blob: e0a22e42d39a08b4745eac250389dd4bd1799ac7 [file] [log] [blame]
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' Giarrussob2670ea2006-10-19 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
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
22 default y
23
Peter Zijlstrae360adb2010-10-14 14:01:34 +080024config HAVE_IRQ_WORK
25 bool
26
27config IRQ_WORK
28 bool
29 depends on HAVE_IRQ_WORK
30
Al Boldiff0cfc62007-07-31 00:39:23 -070031menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33config EXPERIMENTAL
34 bool "Prompt for development and/or incomplete code/drivers"
35 ---help---
36 Some of the various things that Linux supports (such as network
37 drivers, file systems, network protocols, etc.) can be in a state
38 of development where the functionality, stability, or the level of
39 testing is not yet high enough for general use. This is usually
40 known as the "alpha-test" phase among developers. If a feature is
41 currently in alpha-test, then the developers usually discourage
42 uninformed widespread use of this feature by the general public to
43 avoid "Why doesn't this work?" type mail messages. However, active
44 testing and use of these systems is welcomed. Just be aware that it
45 may not meet the normal level of reliability or it may fail to work
46 in some special cases. Detailed bug reports from people familiar
47 with the kernel internals are usually welcomed by the developers
48 (before submitting bug reports, please read the documents
49 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
50 <file:Documentation/BUG-HUNTING>, and
51 <file:Documentation/oops-tracing.txt> in the kernel source).
52
53 This option will also make obsoleted drivers available. These are
54 drivers that have been replaced by something else, and/or are
55 scheduled to be removed in a future kernel release.
56
57 Unless you intend to help test and develop a feature or driver that
58 falls into this category, or you have a situation that requires
59 using these features, you should probably say N here, which will
60 cause the configurator to present you with fewer choices. If
61 you say Y here, you will be offered the choice of using features or
62 drivers that are currently considered to be in the alpha-test phase.
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064config BROKEN
65 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67config BROKEN_ON_SMP
68 bool
69 depends on BROKEN || !SMP
70 default y
71
Linus Torvalds1da177e2005-04-16 15:20:36 -070072config INIT_ENV_ARG_LIMIT
73 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070074 default 32 if !UML
75 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080077 Maximum of each of the number of arguments and environment
78 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Roland McGrath84336462009-12-21 16:24:06 -080081config CROSS_COMPILE
82 string "Cross-compiler tool prefix"
83 help
84 Same as running 'make CROSS_COMPILE=prefix-' but stored for
85 default make runs in this kernel build directory. You don't
86 need to set this unless you want the configured kernel build
87 directory to select the cross-compiler automatically.
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089config LOCALVERSION
90 string "Local version - append to kernel release"
91 help
92 Append an extra string to the end of your kernel version.
93 This will show up when you type uname, for example.
94 The string you set here will be appended after the contents of
95 any files with a filename matching localversion* in your
96 object and source tree, in that order. Your total string can
97 be a maximum of 64 characters.
98
Ryan Andersonaaebf432005-07-31 04:57:49 -040099config LOCALVERSION_AUTO
100 bool "Automatically append version information to the version string"
101 default y
102 help
103 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200104 release tree by looking for git tags that belong to the current
105 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400106
107 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200108 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400109 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200112 (The actual string used here is the first eight characters produced
113 by running the command:
114
115 $ git rev-parse --verify HEAD
116
117 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400118
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119config HAVE_KERNEL_GZIP
120 bool
121
122config HAVE_KERNEL_BZIP2
123 bool
124
125config HAVE_KERNEL_LZMA
126 bool
127
Lasse Collin3ebe1242011-01-12 17:01:23 -0800128config HAVE_KERNEL_XZ
129 bool
130
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800131config HAVE_KERNEL_LZO
132 bool
133
Alain Knaff30d65db2009-01-04 22:46:17 +0100134choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800135 prompt "Kernel compression mode"
136 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800137 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800138 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100139 The linux kernel is a kind of self-extracting executable.
140 Several compression algorithms are available, which differ
141 in efficiency, compression and decompression speed.
142 Compression speed is only relevant when building a kernel.
143 Decompression speed is relevant at each boot.
144
145 If you have any problems with bzip2 or lzma compressed
146 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
147 version of this functionality (bzip2 only), for 2.4, was
148 supplied by Christian Ludwig)
149
150 High compression options are mostly useful for users, who
151 are low on disk space (embedded systems), but for whom ram
152 size matters less.
153
154 If in doubt, select 'gzip'
155
156config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800157 bool "Gzip"
158 depends on HAVE_KERNEL_GZIP
159 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800160 The old and tried gzip compression. It provides a good balance
161 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100162
163config KERNEL_BZIP2
164 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800165 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100166 help
167 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800168 Decompression speed is slowest among the three. The kernel
169 size is about 10% smaller with bzip2, in comparison to gzip.
170 Bzip2 uses a large amount of memory. For modern kernels you
171 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100172
173config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800174 bool "LZMA"
175 depends on HAVE_KERNEL_LZMA
176 help
177 The most recent compression algorithm.
178 Its ratio is best, decompression speed is between the other
179 two. Compression is slowest. The kernel size is about 33%
180 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100181
Lasse Collin3ebe1242011-01-12 17:01:23 -0800182config KERNEL_XZ
183 bool "XZ"
184 depends on HAVE_KERNEL_XZ
185 help
186 XZ uses the LZMA2 algorithm and instruction set specific
187 BCJ filters which can improve compression ratio of executable
188 code. The size of the kernel is about 30% smaller with XZ in
189 comparison to gzip. On architectures for which there is a BCJ
190 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
191 will create a few percent smaller kernel than plain LZMA.
