "non-standard" kernel.
645 Only use this if you really know what you are doing.
646
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700647config UID16
648 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700649 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700650 default y
651 help
652 This enables the legacy 16-bit UID syscall wrappers.
653
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700654config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700655 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800656 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700657 select SYSCTL
658 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800659 sys_sysctl uses binary paths that have been found challenging
660 to properly maintain and use. The interface in /proc/sys
661 using paths with ascii names is now the primary path to this
662 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700663
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800664 Almost nothing using the binary sysctl interface so if you are
665 trying to save some space it is probably safe to disable this,
666 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700667
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800668 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100671 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 default y
673 help
674 Say Y here to let the kernel print out symbolic crash information and
675 symbolic stack backtraces. This increases the size of the kernel
676 somewhat, as all symbols have to be loaded into the kernel image.
677
678config KALLSYMS_ALL
679 bool "Include all symbols in kallsyms"
680 depends on DEBUG_KERNEL && KALLSYMS
681 help
682 Normally kallsyms only contains the symbols of functions, for nicer
683 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200684 symbols too: say Y here to include all symbols, if you need them
685 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686
687 Say N.
688
Jan Beulich9bb48242008-12-16 11:30:08 +0000689config KALLSYMS_STRIP_GENERATED
690 bool "Strip machine generated symbols from kallsyms"
691 depends on KALLSYMS_ALL
692 default y
693 help
694 Say N if you want kallsyms to retain even machine generated symbols.
695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696config KALLSYMS_EXTRA_PASS
697 bool "Do an extra kallsyms pass"
698 depends on KALLSYMS
699 help
700 If kallsyms is not working correctly, the build will fail with
701 inconsistent kallsyms data. If that occurs, log a bug report and
702 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
703 Always say N here unless you find a bug in kallsyms, which must be
704 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
705 you wait for kallsyms to be fixed.
706
Matt Mackalld59745c2005-05-01 08:59:02 -0700707
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800708config HOTPLUG
709 bool "Support for hot-pluggable devices" if EMBEDDED
710 default y
711 help
712 This option is provided for the case where no hotplug or uevent
713 capabilities is wanted by the kernel. You should only consider
714 disabling this option for embedded systems that do not use modules, a
715 dynamic /dev tree, or dynamic device discovery. Just say Y.
716
Matt Mackalld59745c2005-05-01 08:59:02 -0700717config PRINTK
718 default y
719 bool "Enable support for printk" if EMBEDDED
720 help
721 This option enables normal printk support. Removing it
722 eliminates most of the message strings from the kernel image
723 and makes the kernel more or less silent. As this makes it
724 very difficult to diagnose system problems, saying N here is
725 strongly discouraged.
726
Matt Mackallc8538a72005-05-01 08:59:01 -0700727config BUG
728 bool "BUG() support" if EMBEDDED
729 default y
730 help
731 Disabling this option eliminates support for BUG and WARN, reducing
732 the size of your kernel image and potentially quietly ignoring
733 numerous fatal conditions. You should only consider disabling this
734 option for embedded systems with no facilities for reporting errors.
735 Just say Y.
736
Matt Mackall708e9a72006-01-08 01:05:25 -0800737config ELF_CORE
738 default y
739 bool "Enable ELF core dumps" if EMBEDDED
740 help
741 Enable support for generating core dumps. Disabling saves about 4k.
742
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200743config PCSPKR_PLATFORM
744 bool "Enable PC-Speaker support" if EMBEDDED
745 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
746 default y
747 help
748 This option allows to disable the internal PC-Speaker
749 support, saving some memory.
750
Ingo Molnar32a93232008-02-06 22:39:44 +0100751config COMPAT_BRK
752 bool "Disable heap randomization"
753 default y
754 help
755 Randomizing heap placement makes heap exploits harder, but it
756 also breaks ancient binaries (including anything libc5 based).
757 This option changes the bootup default to heap randomization
758 disabled, and can be overriden runtime by setting
759 /proc/sys/kernel/randomize_va_space to 2.
760
Ingo Molnar166124f2008-02-09 23:24:09 +0100761 On non-ancient distros (post-2000 ones) N is usually a safe choice.
