blob: 412c21b00d513f81269d7860b1a9af1909e0225f [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
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
Al Boldiff0cfc62007-07-31 00:39:23 -070030menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32config EXPERIMENTAL
33 bool "Prompt for development and/or incomplete code/drivers"
34 ---help---
35 Some of the various things that Linux supports (such as network
36 drivers, file systems, network protocols, etc.) can be in a state
37 of development where the functionality, stability, or the level of
38 testing is not yet high enough for general use. This is usually
39 known as the "alpha-test" phase among developers. If a feature is
40 currently in alpha-test, then the developers usually discourage
41 uninformed widespread use of this feature by the general public to
42 avoid "Why doesn't this work?" type mail messages. However, active
43 testing and use of these systems is welcomed. Just be aware that it
44 may not meet the normal level of reliability or it may fail to work
45 in some special cases. Detailed bug reports from people familiar
46 with the kernel internals are usually welcomed by the developers
47 (before submitting bug reports, please read the documents
48 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
49 <file:Documentation/BUG-HUNTING>, and
50 <file:Documentation/oops-tracing.txt> in the kernel source).
51
52 This option will also make obsoleted drivers available. These are
53 drivers that have been replaced by something else, and/or are
54 scheduled to be removed in a future kernel release.
55
56 Unless you intend to help test and develop a feature or driver that
57 falls into this category, or you have a situation that requires
58 using these features, you should probably say N here, which will
59 cause the configurator to present you with fewer choices. If
60 you say Y here, you will be offered the choice of using features or
61 drivers that are currently considered to be in the alpha-test phase.
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063config BROKEN
64 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66config BROKEN_ON_SMP
67 bool
68 depends on BROKEN || !SMP
69 default y
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071config INIT_ENV_ARG_LIMIT
72 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070073 default 32 if !UML
74 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080076 Maximum of each of the number of arguments and environment
77 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Roland McGrath84336462009-12-21 16:24:06 -080080config CROSS_COMPILE
81 string "Cross-compiler tool prefix"
82 help
83 Same as running 'make CROSS_COMPILE=prefix-' but stored for
84 default make runs in this kernel build directory. You don't
85 need to set this unless you want the configured kernel build
86 directory to select the cross-compiler automatically.
87
Linus Torvalds1da177e2005-04-16 15:20:36 -070088config LOCALVERSION
89 string "Local version - append to kernel release"
90 help
91 Append an extra string to the end of your kernel version.
92 This will show up when you type uname, for example.
93 The string you set here will be appended after the contents of
94 any files with a filename matching localversion* in your
95 object and source tree, in that order. Your total string can
96 be a maximum of 64 characters.
97
Ryan Andersonaaebf432005-07-31 04:57:49 -040098config LOCALVERSION_AUTO
99 bool "Automatically append version information to the version string"
100 default y
101 help
102 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200103 release tree by looking for git tags that belong to the current
104 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400105
106 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200107 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200109 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400110
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200111 (The actual string used here is the first eight characters produced
112 by running the command:
113
114 $ git rev-parse --verify HEAD
115
116 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400117
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800118config HAVE_KERNEL_GZIP
119 bool
120
121config HAVE_KERNEL_BZIP2
122 bool
123
124config HAVE_KERNEL_LZMA
125 bool
126
Lasse Collin3ebe1242011-01-12 17:01:23 -0800127config HAVE_KERNEL_XZ
128 bool
129
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800130config HAVE_KERNEL_LZO
131 bool
132
Alain Knaff30d65db2009-01-04 22:46:17 +0100133choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800134 prompt "Kernel compression mode"
135 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800136 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 -0800137 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100138 The linux kernel is a kind of self-extracting executable.
139 Several compression algorithms are available, which differ
140 in efficiency, compression and decompression speed.
141 Compression speed is only relevant when building a kernel.
142 Decompression speed is relevant at each boot.
143
144 If you have any problems with bzip2 or lzma compressed
145 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
146 version of this functionality (bzip2 only), for 2.4, was
147 supplied by Christian Ludwig)
148
149 High compression options are mostly useful for users, who
150 are low on disk space (embedded systems), but for whom ram
151 size matters less.
152
153 If in doubt, select 'gzip'
154
155config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800156 bool "Gzip"
157 depends on HAVE_KERNEL_GZIP
158 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800159 The old and tried gzip compression. It provides a good balance
160 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
162config KERNEL_BZIP2
163 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800164 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100165 help
166 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 Decompression speed is slowest among the three. The kernel
168 size is about 10% smaller with bzip2, in comparison to gzip.
169 Bzip2 uses a large amount of memory. For modern kernels you
170 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100171
172config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800173 bool "LZMA"
174 depends on HAVE_KERNEL_LZMA
175 help
176 The most recent compression algorithm.
177 Its ratio is best, decompression speed is between the other
178 two. Compression is slowest. The kernel size is about 33%
179 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100180
Lasse Collin3ebe1242011-01-12 17:01:23 -0800181config KERNEL_XZ
182 bool "XZ"
183 depends on HAVE_KERNEL_XZ
184 help
185 XZ uses the LZMA2 algorithm and instruction set specific
186 BCJ filters which can improve compression ratio of executable
187 code. The size of the kernel is about 30% smaller with XZ in
188 comparison to gzip. On architectures for which there is a BCJ
189 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
190 will create a few percent smaller kernel than plain LZMA.