192
193 The speed is about the same as with LZMA: The decompression
194 speed of XZ is better than that of bzip2 but worse than gzip
195 and LZO. Compression is slow.
196
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800197config KERNEL_LZO
198 bool "LZO"
199 depends on HAVE_KERNEL_LZO
200 help
201 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200202 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800203 (both compression and decompression) is the fastest.
204
Alain Knaff30d65db2009-01-04 22:46:17 +0100205endchoice
206
Josh Triplettbd5dc172011-06-15 15:08:28 -0700207config DEFAULT_HOSTNAME
208 string "Default hostname"
209 default "(none)"
210 help
211 This option determines the default system hostname before userspace
212 calls sethostname(2). The kernel traditionally uses "(none)" here,
213 but you may wish to use a different default here to make a minimal
214 system more usable with less configuration.
215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216config SWAP
217 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200218 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 default y
220 help
221 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100222 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 used to provide more virtual memory than the actual RAM present
224 in your computer. If unsure say Y.
225
226config SYSVIPC
227 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 ---help---
229 Inter Process Communication is a suite of library functions and
230 system calls which let processes (running programs) synchronize and
231 exchange information. It is generally considered to be a good thing,
232 and some programs won't run unless you say Y here. In particular, if
233 you want to run the DOS emulator dosemu under Linux (read the
234 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
235 you'll need to say Y here.
236
237 You can find documentation about IPC with "info ipc" and also in
238 section 6.4 of the Linux Programmer's Guide, available from
239 <http://www.tldp.org/guides.html>.
240
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800241config SYSVIPC_SYSCTL
242 bool
243 depends on SYSVIPC
244 depends on SYSCTL
245 default y
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247config POSIX_MQUEUE
248 bool "POSIX Message Queues"
249 depends on NET && EXPERIMENTAL
250 ---help---
251 POSIX variant of message queues is a part of IPC. In POSIX message
252 queues every message has a priority which decides about succession
253 of receiving it by a process. If you want to compile and run
254 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200255 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257 POSIX message queues are visible as a filesystem called 'mqueue'
258 and can be mounted somewhere if you want to do filesystem
259 operations on message queues.
260
261 If unsure, say Y.
262
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700263config POSIX_MQUEUE_SYSCTL
264 bool
265 depends on POSIX_MQUEUE
266 depends on SYSCTL
267 default y
268
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269config BSD_PROCESS_ACCT
270 bool "BSD Process Accounting"
271 help
272 If you say Y here, a user level program will be able to instruct the
273 kernel (via a special system call) to write process accounting
274 information to a file: whenever a process exits, information about
275 that process will be appended to the file by the kernel. The
276 information includes things such as creation time, owning user,
277 command name, memory usage, controlling terminal etc. (the complete
278 list is in the struct acct in <file:include/linux/acct.h>). It is
279 up to the user level program to do useful things with this
280 information. This is generally a good idea, so say Y.
281
282config BSD_PROCESS_ACCT_V3
283 bool "BSD Process Accounting version 3 file format"
284 depends on BSD_PROCESS_ACCT
285 default n
286 help
287 If you say Y here, the process accounting information is written
288 in a new file format that also logs the process IDs of each
289 process and it's parent. Note that this file format is incompatible
290 with previous v0/v1/v2 file formats, so you will need updated tools
291 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300292 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530294config FHANDLE
295 bool "open by fhandle syscalls"
296 select EXPORTFS
297 help
298 If you say Y here, a user level program will be able to map
299 file names to handle and then later use the handle for
300 different file system operations. This is useful in implementing
301 userspace file servers, which now track files using handles instead
302 of names. The handle would remain the same even if file names
303 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
304 syscalls.
305
Shailabh Nagarc7572492006-07-14 00:24:40 -0700306config TASKSTATS
307 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
308 depends on NET
309 default n
310 help
311 Export selected statistics for tasks/processes through the
312 generic netlink interface. Unlike BSD process accounting, the
313 statistics are available during the lifetime of tasks/processes as
314 responses to commands. Like BSD accounting, they are sent to user
315 space on task exit.
316
317 Say N if unsure.
318
Shailabh Nagarca74e922006-07-14 00:24:36 -0700319config TASK_DELAY_ACCT
320 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700321 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700322 help
323 Collect information on time spent by a task waiting for system
324 resources like cpu, synchronous block I/O completion and swapping
325 in pages. Such statistics can help in setting a task's priorities
326 relative to other tasks for cpu, io, rss limits etc.
327
328 Say N if unsure.
329
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800330config TASK_XACCT
331 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
332 depends on TASKSTATS
333 help
334 Collect extended task accounting data and send the data
335 to userland for processing over the taskstats interface.
336
337 Say N if unsure.
338
339config TASK_IO_ACCOUNTING
340 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
341 depends on TASK_XACCT
342 help
343 Collect information on the number of bytes of storage I/O which this
344 task has caused.