Ingo Molnar32a93232008-02-06 22:39:44 +0100762
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763config BASE_FULL
764 default y
765 bool "Enable full-sized data structures for core" if EMBEDDED
766 help
767 Disabling this option reduces the size of miscellaneous core
768 kernel data structures. This saves memory on small machines,
769 but may reduce performance.
770
771config FUTEX
772 bool "Enable futex support" if EMBEDDED
773 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700774 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 help
776 Disabling this option will cause the kernel to be built without
777 support for "fast userspace mutexes". The resulting kernel may not
778 run glibc-based applications correctly.
779
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700780config ANON_INODES
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700781 bool
Davide Libenzi5dc8bf82007-05-10 22:23:11 -0700782
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783config EPOLL
784 bool "Enable eventpoll support" if EMBEDDED
785 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700786 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 help
788 Disabling this option will cause the kernel to be built without
789 support for epoll family of system calls.
790
Davide Libenzifba2afa2007-05-10 22:23:13 -0700791config SIGNALFD
792 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700793 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700794 default y
795 help
796 Enable the signalfd() system call that allows to receive signals
797 on a file descriptor.
798
799 If unsure, say Y.
800
Davide Libenzib215e282007-05-10 22:23:16 -0700801config TIMERFD
802 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700803 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700804 default y
805 help
806 Enable the timerfd() system call that allows to receive timer
807 events on a file descriptor.
808
809 If unsure, say Y.
810
Davide Libenzie1ad7462007-05-10 22:23:19 -0700811config EVENTFD
812 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700813 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700814 default y
815 help
816 Enable the eventfd() system call that allows to receive both
817 kernel notification (ie. KAIO) or userspace notifications.
818
819 If unsure, say Y.
820
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821config SHMEM
822 bool "Use full shmem filesystem" if EMBEDDED
823 default y
824 depends on MMU
825 help
826 The shmem is an internal filesystem used to manage shared memory.
827 It is backed by swap and manages resource limits. It is also exported
828 to userspace as tmpfs if TMPFS is enabled. Disabling this
829 option replaces shmem and tmpfs with the much simpler ramfs code,
830 which may be appropriate on small systems without swap.
831
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700832config AIO
833 bool "Enable AIO support" if EMBEDDED
834 default y
835 help
836 This option enables POSIX asynchronous I/O which may by used
837 by some high performance threaded applications. Disabling
838 this option saves about 7k.
839
Christoph Lameterf8891e52006-06-30 01:55:45 -0700840config VM_EVENT_COUNTERS
841 default y
842 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
843 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -0800844 VM event counters are needed for event counts to be shown.
845 This option allows the disabling of the VM event counters
846 on EMBEDDED systems. /proc/vmstat will only show page counts
847 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -0700848
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200849config PCI_QUIRKS
850 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +0200851 bool "Enable PCI quirk workarounds" if EMBEDDED
852 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +0200853 help
854 This enables workarounds for various PCI chipset
855 bugs/quirks. Disable this only if your target machine is
856 unaffected by PCI quirks.
857
Christoph Lameter41ecc552007-05-09 02:32:44 -0700858config SLUB_DEBUG
859 default y
860 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -0700861 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -0700862 help
863 SLUB has extensive debug support features. Disabling these can
864 result in significant savings in code size. This also disables
865 SLUB sysfs support. /sys/slab will not exist and there will be
866 no support for cache validation etc.
867
Christoph Lameter81819f02007-05-06 14:49:36 -0700868choice
869 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -0700870 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700871 help
872 This option allows to select a slab allocator.
873
874config SLAB
875 bool "SLAB"
876 help
877 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -0700878 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +0000879 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -0700880
881config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -0700882 bool "SLUB (Unqueued Allocator)"
883 help
884 SLUB is a slab allocator that minimizes cache line usage
885 instead of managing queues of cached objects (SLAB approach).