191
192 The speed is about the same as with LZMA: The decompression
193 speed of XZ is better than that of bzip2 but worse than gzip
194 and LZO. Compression is slow.
195
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800196config KERNEL_LZO
197 bool "LZO"
198 depends on HAVE_KERNEL_LZO
199 help
200 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200201 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800202 (both compression and decompression) is the fastest.
203
Alain Knaff30d65db2009-01-04 22:46:17 +0100204endchoice
205
Josh Triplettbd5dc172011-06-15 15:08:28 -0700206config DEFAULT_HOSTNAME
207 string "Default hostname"
208 default "(none)"
209 help
210 This option determines the default system hostname before userspace
211 calls sethostname(2). The kernel traditionally uses "(none)" here,
212 but you may wish to use a different default here to make a minimal
213 system more usable with less configuration.
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215config SWAP
216 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200217 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 default y
219 help
220 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100221 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 used to provide more virtual memory than the actual RAM present
223 in your computer. If unsure say Y.
224
225config SYSVIPC
226 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 ---help---
228 Inter Process Communication is a suite of library functions and
229 system calls which let processes (running programs) synchronize and
230 exchange information. It is generally considered to be a good thing,
231 and some programs won't run unless you say Y here. In particular, if
232 you want to run the DOS emulator dosemu under Linux (read the
233 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
234 you'll need to say Y here.
235
236 You can find documentation about IPC with "info ipc" and also in
237 section 6.4 of the Linux Programmer's Guide, available from
238 <http://www.tldp.org/guides.html>.
239
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800240config SYSVIPC_SYSCTL
241 bool
242 depends on SYSVIPC
243 depends on SYSCTL
244 default y
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246config POSIX_MQUEUE
247 bool "POSIX Message Queues"
248 depends on NET && EXPERIMENTAL
249 ---help---
250 POSIX variant of message queues is a part of IPC. In POSIX message
251 queues every message has a priority which decides about succession
252 of receiving it by a process. If you want to compile and run
253 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200254 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 POSIX message queues are visible as a filesystem called 'mqueue'
257 and can be mounted somewhere if you want to do filesystem
258 operations on message queues.
259
260 If unsure, say Y.
261
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700262config POSIX_MQUEUE_SYSCTL
263 bool
264 depends on POSIX_MQUEUE
265 depends on SYSCTL
266 default y
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268config BSD_PROCESS_ACCT
269 bool "BSD Process Accounting"
270 help
271 If you say Y here, a user level program will be able to instruct the
272 kernel (via a special system call) to write process accounting
273 information to a file: whenever a process exits, information about
274 that process will be appended to the file by the kernel. The
275 information includes things such as creation time, owning user,
276 command name, memory usage, controlling terminal etc. (the complete
277 list is in the struct acct in <file:include/linux/acct.h>). It is
278 up to the user level program to do useful things with this
279 information. This is generally a good idea, so say Y.
280
281config BSD_PROCESS_ACCT_V3
282 bool "BSD Process Accounting version 3 file format"
283 depends on BSD_PROCESS_ACCT
284 default n
285 help
286 If you say Y here, the process accounting information is written
287 in a new file format that also logs the process IDs of each
288 process and it's parent. Note that this file format is incompatible
289 with previous v0/v1/v2 file formats, so you will need updated tools
290 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300291 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530293config FHANDLE
294 bool "open by fhandle syscalls"
295 select EXPORTFS
296 help
297 If you say Y here, a user level program will be able to map
298 file names to handle and then later use the handle for
299 different file system operations. This is useful in implementing
300 userspace file servers, which now track files using handles instead
301 of names. The handle would remain the same even if file names
302 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
303 syscalls.
304
Shailabh Nagarc7572492006-07-14 00:24:40 -0700305config TASKSTATS
306 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
307 depends on NET
308 default n
309 help
310 Export selected statistics for tasks/processes through the
311 generic netlink interface. Unlike BSD process accounting, the
312 statistics are available during the lifetime of tasks/processes as
313 responses to commands. Like BSD accounting, they are sent to user
314 space on task exit.
315
316 Say N if unsure.
317
Shailabh Nagarca74e922006-07-14 00:24:36 -0700318config TASK_DELAY_ACCT
319 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700320 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700321 help
322 Collect information on time spent by a task waiting for system
323 resources like cpu, synchronous block I/O completion and swapping
324 in pages. Such statistics can help in setting a task's priorities
325 relative to other tasks for cpu, io, rss limits etc.
326
327 Say N if unsure.
328
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800329config TASK_XACCT
330 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
331 depends on TASKSTATS
332 help
333 Collect extended task accounting data and send the data
334 to userland for processing over the taskstats interface.
335
336 Say N if unsure.
337
338config TASK_IO_ACCOUNTING
339 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
340 depends on TASK_XACCT
341 help
342 Collect information on the number of bytes of storage I/O which this
343 task has caused.
344
345 Say N if unsure.
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347config AUDIT
348 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100349 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 help
351 Enable auditing infrastructure that can be used with another
352 kernel subsystem, such as SELinux (which requires this for
353 logging of avc messages output). Does not do system-call
354 auditing without CONFIG_AUDITSYSCALL.