345
346 Say N if unsure.
347
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348config AUDIT
349 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100350 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 help
352 Enable auditing infrastructure that can be used with another
353 kernel subsystem, such as SELinux (which requires this for
354 logging of avc messages output). Does not do system-call
355 auditing without CONFIG_AUDITSYSCALL.
356
357config AUDITSYSCALL
358 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000359 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 default y if SECURITY_SELINUX
361 help
362 Enable low-overhead system-call auditing infrastructure that
363 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500364 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
Eric Paris939a67f2009-12-17 20:12:06 -0500366config AUDIT_WATCH
367 def_bool y
368 depends on AUDITSYSCALL
369 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Al Viro74c3cbe2007-07-22 08:04:18 -0400371config AUDIT_TREE
372 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400373 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500374 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400375
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000376source "kernel/irq/Kconfig"
377
Mike Travisc903ff82009-01-15 12:28:29 -0800378menu "RCU Subsystem"
379
380choice
381 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700382 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800383
Mike Travisc903ff82009-01-15 12:28:29 -0800384config TREE_RCU
385 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700386 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800387 help
388 This option selects the RCU implementation that is
389 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700390 thousands of CPUs. It also scales down nicely to
391 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800392
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700393config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700394 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700395 depends on PREEMPT
396 help
397 This option selects the RCU implementation that is
398 designed for very large SMP systems with hundreds or
399 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700400 is also required. It also scales down nicely to
401 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700402
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700403config TINY_RCU
404 bool "UP-only small-memory-footprint RCU"
405 depends on !SMP
406 help
407 This option selects the RCU implementation that is
408 designed for UP systems from which real-time response
409 is not required. This option greatly reduces the
410 memory footprint of RCU.
411
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700412config TINY_PREEMPT_RCU
413 bool "Preemptible UP-only small-memory-footprint RCU"
414 depends on !SMP && PREEMPT
415 help
416 This option selects the RCU implementation that is designed
417 for real-time UP systems. This option greatly reduces the
418 memory footprint of RCU.
419
Mike Travisc903ff82009-01-15 12:28:29 -0800420endchoice
421
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700422config PREEMPT_RCU
423 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
424 help
425 This option enables preemptible-RCU code that is common between
426 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
427
Mike Travisc903ff82009-01-15 12:28:29 -0800428config RCU_TRACE
429 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800430 help
431 This option provides tracing in RCU which presents stats
432 in debugfs for debugging RCU implementation.
433
434 Say Y here if you want to enable RCU tracing
435 Say N if you are unsure.
436
437config RCU_FANOUT
438 int "Tree-based hierarchical RCU fanout value"
439 range 2 64 if 64BIT
440 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700441 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800442 default 64 if 64BIT
443 default 32 if !64BIT
444 help
445 This option controls the fanout of hierarchical implementations
446 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700447 large numbers of CPUs. This value must be at least the fourth
448 root of NR_CPUS, which allows NR_CPUS to be insanely large.
449 The default value of RCU_FANOUT should be used for production
450 systems, but if you are stress-testing the RCU implementation
451 itself, small RCU_FANOUT values allow you to test large-system
452 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800453
454 Select a specific number if testing RCU itself.
455 Take the default if unsure.
456
457config RCU_FANOUT_EXACT
458 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700459 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800460 default n
461 help
462 This option forces use of the exact RCU_FANOUT value specified,
463 regardless of imbalances in the hierarchy. This is useful for
464 testing RCU itself, and might one day be useful on systems with
465 strong NUMA behavior.
466
467 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
468
469 Say N if unsure.
470
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800471config RCU_FAST_NO_HZ
472 bool "Accelerate last non-dyntick-idle CPU's grace periods"
473 depends on TREE_RCU && NO_HZ && SMP
474 default n
475 help
476 This option causes RCU to attempt to accelerate grace periods
477 in order to allow the final CPU to enter dynticks-idle state
478 more quickly. On the other hand, this option increases the
479 overhead of the dynticks-idle checking, particularly on systems
480 with large numbers of CPUs.
481
482 Say Y if energy efficiency is critically important, particularly
483 if you have relatively few CPUs.
484
485 Say N if you are unsure.
486
Mike Travisc903ff82009-01-15 12:28:29 -0800487config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700488 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800489 select DEBUG_FS
490 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700491 This option provides tracing for the TREE_RCU and
492 TREE_PREEMPT_RCU implementations, permitting Makefile to
493 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800494
Paul E. McKenney24278d12010-09-27 17:25:23 -0700495config RCU_BOOST
496 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800497 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700498 default n
499 help
500 This option boosts the priority of preempted RCU readers that
501 block the current preemptible RCU grace period for too long.
502 This option also prevents heavy loads from blocking RCU
503 callback invocation for all flavors of RCU.
504
505 Say Y here if you are working with real-time apps or heavy loads
506 Say N here if you are unsure.
507
508config RCU_BOOST_PRIO
509 int "Real-time priority to boost RCU readers to"
510 range 1 99
511 depends on RCU_BOOST
512 default 1
513 help
514 This option specifies the real-time priority to which preempted
515 RCU readers are to be boosted. If you are working with CPU-bound
516 real-time applications, you should specify a priority higher then
517 the highest-priority CPU-bound application.