886 Per cpu caching is realized using slabs of objects instead
887 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +0000888 and has enhanced diagnostics. SLUB is the default choice for
889 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -0700890
891config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -0700892 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -0700893 bool "SLOB (Simple Allocator)"
894 help
Matt Mackall37291452008-02-04 22:29:38 -0800895 SLOB replaces the stock allocator with a drastically simpler
896 allocator. SLOB is generally more space efficient but
897 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -0700898
899endchoice
900
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500901config PROFILING
902 bool "Profiling support (EXPERIMENTAL)"
903 help
904 Say Y here to enable the extended profiling support mechanisms used
905 by profilers such as OProfile.
906
Ingo Molnar5f87f112008-07-23 14:15:22 +0200907#
908# Place an empty function call at each tracepoint site. Can be
909# dynamically changed for a probe function.
910#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -0400911config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +0200912 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -0400913
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500914config MARKERS
915 bool "Activate markers"
Mathieu Desnoyersc1df1bd2008-11-14 17:47:39 -0500916 depends on TRACEPOINTS
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500917 help
918 Place an empty function call at each marker site. Can be
919 dynamically changed for a probe function.
920
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -0500921source "arch/Kconfig"
922
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923endmenu # General setup
924
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +0400925config HAVE_GENERIC_DMA_COHERENT
926 bool
927 default n
928
Linus Torvalds158a9622008-01-02 13:04:48 -0800929config SLABINFO
930 bool
931 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +0300932 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -0800933 default y
934
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700935config RT_MUTEXES
936 boolean
937 select PLIST
938
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939config BASE_SMALL
940 int
941 default 0 if BASE_FULL
942 default 1 if !BASE_FULL
943
Jan Engelhardt66da5732007-07-15 23:39:29 -0700944menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 bool "Enable loadable module support"
946 help
947 Kernel modules are small pieces of compiled code which can
948 be inserted in the running kernel, rather than being
949 permanently built into the kernel. You use the "modprobe"
950 tool to add (and sometimes remove) them. If you say Y here,
951 many parts of the kernel can be built as modules (by
952 answering M instead of Y where indicated): this is most
953 useful for infrequently used options which are not required
954 for booting. For more information, see the man pages for
955 modprobe, lsmod, modinfo, insmod and rmmod.
956
957 If you say Y here, you will need to run "make
958 modules_install" to put the modules under /lib/modules/
959 where modprobe can find them (you may need to be root to do
960 this).
961
962 If unsure, say Y.
963
Robert P. J. Day0b0de142008-08-04 13:31:32 -0400964if MODULES
965
Linus Torvalds826e4502008-05-04 17:04:16 -0700966config MODULE_FORCE_LOAD
967 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -0700968 default n
969 help
Rusty Russell91e37a72008-05-09 16:25:28 +1000970 Allow loading of modules without version information (ie. modprobe
971 --force). Forced module loading sets the 'F' (forced) taint flag and
972 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -0700973
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974config MODULE_UNLOAD
975 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 help
977 Without this option you will not be able to unload any
978 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -0500979 anyway), which makes your kernel smaller, faster
980 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
982config MODULE_FORCE_UNLOAD
983 bool "Forced module unloading"
984 depends on MODULE_UNLOAD && EXPERIMENTAL
985 help
986 This option allows you to force a module to unload, even if the
987 kernel believes it is unsafe: the kernel will remove the module
988 without waiting for anyone to stop using it (using the -f option to
989 rmmod). This is mainly for kernel developers and desperate users.
990 If unsure, say N.
991
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +0100993 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 help
995 Usually, you have to use modules compiled with your kernel.
996 Saying Y here makes it sometimes possible to use modules
997 compiled for different kernels, by adding enough information
998 to the modules to (hopefully) spot any changes which would
999 make them incompatible with the kernel you are running. If
1000 unsure, say N.
1001
1002config MODULE_SRCVERSION_ALL
1003 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 help
1005 Modules which contain a MODULE_VERSION get an extra "srcversion"
1006 field inserted into their modinfo section, which contains a
1007 sum of the source files which made it. This helps maintainers
1008 see exactly which source was used to build a module (since
1009 others sometimes change the module source without updating
1010 the version). With this option, such a "srcversion" field
1011 will be created for all modules. If unsure, say N.