355
356config AUDITSYSCALL
357 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000358 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 default y if SECURITY_SELINUX
360 help
361 Enable low-overhead system-call auditing infrastructure that
362 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500363 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Eric Paris939a67f2009-12-17 20:12:06 -0500365config AUDIT_WATCH
366 def_bool y
367 depends on AUDITSYSCALL
368 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Al Viro74c3cbe2007-07-22 08:04:18 -0400370config AUDIT_TREE
371 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400372 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500373 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400374
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000375source "kernel/irq/Kconfig"
376
Mike Travisc903ff82009-01-15 12:28:29 -0800377menu "RCU Subsystem"
378
379choice
380 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700381 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800382
Mike Travisc903ff82009-01-15 12:28:29 -0800383config TREE_RCU
384 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700385 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800386 help
387 This option selects the RCU implementation that is
388 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700389 thousands of CPUs. It also scales down nicely to
390 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800391
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700392config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700393 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700394 depends on PREEMPT
395 help
396 This option selects the RCU implementation that is
397 designed for very large SMP systems with hundreds or
398 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700399 is also required. It also scales down nicely to
400 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700401
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700402config TINY_RCU
403 bool "UP-only small-memory-footprint RCU"
404 depends on !SMP
405 help
406 This option selects the RCU implementation that is
407 designed for UP systems from which real-time response
408 is not required. This option greatly reduces the
409 memory footprint of RCU.
410
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700411config TINY_PREEMPT_RCU
412 bool "Preemptible UP-only small-memory-footprint RCU"
413 depends on !SMP && PREEMPT
414 help
415 This option selects the RCU implementation that is designed
416 for real-time UP systems. This option greatly reduces the
417 memory footprint of RCU.
418
Mike Travisc903ff82009-01-15 12:28:29 -0800419endchoice
420
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700421config PREEMPT_RCU
422 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
423 help
424 This option enables preemptible-RCU code that is common between
425 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
426
Mike Travisc903ff82009-01-15 12:28:29 -0800427config RCU_TRACE
428 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800429 help
430 This option provides tracing in RCU which presents stats
431 in debugfs for debugging RCU implementation.
432
433 Say Y here if you want to enable RCU tracing
434 Say N if you are unsure.
435
436config RCU_FANOUT
437 int "Tree-based hierarchical RCU fanout value"
438 range 2 64 if 64BIT
439 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700440 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800441 default 64 if 64BIT
442 default 32 if !64BIT
443 help
444 This option controls the fanout of hierarchical implementations
445 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700446 large numbers of CPUs. This value must be at least the fourth
447 root of NR_CPUS, which allows NR_CPUS to be insanely large.
448 The default value of RCU_FANOUT should be used for production
449 systems, but if you are stress-testing the RCU implementation
450 itself, small RCU_FANOUT values allow you to test large-system
451 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800452
453 Select a specific number if testing RCU itself.
454 Take the default if unsure.
455
456config RCU_FANOUT_EXACT
457 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700458 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800459 default n
460 help
461 This option forces use of the exact RCU_FANOUT value specified,
462 regardless of imbalances in the hierarchy. This is useful for
463 testing RCU itself, and might one day be useful on systems with
464 strong NUMA behavior.
465
466 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
467
468 Say N if unsure.
469
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800470config RCU_FAST_NO_HZ
471 bool "Accelerate last non-dyntick-idle CPU's grace periods"
472 depends on TREE_RCU && NO_HZ && SMP
473 default n
474 help
475 This option causes RCU to attempt to accelerate grace periods
476 in order to allow the final CPU to enter dynticks-idle state
477 more quickly. On the other hand, this option increases the
478 overhead of the dynticks-idle checking, particularly on systems
479 with large numbers of CPUs.
480
481 Say Y if energy efficiency is critically important, particularly
482 if you have relatively few CPUs.
483
484 Say N if you are unsure.
485
Mike Travisc903ff82009-01-15 12:28:29 -0800486config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700487 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800488 select DEBUG_FS
489 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700490 This option provides tracing for the TREE_RCU and
491 TREE_PREEMPT_RCU implementations, permitting Makefile to
492 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800493
Paul E. McKenney24278d12010-09-27 17:25:23 -0700494config RCU_BOOST
495 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800496 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700497 default n
498 help
499 This option boosts the priority of preempted RCU readers that
500 block the current preemptible RCU grace period for too long.
501 This option also prevents heavy loads from blocking RCU
502 callback invocation for all flavors of RCU.
503
504 Say Y here if you are working with real-time apps or heavy loads
505 Say N here if you are unsure.
506
507config RCU_BOOST_PRIO
508 int "Real-time priority to boost RCU readers to"
509 range 1 99
510 depends on RCU_BOOST
511 default 1
512 help
513 This option specifies the real-time priority to which preempted
514 RCU readers are to be boosted. If you are working with CPU-bound
515 real-time applications, you should specify a priority higher then
516 the highest-priority CPU-bound application.
517
518 Specify the real-time priority, or take the default if unsure.
519
520config RCU_BOOST_DELAY
521 int "Milliseconds to delay boosting after RCU grace-period start"
522 range 0 3000
523 depends on RCU_BOOST
524 default 500
525 help
526 This option specifies the time to wait after the beginning of
527 a given grace period before priority-boosting preempted RCU
528 readers blocking that grace period. Note that any RCU reader
529 blocking an expedited RCU grace period is boosted immediately.