518
519 Specify the real-time priority, or take the default if unsure.
520
521config RCU_BOOST_DELAY
522 int "Milliseconds to delay boosting after RCU grace-period start"
523 range 0 3000
524 depends on RCU_BOOST
525 default 500
526 help
527 This option specifies the time to wait after the beginning of
528 a given grace period before priority-boosting preempted RCU
529 readers blocking that grace period. Note that any RCU reader
530 blocking an expedited RCU grace period is boosted immediately.
531
532 Accept the default if unsure.
533
Mike Travisc903ff82009-01-15 12:28:29 -0800534endmenu # "RCU Subsystem"
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700537 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 ---help---
539 This option enables the complete Linux kernel ".config" file
540 contents to be saved in the kernel. It provides documentation
541 of which kernel options are used in a running kernel or in an
542 on-disk kernel. This information can be extracted from the kernel
543 image file with the script scripts/extract-ikconfig and used as
544 input to rebuild the current kernel or to build another kernel.
545 It can also be extracted from a running kernel by reading
546 /proc/config.gz if enabled (below).
547
548config IKCONFIG_PROC
549 bool "Enable access to .config through /proc/config.gz"
550 depends on IKCONFIG && PROC_FS
551 ---help---
552 This option enables access to the kernel configuration file
553 through /proc/config.gz.
554
Alistair John Strachan794543a2007-05-08 00:31:15 -0700555config LOG_BUF_SHIFT
556 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
557 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700558 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700559 help
560 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700561 Examples:
562 17 => 128 KB
563 16 => 64 KB
564 15 => 32 KB
565 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700566 13 => 8 KB
567 12 => 4 KB
568
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800569#
570# Architectures with an unreliable sched_clock() should select this:
571#
572config HAVE_UNSTABLE_SCHED_CLOCK
573 bool
574
Li Zefan23964d22009-01-15 13:50:58 -0800575menuconfig CGROUPS
576 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800577 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700578 help
Li Zefan23964d22009-01-15 13:50:58 -0800579 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800580 use with process control subsystems such as Cpusets, CFS, memory
581 controls or device isolation.
582 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800583 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800584 - Documentation/cgroups/ (features for grouping, isolation
585 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700586
587 Say N if unsure.
588
Li Zefan23964d22009-01-15 13:50:58 -0800589if CGROUPS
590
Paul Menage006cb992007-10-18 23:39:43 -0700591config CGROUP_DEBUG
592 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700593 default n
Paul Menage006cb992007-10-18 23:39:43 -0700594 help
595 This option enables a simple cgroup subsystem that
596 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800597 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700598
Li Zefan23964d22009-01-15 13:50:58 -0800599 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700600
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700601config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800602 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800603 help
604 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700605 cgroup.
606
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700607config CGROUP_DEVICE
608 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700609 help
610 Provides a cgroup implementing whitelists for devices which
611 a process in the cgroup can mknod or open.
612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613config CPUSETS
614 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700616 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 allow dynamically partitioning a system into sets of CPUs and
618 Memory Nodes and assigning tasks to run only within those sets.
619 This is primarily useful on large SMP or NUMA systems.
620
621 Say N if unsure.
622
Li Zefan23964d22009-01-15 13:50:58 -0800623config PROC_PID_CPUSET
624 bool "Include legacy /proc/<pid>/cpuset file"
625 depends on CPUSETS
626 default y
627
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100628config CGROUP_CPUACCT
629 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100630 help
631 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800632 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100633
Pavel Emelianove552b662008-02-07 00:13:49 -0800634config RESOURCE_COUNTERS
635 bool "Resource counters"
636 help
637 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800638 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800639
Balbir Singh00f0b822008-03-04 14:28:39 -0800640config CGROUP_MEM_RES_CTLR
641 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700642 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700643 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800644 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700645 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100646 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800647
648 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700649 associated with each page of memory in the system. By this,
650 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
651 usage tracking struct at boot. Total amount of this is printed out
652 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800653
654 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700655 sure you need the memory resource controller. Even when you enable
656 this, you can set "cgroup_disable=memory" at your boot option to
657 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800658 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800659
Balbir Singhcf475ad2008-04-29 01:00:16 -0700660 This config option also selects MM_OWNER config option, which
661 could in turn add some fork/exit overhead.
662
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800663config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700664 bool "Memory Resource Controller Swap Extension"
665 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800666 help
667 Add swap management feature to memory resource controller. When you
668 enable this, you can limit mem+swap usage per cgroup. In other words,
669 when you disable this, memory resource controller has no cares to
670 usage of swap...a process can exhaust all of the swap. This extension
671 is useful when you want to avoid exhaustion swap but this itself
672 adds more overheads and consumes memory for remembering information.
673 Especially if you use 32bit system or small memory system, please
674 be careful about enabling this. When memory resource controller
675 is disabled by boot option, this will be automatically disabled and
676 there will be no overhead from this. Even when you set this config=y,
677 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700678 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
679 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800680config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
681 bool "Memory Resource Controller Swap Extension enabled by default"
682 depends on CGROUP_MEM_RES_CTLR_SWAP
683 default y
684 help
685 Memory Resource Controller Swap Extension comes with its price in
686 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700687 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800688 and let the user enable it by swapaccount boot command line
689 parameter should have this option unselected.
690 For those who want to have the feature enabled by default should
691 select this option (if, for some reason, they need to disable it
692 then noswapaccount does the trick).
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800693
Stephane Eraniane5d13672011-02-14 11:20:01 +0200694config CGROUP_PERF
695 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
696 depends on PERF_EVENTS && CGROUPS
697 help
698 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800699 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200700 designated cpu.