1012
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001013endif # MODULES
1014
Rusty Russell98a79d62008-12-13 21:19:41 +10301015config INIT_ALL_POSSIBLE
1016 bool
1017 help
1018 Back when each arch used to define their own cpu_online_map and
1019 cpu_possible_map, some of them chose to initialize cpu_possible_map
1020 with all 1s, and others with all 0s. When they were centralised,
1021 it was better to provide this option than to break all the archs
1022 and have several arch maintainers persuing me down dark alleys.
1023
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024config STOP_MACHINE
1025 bool
1026 default y
1027 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1028 help
1029 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001030
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001031source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001032
1033config PREEMPT_NOTIFIERS
1034 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001035
Ingo Molnar12d79ba2008-12-25 09:31:28 +01001036choice
1037 prompt "RCU Implementation"
1038 default CLASSIC_RCU
1039
Paul E. McKenneye260be62008-01-25 21:08:24 +01001040config CLASSIC_RCU
Ingo Molnar12d79ba2008-12-25 09:31:28 +01001041 bool "Classic RCU"
Paul E. McKenneye260be62008-01-25 21:08:24 +01001042 help
1043 This option selects the classic RCU implementation that is
1044 designed for best read-side performance on non-realtime
Ingo Molnar12d79ba2008-12-25 09:31:28 +01001045 systems.
1046
1047 Select this option if you are unsure.
1048
1049config TREE_RCU
1050 bool "Tree-based hierarchical RCU"
1051 help
1052 This option selects the RCU implementation that is
1053 designed for very large SMP system with hundreds or
1054 thousands of CPUs.
1055
1056config PREEMPT_RCU
1057 bool "Preemptible RCU"
1058 depends on PREEMPT
1059 help
1060 This option reduces the latency of the kernel by making certain
1061 RCU sections preemptible. Normally RCU code is non-preemptible, if
1062 this option is selected then read-only RCU sections become
1063 preemptible. This helps latency, but may expose bugs due to
1064 now-naive assumptions about each RCU read-side critical section
1065 remaining on a given CPU through its execution.
1066
1067endchoice
1068
1069config RCU_TRACE
1070 bool "Enable tracing for RCU"
1071 depends on TREE_RCU || PREEMPT_RCU
1072 help
1073 This option provides tracing in RCU which presents stats
1074 in debugfs for debugging RCU implementation.
1075
1076 Say Y here if you want to enable RCU tracing
1077 Say N if you are unsure.
1078
1079config RCU_FANOUT
1080 int "Tree-based hierarchical RCU fanout value"
1081 range 2 64 if 64BIT
1082 range 2 32 if !64BIT
1083 depends on TREE_RCU
1084 default 64 if 64BIT
1085 default 32 if !64BIT
1086 help
1087 This option controls the fanout of hierarchical implementations
1088 of RCU, allowing RCU to work efficiently on machines with
1089 large numbers of CPUs. This value must be at least the cube
1090 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
1091 systems and up to 262,144 for 64-bit systems.
1092
1093 Select a specific number if testing RCU itself.
1094 Take the default if unsure.
1095
1096config RCU_FANOUT_EXACT
1097 bool "Disable tree-based hierarchical RCU auto-balancing"
1098 depends on TREE_RCU
1099 default n
1100 help
1101 This option forces use of the exact RCU_FANOUT value specified,
1102 regardless of imbalances in the hierarchy. This is useful for
1103 testing RCU itself, and might one day be useful on systems with
1104 strong NUMA behavior.
1105
1106 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
1107
1108 Say N if unsure.
1109
Paul E. McKenney64db4cf2008-12-18 21:55:32 +01001110config TREE_RCU_TRACE
1111 def_bool RCU_TRACE && TREE_RCU
1112 select DEBUG_FS
Paul E. McKenneye260be62008-01-25 21:08:24 +01001113 help
Paul E. McKenney64db4cf2008-12-18 21:55:32 +01001114 This option provides tracing for the TREE_RCU implementation,
1115 permitting Makefile to trivially select kernel/rcutree_trace.c.
1116
1117config PREEMPT_RCU_TRACE
1118 def_bool RCU_TRACE && PREEMPT_RCU
1119 select DEBUG_FS
1120 help
1121 This option provides tracing for the PREEMPT_RCU implementation,
1122 permitting Makefile to trivially select kernel/rcupreempt_trace.c.