530
531 Accept the default if unsure.
532
Mike Travisc903ff82009-01-15 12:28:29 -0800533endmenu # "RCU Subsystem"
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700536 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 ---help---
538 This option enables the complete Linux kernel ".config" file
539 contents to be saved in the kernel. It provides documentation
540 of which kernel options are used in a running kernel or in an
541 on-disk kernel. This information can be extracted from the kernel
542 image file with the script scripts/extract-ikconfig and used as
543 input to rebuild the current kernel or to build another kernel.
544 It can also be extracted from a running kernel by reading
545 /proc/config.gz if enabled (below).
546
547config IKCONFIG_PROC
548 bool "Enable access to .config through /proc/config.gz"
549 depends on IKCONFIG && PROC_FS
550 ---help---
551 This option enables access to the kernel configuration file
552 through /proc/config.gz.
553
Alistair John Strachan794543a2007-05-08 00:31:15 -0700554config LOG_BUF_SHIFT
555 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
556 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700557 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700558 help
559 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700560 Examples:
561 17 => 128 KB
562 16 => 64 KB
563 15 => 32 KB
564 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700565 13 => 8 KB
566 12 => 4 KB
567
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800568#
569# Architectures with an unreliable sched_clock() should select this:
570#
571config HAVE_UNSTABLE_SCHED_CLOCK
572 bool
573
Li Zefan23964d22009-01-15 13:50:58 -0800574menuconfig CGROUPS
575 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800576 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700577 help
Li Zefan23964d22009-01-15 13:50:58 -0800578 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800579 use with process control subsystems such as Cpusets, CFS, memory
580 controls or device isolation.
581 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800582 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800583 - Documentation/cgroups/ (features for grouping, isolation
584 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700585
586 Say N if unsure.
587
Li Zefan23964d22009-01-15 13:50:58 -0800588if CGROUPS
589
Paul Menage006cb992007-10-18 23:39:43 -0700590config CGROUP_DEBUG
591 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700592 default n
Paul Menage006cb992007-10-18 23:39:43 -0700593 help
594 This option enables a simple cgroup subsystem that
595 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800596 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700597
Li Zefan23964d22009-01-15 13:50:58 -0800598 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700599
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700600config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800601 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800602 help
603 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700604 cgroup.
605
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700606config CGROUP_DEVICE
607 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700608 help
609 Provides a cgroup implementing whitelists for devices which
610 a process in the cgroup can mknod or open.
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612config CPUSETS
613 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700615 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 allow dynamically partitioning a system into sets of CPUs and
617 Memory Nodes and assigning tasks to run only within those sets.
618 This is primarily useful on large SMP or NUMA systems.
619
620 Say N if unsure.
621
Li Zefan23964d22009-01-15 13:50:58 -0800622config PROC_PID_CPUSET
623 bool "Include legacy /proc/<pid>/cpuset file"
624 depends on CPUSETS
625 default y
626
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100627config CGROUP_CPUACCT
628 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100629 help
630 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800631 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100632
Pavel Emelianove552b662008-02-07 00:13:49 -0800633config RESOURCE_COUNTERS
634 bool "Resource counters"
635 help
636 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800637 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800638
Balbir Singh00f0b822008-03-04 14:28:39 -0800639config CGROUP_MEM_RES_CTLR
640 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700641 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700642 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800643 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700644 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100645 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800646
647 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700648 associated with each page of memory in the system. By this,
649 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
650 usage tracking struct at boot. Total amount of this is printed out
651 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800652
653 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700654 sure you need the memory resource controller. Even when you enable
655 this, you can set "cgroup_disable=memory" at your boot option to
656 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800657 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800658
Balbir Singhcf475ad2008-04-29 01:00:16 -0700659 This config option also selects MM_OWNER config option, which
660 could in turn add some fork/exit overhead.
661
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800662config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700663 bool "Memory Resource Controller Swap Extension"
664 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800665 help
666 Add swap management feature to memory resource controller. When you
667 enable this, you can limit mem+swap usage per cgroup. In other words,
668 when you disable this, memory resource controller has no cares to
669 usage of swap...a process can exhaust all of the swap. This extension
670 is useful when you want to avoid exhaustion swap but this itself
671 adds more overheads and consumes memory for remembering information.
672 Especially if you use 32bit system or small memory system, please
673 be careful about enabling this. When memory resource controller
674 is disabled by boot option, this will be automatically disabled and
675 there will be no overhead from this. Even when you set this config=y,
676 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700677 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
678 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800679config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
680 bool "Memory Resource Controller Swap Extension enabled by default"
681 depends on CGROUP_MEM_RES_CTLR_SWAP
682 default y
683 help
684 Memory Resource Controller Swap Extension comes with its price in
685 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700686 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800687 and let the user enable it by swapaccount boot command line
688 parameter should have this option unselected.
689 For those who want to have the feature enabled by default should
690 select this option (if, for some reason, they need to disable it
691 then noswapaccount does the trick).
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800692
Stephane Eraniane5d13672011-02-14 11:20:01 +0200693config CGROUP_PERF
694 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
695 depends on PERF_EVENTS && CGROUPS
696 help
697 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800698 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200699 designated cpu.