701
702 Say N if unsure.
703
Dhaval Giani7c941432010-01-20 13:26:18 +0100704menuconfig CGROUP_SCHED
705 bool "Group CPU scheduler"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700706 depends on EXPERIMENTAL
Dhaval Giani7c941432010-01-20 13:26:18 +0100707 default n
708 help
709 This feature lets CPU scheduler recognize task groups and control CPU
710 bandwidth allocation to such task groups. It uses cgroups to group
711 tasks.
712
713if CGROUP_SCHED
714config FAIR_GROUP_SCHED
715 bool "Group scheduling for SCHED_OTHER"
716 depends on CGROUP_SCHED
717 default CGROUP_SCHED
718
719config RT_GROUP_SCHED
720 bool "Group scheduling for SCHED_RR/FIFO"
721 depends on EXPERIMENTAL
722 depends on CGROUP_SCHED
723 default n
724 help
725 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800726 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100727 schedule realtime tasks for non-root users until you allocate
728 realtime bandwidth for them.
729 See Documentation/scheduler/sched-rt-group.txt for more information.
730
731endif #CGROUP_SCHED
732
Vivek Goyalafc24d42010-04-26 19:27:56 +0200733config BLK_CGROUP
734 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700735 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200736 default n
737 ---help---
738 Generic block IO controller cgroup interface. This is the common
739 cgroup interface which should be used by various IO controlling
740 policies.
741
742 Currently, CFQ IO scheduler uses it to recognize task groups and
743 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400744 to such task groups. It is also used by bio throttling logic in
745 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200746
747 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400748 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000749 enabling proportional weight division of disk bandwidth in CFQ, set
750 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000751 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200752
753 See Documentation/cgroups/blkio-controller.txt for more information.
754
755config DEBUG_BLK_CGROUP
756 bool "Enable Block IO controller debugging"
757 depends on BLK_CGROUP
758 default n
759 ---help---
760 Enable some debugging help. Currently it exports additional stat
761 files in a cgroup which can be useful for debugging.
762
Li Zefan23964d22009-01-15 13:50:58 -0800763endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800764
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700765menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800766 bool "Namespaces support" if EXPERT
767 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800768 help
769 Provides the way to make tasks work with different objects using
770 the same id. For example same IPC id may refer to different objects
771 or same user id or pid may refer to different tasks when used in
772 different namespaces.
773
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700774if NAMESPACES
775
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800776config UTS_NS
777 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700778 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800779 help
780 In this namespace tasks see different info provided with the
781 uname() system call
782
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800783config IPC_NS
784 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700785 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700786 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800787 help
788 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700789 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800790
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800791config USER_NS
792 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700793 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700794 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800795 help
796 This allows containers, i.e. vservers, to use user namespaces
797 to provide different user info for different servers.
798 If unsure, say N.
799
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800800config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700801 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700802 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800803 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300804 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100805 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800806 pid namespaces. This is a building block of containers.
807
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800808config NET_NS
809 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700810 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700811 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800812 help
813 Allow user space to create what appear to be multiple instances
814 of the network stack.
815
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700816endif # NAMESPACES
817
Mike Galbraith5091faa2010-11-30 14:18:03 +0100818config SCHED_AUTOGROUP
819 bool "Automatic process group scheduling"
820 select EVENTFD
821 select CGROUPS
822 select CGROUP_SCHED
823 select FAIR_GROUP_SCHED
824 help
825 This option optimizes the scheduler for common desktop workloads by
826 automatically creating and populating task groups. This separation
827 of workloads isolates aggressive CPU burners (like build jobs) from
828 desktop applications. Task group autogeneration is currently based
829 upon task session.
830
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700831config MM_OWNER
832 bool
833
834config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100835 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700836 depends on SYSFS
837 default n
838 help
839 This option adds code that switches the layout of the "block" class
840 devices, to not show up in /sys/class/block/, but only in
841 /sys/block/.
842
843 This switch is only active when the sysfs.deprecated=1 boot option is
844 passed or the SYSFS_DEPRECATED_V2 option is set.
845
846 This option allows new kernels to run on old distributions and tools,
847 which might get confused by /sys/class/block/. Since 2007/2008 all
848 major distributions and tools handle this just fine.
849
850 Recent distributions and userspace tools after 2009/2010 depend on
851 the existence of /sys/class/block/, and will not work with this
852 option enabled.
853
854 Only if you are using a new kernel on an old distribution, you might
855 need to say Y here.
856
857config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100858 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700859 default n
860 depends on SYSFS
861 depends on SYSFS_DEPRECATED
862 help
863 Enable deprecated sysfs by default.
864
865 See the CONFIG_SYSFS_DEPRECATED option for more details about this
866 option.
867
868 Only if you are using a new kernel on an old distribution, you might
869 need to say Y here. Even then, odds are you would not need it
870 enabled, you can always pass the boot option if absolutely necessary.
871
872config RELAY
873 bool "Kernel->user space relay support (formerly relayfs)"
874 help
875 This option enables support for relay interface support in
876 certain file systems (such as debugfs).
877 It is designed to provide an efficient mechanism for tools and
878 facilities to relay large amounts of data from kernel space to
879 user space.
880
881 If unsure, say N.
882
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800883config BLK_DEV_INITRD
884 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
885 depends on BROKEN || !FRV
886 help
887 The initial RAM filesystem is a ramfs which is loaded by the
888 boot loader (loadlin or lilo) and that is mounted as root
889 before the normal boot procedure. It is typically used to
890 load modules needed to mount the "real" root file system,
891 etc. See <file:Documentation/initrd.txt> for details.
892
893 If RAM disk support (BLK_DEV_RAM) is also included, this
894 also enables initial RAM disk (initrd) support and adds
895 15 Kbytes (more on some other architectures) to the kernel size.
896
897 If unsure say Y.
898
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800899if BLK_DEV_INITRD
900
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200901source "usr/Kconfig"
902
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800903endif
904
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800905config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200906 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800907 help
908 Enabling this option will pass "-Os" instead of "-O2" to gcc
909 resulting in a smaller kernel.
910
jkacur775a7222008-07-16 00:31:16 +0200911 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800912
Randy Dunlap08470622006-09-30 23:28:13 -0700913config SYSCTL
914 bool
915
Randy Dunlapb943c462009-03-10 12:55:46 -0700916config ANON_INODES
917 bool
918
David Rientjes6a108a12011-01-20 14:44:16 -0800919menuconfig EXPERT
920 bool "Configure standard kernel features (expert users)"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 help
922 This option allows certain base kernel options and settings
923 to be disabled or tweaked. This is for specialized
924 environments which can tolerate a "non-standard" kernel.
925 Only use this if you really know what you are doing.
926
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700927config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800928 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700929 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 -0700930 default y
931 help
932 This enables the legacy 16-bit UID syscall wrappers.
933
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700934config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800935 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800936 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800937 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700938 select SYSCTL
939 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800940 sys_sysctl uses binary paths that have been found challenging
941 to properly maintain and use. The interface in /proc/sys
942 using paths with ascii names is now the primary path to this
943 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700944
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800945 Almost nothing using the binary sysctl interface so if you are
946 trying to save some space it is probably safe to disable this,
947 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700948
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800949 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700950
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800952 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 default y
954 help
955 Say Y here to let the kernel print out symbolic crash information and
956 symbolic stack backtraces. This increases the size of the kernel
957 somewhat, as all symbols have to be loaded into the kernel image.
958
959config KALLSYMS_ALL
960 bool "Include all symbols in kallsyms"
961 depends on DEBUG_KERNEL && KALLSYMS
962 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300963 Normally kallsyms only contains the symbols of functions for nicer
964 OOPS messages and backtraces (i.e., symbols from the text and inittext
965 sections). This is sufficient for most cases. And only in very rare
966 cases (e.g., when a debugger is used) all symbols are required (e.g.,
967 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300969 This option makes sure that all symbols are loaded into the kernel
970 image (i.e., symbols from all sections) in cost of increased kernel
971 size (depending on the kernel configuration, it may be 300KiB or
972 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300974 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -0700975
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800976config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -0800977 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800978 default y
979 help
980 This option is provided for the case where no hotplug or uevent
981 capabilities is wanted by the kernel. You should only consider
982 disabling this option for embedded systems that do not use modules, a
983 dynamic /dev tree, or dynamic device discovery. Just say Y.
984
Matt Mackalld59745c2005-05-01 08:59:02 -0700985config PRINTK
986 default y
David Rientjes6a108a12011-01-20 14:44:16 -0800987 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -0700988 help
989 This option enables normal printk support. Removing it
990 eliminates most of the message strings from the kernel image
991 and makes the kernel more or less silent. As this makes it
992 very difficult to diagnose system problems, saying N here is
993 strongly discouraged.
994
Matt Mackallc8538a72005-05-01 08:59:01 -0700995config BUG
David Rientjes6a108a12011-01-20 14:44:16 -0800996 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -0700997 default y
998 help
999 Disabling this option eliminates support for BUG and WARN, reducing
1000 the size of your kernel image and potentially quietly ignoring
1001 numerous fatal conditions. You should only consider disabling this
1002 option for embedded systems with no facilities for reporting errors.
1003 Just say Y.
1004
Matt Mackall708e9a72006-01-08 01:05:25 -08001005config ELF_CORE
1006 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001007 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001008 help
1009 Enable support for generating core dumps. Disabling saves about 4k.
1010
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001011config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001012 bool "Enable PC-Speaker support" if EXPERT
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001013 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
1014 default y
1015 help
1016 This option allows to disable the internal PC-Speaker
1017 support, saving some memory.
1018
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019config BASE_FULL
1020 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001021 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 help
1023 Disabling this option reduces the size of miscellaneous core
1024 kernel data structures. This saves memory on small machines,
1025 but may reduce performance.
1026
1027config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001028 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -07001030 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 help
1032 Disabling this option will cause the kernel to be built without
1033 support for "fast userspace mutexes". The resulting kernel may not
1034 run glibc-based applications correctly.
1035
1036config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001037 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001039 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 help
1041 Disabling this option will cause the kernel to be built without
1042 support for epoll family of system calls.
1043
Davide Libenzifba2afa2007-05-10 22:23:13 -07001044config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001045 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001046 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001047 default y
1048 help
1049 Enable the signalfd() system call that allows to receive signals
1050 on a file descriptor.
1051
1052 If unsure, say Y.
1053
Davide Libenzib215e282007-05-10 22:23:16 -07001054config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001055 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001056 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001057 default y
1058 help
1059 Enable the timerfd() system call that allows to receive timer
1060 events on a file descriptor.