700
701 Say N if unsure.
702
Dhaval Giani7c941432010-01-20 13:26:18 +0100703menuconfig CGROUP_SCHED
704 bool "Group CPU scheduler"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700705 depends on EXPERIMENTAL
Dhaval Giani7c941432010-01-20 13:26:18 +0100706 default n
707 help
708 This feature lets CPU scheduler recognize task groups and control CPU
709 bandwidth allocation to such task groups. It uses cgroups to group
710 tasks.
711
712if CGROUP_SCHED
713config FAIR_GROUP_SCHED
714 bool "Group scheduling for SCHED_OTHER"
715 depends on CGROUP_SCHED
716 default CGROUP_SCHED
717
718config RT_GROUP_SCHED
719 bool "Group scheduling for SCHED_RR/FIFO"
720 depends on EXPERIMENTAL
721 depends on CGROUP_SCHED
722 default n
723 help
724 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800725 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100726 schedule realtime tasks for non-root users until you allocate
727 realtime bandwidth for them.
728 See Documentation/scheduler/sched-rt-group.txt for more information.
729
730endif #CGROUP_SCHED
731
Vivek Goyalafc24d42010-04-26 19:27:56 +0200732config BLK_CGROUP
733 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700734 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200735 default n
736 ---help---
737 Generic block IO controller cgroup interface. This is the common
738 cgroup interface which should be used by various IO controlling
739 policies.
740
741 Currently, CFQ IO scheduler uses it to recognize task groups and
742 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400743 to such task groups. It is also used by bio throttling logic in
744 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200745
746 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400747 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000748 enabling proportional weight division of disk bandwidth in CFQ, set
749 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000750 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200751
752 See Documentation/cgroups/blkio-controller.txt for more information.
753
754config DEBUG_BLK_CGROUP
755 bool "Enable Block IO controller debugging"
756 depends on BLK_CGROUP
757 default n
758 ---help---
759 Enable some debugging help. Currently it exports additional stat
760 files in a cgroup which can be useful for debugging.
761
Li Zefan23964d22009-01-15 13:50:58 -0800762endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800763
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700764menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800765 bool "Namespaces support" if EXPERT
766 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800767 help
768 Provides the way to make tasks work with different objects using
769 the same id. For example same IPC id may refer to different objects
770 or same user id or pid may refer to different tasks when used in
771 different namespaces.
772
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700773if NAMESPACES
774
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800775config UTS_NS
776 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700777 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800778 help
779 In this namespace tasks see different info provided with the
780 uname() system call
781
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800782config IPC_NS
783 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700784 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700785 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800786 help
787 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700788 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800789
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800790config USER_NS
791 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700792 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700793 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800794 help
795 This allows containers, i.e. vservers, to use user namespaces
796 to provide different user info for different servers.
797 If unsure, say N.
798
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800799config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700800 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700801 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800802 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300803 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100804 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800805 pid namespaces. This is a building block of containers.
806
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800807config NET_NS
808 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700809 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700810 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800811 help
812 Allow user space to create what appear to be multiple instances
813 of the network stack.
814
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700815endif # NAMESPACES
816
Mike Galbraith5091faa2010-11-30 14:18:03 +0100817config SCHED_AUTOGROUP
818 bool "Automatic process group scheduling"
819 select EVENTFD
820 select CGROUPS
821 select CGROUP_SCHED
822 select FAIR_GROUP_SCHED
823 help
824 This option optimizes the scheduler for common desktop workloads by
825 automatically creating and populating task groups. This separation
826 of workloads isolates aggressive CPU burners (like build jobs) from
827 desktop applications. Task group autogeneration is currently based
828 upon task session.
829
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700830config MM_OWNER
831 bool
832
833config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100834 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700835 depends on SYSFS
836 default n
837 help
838 This option adds code that switches the layout of the "block" class
839 devices, to not show up in /sys/class/block/, but only in
840 /sys/block/.
841
842 This switch is only active when the sysfs.deprecated=1 boot option is
843 passed or the SYSFS_DEPRECATED_V2 option is set.
844
845 This option allows new kernels to run on old distributions and tools,
846 which might get confused by /sys/class/block/. Since 2007/2008 all
847 major distributions and tools handle this just fine.
848
849 Recent distributions and userspace tools after 2009/2010 depend on
850 the existence of /sys/class/block/, and will not work with this
851 option enabled.
852
853 Only if you are using a new kernel on an old distribution, you might
854 need to say Y here.
855
856config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100857 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700858 default n
859 depends on SYSFS
860 depends on SYSFS_DEPRECATED
861 help
862 Enable deprecated sysfs by default.
863
864 See the CONFIG_SYSFS_DEPRECATED option for more details about this
865 option.
866
867 Only if you are using a new kernel on an old distribution, you might
868 need to say Y here. Even then, odds are you would not need it
869 enabled, you can always pass the boot option if absolutely necessary.
870
871config RELAY
872 bool "Kernel->user space relay support (formerly relayfs)"
873 help
874 This option enables support for relay interface support in
875 certain file systems (such as debugfs).
876 It is designed to provide an efficient mechanism for tools and
877 facilities to relay large amounts of data from kernel space to
878 user space.
879
880 If unsure, say N.
881
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800882config BLK_DEV_INITRD
883 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
884 depends on BROKEN || !FRV
885 help
886 The initial RAM filesystem is a ramfs which is loaded by the
887 boot loader (loadlin or lilo) and that is mounted as root
888 before the normal boot procedure. It is typically used to
889 load modules needed to mount the "real" root file system,
890 etc. See <file:Documentation/initrd.txt> for details.