1061
1062 If unsure, say Y.
1063
Davide Libenzie1ad7462007-05-10 22:23:19 -07001064config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001065 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001066 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001067 default y
1068 help
1069 Enable the eventfd() system call that allows to receive both
1070 kernel notification (ie. KAIO) or userspace notifications.
1071
1072 If unsure, say Y.
1073
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001075 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 default y
1077 depends on MMU
1078 help
1079 The shmem is an internal filesystem used to manage shared memory.
1080 It is backed by swap and manages resource limits. It is also exported
1081 to userspace as tmpfs if TMPFS is enabled. Disabling this
1082 option replaces shmem and tmpfs with the much simpler ramfs code,
1083 which may be appropriate on small systems without swap.
1084
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001085config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001086 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001087 default y
1088 help
1089 This option enables POSIX asynchronous I/O which may by used
1090 by some high performance threaded applications. Disabling
1091 this option saves about 7k.
1092
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001093config EMBEDDED
1094 bool "Embedded system"
1095 select EXPERT
1096 help
1097 This option should be enabled if compiling the kernel for
1098 an embedded system so certain expert options are available
1099 for configuration.
1100
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001101config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001102 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001103 help
1104 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001105
Peter Zijlstra906010b2009-09-21 16:08:49 +02001106config PERF_USE_VMALLOC
1107 bool
1108 help
1109 See tools/perf/design.txt for details
1110
Ingo Molnar57c0c152009-09-21 12:20:38 +02001111menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001112
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001113config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001114 bool "Kernel performance events and counters"
1115 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001116 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001117 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001118 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001119 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001120 Enable kernel support for various performance events provided
1121 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001122
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001123 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001124 use of generic tracepoints.
1125
1126 Most modern CPUs support performance events via performance
1127 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001128 types of hw events: such as instructions executed, cachemisses
1129 suffered, or branches mis-predicted - without slowing down the
1130 kernel or applications. These registers can also trigger interrupts
1131 when a threshold number of events have passed - and can thus be
1132 used to profile the code that runs on that CPU.
1133
Ingo Molnar57c0c152009-09-21 12:20:38 +02001134 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001135 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001136 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001137 provides per task and per CPU counters, and it provides event
1138 capabilities on top of those.
1139
1140 Say Y if unsure.
1141
Ingo Molnar57c0c152009-09-21 12:20:38 +02001142config PERF_COUNTERS
1143 bool "Kernel performance counters (old config option)"
1144 depends on HAVE_PERF_EVENTS
1145 help
1146 This config has been obsoleted by the PERF_EVENTS
1147 config option - please see that one for details.
1148
1149 It has no effect on the kernel whether you enable
1150 it or not, it is a compatibility placeholder.
1151
1152 Say N if unsure.
1153
Peter Zijlstra906010b2009-09-21 16:08:49 +02001154config DEBUG_PERF_USE_VMALLOC
1155 default n
1156 bool "Debug: use vmalloc to back perf mmap() buffers"
1157 depends on PERF_EVENTS && DEBUG_KERNEL
1158 select PERF_USE_VMALLOC
1159 help
1160 Use vmalloc memory to back perf mmap() buffers.
1161
1162 Mostly useful for debugging the vmalloc code on platforms
1163 that don't require it.
1164
1165 Say N if unsure.
1166
Thomas Gleixner0793a612008-12-04 20:12:29 +01001167endmenu
1168
Christoph Lameterf8891e52006-06-30 01:55:45 -07001169config VM_EVENT_COUNTERS
1170 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001171 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001172 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001173 VM event counters are needed for event counts to be shown.
1174 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001175 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001176 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001177
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001178config PCI_QUIRKS
1179 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001180 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001181 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001182 help
1183 This enables workarounds for various PCI chipset
1184 bugs/quirks. Disable this only if your target machine is
1185 unaffected by PCI quirks.
1186
Christoph Lameter41ecc552007-05-09 02:32:44 -07001187config SLUB_DEBUG
1188 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001189 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001190 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001191 help
1192 SLUB has extensive debug support features. Disabling these can
1193 result in significant savings in code size. This also disables
1194 SLUB sysfs support. /sys/slab will not exist and there will be
1195 no support for cache validation etc.
1196
Randy Dunlapb943c462009-03-10 12:55:46 -07001197config COMPAT_BRK
1198 bool "Disable heap randomization"
1199 default y
1200 help
1201 Randomizing heap placement makes heap exploits harder, but it
1202 also breaks ancient binaries (including anything libc5 based).
1203 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001204 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001205 /proc/sys/kernel/randomize_va_space to 2.
1206
1207 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1208
Christoph Lameter81819f02007-05-06 14:49:36 -07001209choice
1210 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001211 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001212 help
1213 This option allows to select a slab allocator.
1214
1215config SLAB
1216 bool "SLAB"
1217 help
1218 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001219 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001220 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001221
1222config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001223 bool "SLUB (Unqueued Allocator)"
1224 help
1225 SLUB is a slab allocator that minimizes cache line usage
1226 instead of managing queues of cached objects (SLAB approach).
1227 Per cpu caching is realized using slabs of objects instead
1228 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001229 and has enhanced diagnostics. SLUB is the default choice for
1230 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001231
1232config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001233 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001234 bool "SLOB (Simple Allocator)"
1235 help
Matt Mackall37291452008-02-04 22:29:38 -08001236 SLOB replaces the stock allocator with a drastically simpler
1237 allocator. SLOB is generally more space efficient but
1238 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001239
1240endchoice
1241
Jie Zhangea637632009-12-14 18:00:02 -08001242config MMAP_ALLOW_UNINITIALIZED
1243 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001244 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001245 default n
1246 help
1247 Normally, and according to the Linux spec, anonymous memory obtained
1248 from mmap() has it's contents cleared before it is passed to
1249 userspace. Enabling this config option allows you to request that
1250 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1251 providing a huge performance boost. If this option is not enabled,
1252 then the flag will be ignored.
1253
1254 This is taken advantage of by uClibc's malloc(), and also by
1255 ELF-FDPIC binfmt's brk and stack allocator.
1256
1257 Because of the obvious security issues, this option should only be
1258 enabled on embedded devices where you control what is run in
1259 userspace. Since that isn't generally a problem on no-MMU systems,
1260 it is normally safe to say Y here.
1261
1262 See Documentation/nommu-mmap.txt for more information.
1263
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001264config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001265 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001266 help
1267 Say Y here to enable the extended profiling support mechanisms used
1268 by profilers such as OProfile.
1269
Ingo Molnar5f87f112008-07-23 14:15:22 +02001270#
1271# Place an empty function call at each tracepoint site. Can be
1272# dynamically changed for a probe function.
1273#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001274config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001275 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001276
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001277source "arch/Kconfig"
1278
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279endmenu # General setup
1280
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001281config HAVE_GENERIC_DMA_COHERENT
1282 bool
1283 default n
1284
Linus Torvalds158a9622008-01-02 13:04:48 -08001285config SLABINFO
1286 bool
1287 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001288 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001289 default y
1290
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001291config RT_MUTEXES
1292 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001293
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294config BASE_SMALL
1295 int
1296 default 0 if BASE_FULL
1297 default 1 if !BASE_FULL
1298
Jan Engelhardt66da5732007-07-15 23:39:29 -07001299menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 bool "Enable loadable module support"
1301 help
1302 Kernel modules are small pieces of compiled code which can
1303 be inserted in the running kernel, rather than being
1304 permanently built into the kernel. You use the "modprobe"
1305 tool to add (and sometimes remove) them. If you say Y here,
1306 many parts of the kernel can be built as modules (by
1307 answering M instead of Y where indicated): this is most
1308 useful for infrequently used options which are not required
1309 for booting. For more information, see the man pages for
1310 modprobe, lsmod, modinfo, insmod and rmmod.
1311
1312 If you say Y here, you will need to run "make
1313 modules_install" to put the modules under /lib/modules/
1314 where modprobe can find them (you may need to be root to do
1315 this).
1316
1317 If unsure, say Y.
1318
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001319if MODULES
1320
Linus Torvalds826e4502008-05-04 17:04:16 -07001321config MODULE_FORCE_LOAD
1322 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001323 default n
1324 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001325 Allow loading of modules without version information (ie. modprobe
1326 --force). Forced module loading sets the 'F' (forced) taint flag and
1327 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001328
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329config MODULE_UNLOAD
1330 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 help
1332 Without this option you will not be able to unload any
1333 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001334 anyway), which makes your kernel smaller, faster
1335 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
1337config MODULE_FORCE_UNLOAD
1338 bool "Forced module unloading"
1339 depends on MODULE_UNLOAD && EXPERIMENTAL
1340 help
1341 This option allows you to force a module to unload, even if the
1342 kernel believes it is unsafe: the kernel will remove the module
1343 without waiting for anyone to stop using it (using the -f option to
1344 rmmod). This is mainly for kernel developers and desperate users.
1345 If unsure, say N.
1346
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001348 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 help
1350 Usually, you have to use modules compiled with your kernel.
1351 Saying Y here makes it sometimes possible to use modules
1352 compiled for different kernels, by adding enough information
1353 to the modules to (hopefully) spot any changes which would
1354 make them incompatible with the kernel you are running. If
1355 unsure, say N.
1356
1357config MODULE_SRCVERSION_ALL
1358 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 help
1360 Modules which contain a MODULE_VERSION get an extra "srcversion"
1361 field inserted into their modinfo section, which contains a
1362 sum of the source files which made it. This helps maintainers
1363 see exactly which source was used to build a module (since
1364 others sometimes change the module source without updating
1365 the version). With this option, such a "srcversion" field
1366 will be created for all modules. If unsure, say N.
1367
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001368endif # MODULES
1369
Rusty Russell98a79d62008-12-13 21:19:41 +10301370config INIT_ALL_POSSIBLE
1371 bool
1372 help
1373 Back when each arch used to define their own cpu_online_map and
1374 cpu_possible_map, some of them chose to initialize cpu_possible_map
1375 with all 1s, and others with all 0s. When they were centralised,
1376 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001377 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301378
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379config STOP_MACHINE
1380 bool
1381 default y
1382 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1383 help
1384 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001385
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001386source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001387
1388config PREEMPT_NOTIFIERS
1389 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001390
Steffen Klassert16295be2010-01-06 19:47:10 +11001391config PADATA
1392 depends on SMP
1393 bool
1394
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001395source "kernel/Kconfig.locks"