891
892 If RAM disk support (BLK_DEV_RAM) is also included, this
893 also enables initial RAM disk (initrd) support and adds
894 15 Kbytes (more on some other architectures) to the kernel size.
895
896 If unsure say Y.
897
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800898if BLK_DEV_INITRD
899
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200900source "usr/Kconfig"
901
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800902endif
903
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800904config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200905 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800906 help
907 Enabling this option will pass "-Os" instead of "-O2" to gcc
908 resulting in a smaller kernel.
909
jkacur775a7222008-07-16 00:31:16 +0200910 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800911
Randy Dunlap08470622006-09-30 23:28:13 -0700912config SYSCTL
913 bool
914
Randy Dunlapb943c462009-03-10 12:55:46 -0700915config ANON_INODES
916 bool
917
David Rientjes6a108a12011-01-20 14:44:16 -0800918menuconfig EXPERT
919 bool "Configure standard kernel features (expert users)"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 help
921 This option allows certain base kernel options and settings
922 to be disabled or tweaked. This is for specialized
923 environments which can tolerate a "non-standard" kernel.
924 Only use this if you really know what you are doing.
925
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700926config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800927 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700928 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 -0700929 default y
930 help
931 This enables the legacy 16-bit UID syscall wrappers.
932
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700933config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800934 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800935 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800936 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700937 select SYSCTL
938 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800939 sys_sysctl uses binary paths that have been found challenging
940 to properly maintain and use. The interface in /proc/sys
941 using paths with ascii names is now the primary path to this
942 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700943
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800944 Almost nothing using the binary sysctl interface so if you are
945 trying to save some space it is probably safe to disable this,
946 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700947
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800948 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800951 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 default y
953 help
954 Say Y here to let the kernel print out symbolic crash information and
955 symbolic stack backtraces. This increases the size of the kernel
956 somewhat, as all symbols have to be loaded into the kernel image.
957
958config KALLSYMS_ALL
959 bool "Include all symbols in kallsyms"
960 depends on DEBUG_KERNEL && KALLSYMS
961 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300962 Normally kallsyms only contains the symbols of functions for nicer
963 OOPS messages and backtraces (i.e., symbols from the text and inittext
964 sections). This is sufficient for most cases. And only in very rare
965 cases (e.g., when a debugger is used) all symbols are required (e.g.,
966 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300968 This option makes sure that all symbols are loaded into the kernel
969 image (i.e., symbols from all sections) in cost of increased kernel
970 size (depending on the kernel configuration, it may be 300KiB or
971 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300973 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -0700974
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800975config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -0800976 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800977 default y
978 help
979 This option is provided for the case where no hotplug or uevent
980 capabilities is wanted by the kernel. You should only consider
981 disabling this option for embedded systems that do not use modules, a
982 dynamic /dev tree, or dynamic device discovery. Just say Y.
983
Matt Mackalld59745c2005-05-01 08:59:02 -0700984config PRINTK
985 default y
David Rientjes6a108a12011-01-20 14:44:16 -0800986 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -0700987 help
988 This option enables normal printk support. Removing it
989 eliminates most of the message strings from the kernel image
990 and makes the kernel more or less silent. As this makes it
991 very difficult to diagnose system problems, saying N here is
992 strongly discouraged.
993
Matt Mackallc8538a72005-05-01 08:59:01 -0700994config BUG
David Rientjes6a108a12011-01-20 14:44:16 -0800995 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -0700996 default y
997 help
998 Disabling this option eliminates support for BUG and WARN, reducing
999 the size of your kernel image and potentially quietly ignoring
1000 numerous fatal conditions. You should only consider disabling this
1001 option for embedded systems with no facilities for reporting errors.
1002 Just say Y.
1003
Matt Mackall708e9a72006-01-08 01:05:25 -08001004config ELF_CORE
1005 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001006 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001007 help
1008 Enable support for generating core dumps. Disabling saves about 4k.
1009
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001010config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001011 bool "Enable PC-Speaker support" if EXPERT
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001012 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
1013 default y
1014 help
1015 This option allows to disable the internal PC-Speaker
1016 support, saving some memory.
1017
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018config BASE_FULL
1019 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001020 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 help
1022 Disabling this option reduces the size of miscellaneous core
1023 kernel data structures. This saves memory on small machines,
1024 but may reduce performance.
1025
1026config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001027 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -07001029 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 help
1031 Disabling this option will cause the kernel to be built without
1032 support for "fast userspace mutexes". The resulting kernel may not
1033 run glibc-based applications correctly.
1034
1035config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001036 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001038 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 help
1040 Disabling this option will cause the kernel to be built without
1041 support for epoll family of system calls.
1042
Davide Libenzifba2afa2007-05-10 22:23:13 -07001043config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001044 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001045 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001046 default y
1047 help
1048 Enable the signalfd() system call that allows to receive signals
1049 on a file descriptor.
1050
1051 If unsure, say Y.
1052
Davide Libenzib215e282007-05-10 22:23:16 -07001053config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001054 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001055 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001056 default y
1057 help
1058 Enable the timerfd() system call that allows to receive timer
1059 events on a file descriptor.
1060
1061 If unsure, say Y.
1062
Davide Libenzie1ad7462007-05-10 22:23:19 -07001063config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001064 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001065 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001066 default y
1067 help
1068 Enable the eventfd() system call that allows to receive both
1069 kernel notification (ie. KAIO) or userspace notifications.
1070
1071 If unsure, say Y.
1072
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001074 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 default y
1076 depends on MMU
1077 help
1078 The shmem is an internal filesystem used to manage shared memory.
1079 It is backed by swap and manages resource limits. It is also exported
1080 to userspace as tmpfs if TMPFS is enabled. Disabling this
1081 option replaces shmem and tmpfs with the much simpler ramfs code,
1082 which may be appropriate on small systems without swap.
1083
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001084config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001085 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001086 default y
1087 help
1088 This option enables POSIX asynchronous I/O which may by used
1089 by some high performance threaded applications. Disabling
1090 this option saves about 7k.
1091
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001092config EMBEDDED
1093 bool "Embedded system"
1094 select EXPERT
1095 help
1096 This option should be enabled if compiling the kernel for
1097 an embedded system so certain expert options are available
1098 for configuration.
1099
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001100config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001101 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001102 help
1103 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001104
Peter Zijlstra906010b2009-09-21 16:08:49 +02001105config PERF_USE_VMALLOC
1106 bool
1107 help
1108 See tools/perf/design.txt for details
1109
Ingo Molnar57c0c152009-09-21 12:20:38 +02001110menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001111
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001112config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001113 bool "Kernel performance events and counters"
1114 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001115 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001116 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001117 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001118 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001119 Enable kernel support for various performance events provided
1120 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001121
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001122 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001123 use of generic tracepoints.
1124
1125 Most modern CPUs support performance events via performance
1126 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001127 types of hw events: such as instructions executed, cachemisses
1128 suffered, or branches mis-predicted - without slowing down the
1129 kernel or applications. These registers can also trigger interrupts
1130 when a threshold number of events have passed - and can thus be
1131 used to profile the code that runs on that CPU.
1132
Ingo Molnar57c0c152009-09-21 12:20:38 +02001133 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001134 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001135 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001136 provides per task and per CPU counters, and it provides event
1137 capabilities on top of those.
1138
1139 Say Y if unsure.
1140
Ingo Molnar57c0c152009-09-21 12:20:38 +02001141config PERF_COUNTERS
1142 bool "Kernel performance counters (old config option)"
1143 depends on HAVE_PERF_EVENTS
1144 help
1145 This config has been obsoleted by the PERF_EVENTS
1146 config option - please see that one for details.
1147
1148 It has no effect on the kernel whether you enable
1149 it or not, it is a compatibility placeholder.
1150
1151 Say N if unsure.
1152
Peter Zijlstra906010b2009-09-21 16:08:49 +02001153config DEBUG_PERF_USE_VMALLOC
1154 default n
1155 bool "Debug: use vmalloc to back perf mmap() buffers"
1156 depends on PERF_EVENTS && DEBUG_KERNEL
1157 select PERF_USE_VMALLOC
1158 help
1159 Use vmalloc memory to back perf mmap() buffers.
1160
1161 Mostly useful for debugging the vmalloc code on platforms
1162 that don't require it.
1163
1164 Say N if unsure.
1165
Thomas Gleixner0793a612008-12-04 20:12:29 +01001166endmenu
1167
Christoph Lameterf8891e52006-06-30 01:55:45 -07001168config VM_EVENT_COUNTERS
1169 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001170 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001171 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001172 VM event counters are needed for event counts to be shown.
1173 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001174 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001175 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001176
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001177config PCI_QUIRKS
1178 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001179 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001180 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001181 help
1182 This enables workarounds for various PCI chipset
1183 bugs/quirks. Disable this only if your target machine is
1184 unaffected by PCI quirks.
1185
Christoph Lameter41ecc552007-05-09 02:32:44 -07001186config SLUB_DEBUG
1187 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001188 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001189 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001190 help
1191 SLUB has extensive debug support features. Disabling these can
1192 result in significant savings in code size. This also disables
1193 SLUB sysfs support. /sys/slab will not exist and there will be
1194 no support for cache validation etc.
1195
Randy Dunlapb943c462009-03-10 12:55:46 -07001196config COMPAT_BRK
1197 bool "Disable heap randomization"
1198 default y
1199 help
1200 Randomizing heap placement makes heap exploits harder, but it
1201 also breaks ancient binaries (including anything libc5 based).
1202 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001203 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001204 /proc/sys/kernel/randomize_va_space to 2.
1205
1206 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1207
Christoph Lameter81819f02007-05-06 14:49:36 -07001208choice
1209 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001210 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001211 help
1212 This option allows to select a slab allocator.
1213
1214config SLAB
1215 bool "SLAB"
1216 help
1217 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001218 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001219 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001220
1221config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001222 bool "SLUB (Unqueued Allocator)"
1223 help
1224 SLUB is a slab allocator that minimizes cache line usage
1225 instead of managing queues of cached objects (SLAB approach).
1226 Per cpu caching is realized using slabs of objects instead
1227 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001228 and has enhanced diagnostics. SLUB is the default choice for
1229 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001230
1231config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001232 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001233 bool "SLOB (Simple Allocator)"
1234 help
Matt Mackall37291452008-02-04 22:29:38 -08001235 SLOB replaces the stock allocator with a drastically simpler
1236 allocator. SLOB is generally more space efficient but
1237 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001238
1239endchoice
1240
Jie Zhangea637632009-12-14 18:00:02 -08001241config MMAP_ALLOW_UNINITIALIZED
1242 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001243 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001244 default n
1245 help
1246 Normally, and according to the Linux spec, anonymous memory obtained
1247 from mmap() has it's contents cleared before it is passed to
1248 userspace. Enabling this config option allows you to request that
1249 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1250 providing a huge performance boost. If this option is not enabled,
1251 then the flag will be ignored.
1252
1253 This is taken advantage of by uClibc's malloc(), and also by
1254 ELF-FDPIC binfmt's brk and stack allocator.
1255
1256 Because of the obvious security issues, this option should only be
1257 enabled on embedded devices where you control what is run in
1258 userspace. Since that isn't generally a problem on no-MMU systems,
1259 it is normally safe to say Y here.
1260
1261 See Documentation/nommu-mmap.txt for more information.
1262
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001263config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001264 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001265 help
1266 Say Y here to enable the extended profiling support mechanisms used
1267 by profilers such as OProfile.
1268
Ingo Molnar5f87f112008-07-23 14:15:22 +02001269#
1270# Place an empty function call at each tracepoint site. Can be
1271# dynamically changed for a probe function.
1272#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001273config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001274 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001275
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001276source "arch/Kconfig"
1277
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278endmenu # General setup
1279
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001280config HAVE_GENERIC_DMA_COHERENT
1281 bool
1282 default n
1283
Linus Torvalds158a9622008-01-02 13:04:48 -08001284config SLABINFO
1285 bool
1286 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001287 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001288 default y
1289
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001290config RT_MUTEXES
1291 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001292
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293config BASE_SMALL
1294 int
1295 default 0 if BASE_FULL
1296 default 1 if !BASE_FULL
1297
Jan Engelhardt66da5732007-07-15 23:39:29 -07001298menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 bool "Enable loadable module support"
1300 help
1301 Kernel modules are small pieces of compiled code which can
1302 be inserted in the running kernel, rather than being
1303 permanently built into the kernel. You use the "modprobe"
1304 tool to add (and sometimes remove) them. If you say Y here,
1305 many parts of the kernel can be built as modules (by
1306 answering M instead of Y where indicated): this is most
1307 useful for infrequently used options which are not required
1308 for booting. For more information, see the man pages for
1309 modprobe, lsmod, modinfo, insmod and rmmod.
1310
1311 If you say Y here, you will need to run "make
1312 modules_install" to put the modules under /lib/modules/
1313 where modprobe can find them (you may need to be root to do
1314 this).
1315
1316 If unsure, say Y.
1317
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001318if MODULES
1319
Linus Torvalds826e4502008-05-04 17:04:16 -07001320config MODULE_FORCE_LOAD
1321 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001322 default n
1323 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001324 Allow loading of modules without version information (ie. modprobe
1325 --force). Forced module loading sets the 'F' (forced) taint flag and
1326 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001327
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328config MODULE_UNLOAD
1329 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 help
1331 Without this option you will not be able to unload any
1332 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001333 anyway), which makes your kernel smaller, faster
1334 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335
1336config MODULE_FORCE_UNLOAD
1337 bool "Forced module unloading"
1338 depends on MODULE_UNLOAD && EXPERIMENTAL
1339 help
1340 This option allows you to force a module to unload, even if the
1341 kernel believes it is unsafe: the kernel will remove the module
1342 without waiting for anyone to stop using it (using the -f option to
1343 rmmod). This is mainly for kernel developers and desperate users.
1344 If unsure, say N.
1345
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001347 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 help
1349 Usually, you have to use modules compiled with your kernel.
1350 Saying Y here makes it sometimes possible to use modules
1351 compiled for different kernels, by adding enough information
1352 to the modules to (hopefully) spot any changes which would
1353 make them incompatible with the kernel you are running. If
1354 unsure, say N.
1355
1356config MODULE_SRCVERSION_ALL
1357 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358 help
1359 Modules which contain a MODULE_VERSION get an extra "srcversion"
1360 field inserted into their modinfo section, which contains a
1361 sum of the source files which made it. This helps maintainers
1362 see exactly which source was used to build a module (since
1363 others sometimes change the module source without updating
1364 the version). With this option, such a "srcversion" field
1365 will be created for all modules. If unsure, say N.
1366
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001367endif # MODULES
1368
Rusty Russell98a79d62008-12-13 21:19:41 +10301369config INIT_ALL_POSSIBLE
1370 bool
1371 help
1372 Back when each arch used to define their own cpu_online_map and
1373 cpu_possible_map, some of them chose to initialize cpu_possible_map
1374 with all 1s, and others with all 0s. When they were centralised,
1375 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001376 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301377
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378config STOP_MACHINE
1379 bool
1380 default y
1381 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1382 help
1383 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001384
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001385source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001386
1387config PREEMPT_NOTIFIERS
1388 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001389
Steffen Klassert16295be2010-01-06 19:47:10 +11001390config PADATA
1391 depends on SMP
1392 bool
1393
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001394source "kernel/Kconfig.locks"