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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
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54 drivers that have been replaced by something else, and/or are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
72config LOCK_KERNEL
73 bool
Arnd Bergmann6de5bd12010-09-11 18:00:57 +020074 depends on (SMP || PREEMPT) && BKL
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 default y
76
77config INIT_ENV_ARG_LIMIT
78 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070079 default 32 if !UML
80 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080082 Maximum of each of the number of arguments and environment
83 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
Roland McGrath84336462009-12-21 16:24:06 -080086config CROSS_COMPILE
87 string "Cross-compiler tool prefix"
88 help
89 Same as running 'make CROSS_COMPILE=prefix-' but stored for
90 default make runs in this kernel build directory. You don't
91 need to set this unless you want the configured kernel build
92 directory to select the cross-compiler automatically.
93
Linus Torvalds1da177e2005-04-16 15:20:36 -070094config LOCALVERSION
95 string "Local version - append to kernel release"
96 help
97 Append an extra string to the end of your kernel version.
98 This will show up when you type uname, for example.
99 The string you set here will be appended after the contents of
100 any files with a filename matching localversion* in your
101 object and source tree, in that order. Your total string can
102 be a maximum of 64 characters.
103
Ryan Andersonaaebf432005-07-31 04:57:49 -0400104config LOCALVERSION_AUTO
105 bool "Automatically append version information to the version string"
106 default y
107 help
108 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200109 release tree by looking for git tags that belong to the current
110 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111
112 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200113 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400114 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200115 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400116
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200117 (The actual string used here is the first eight characters produced
118 by running the command:
119
120 $ git rev-parse --verify HEAD
121
122 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400123
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800124config HAVE_KERNEL_GZIP
125 bool
126
127config HAVE_KERNEL_BZIP2
128 bool
129
130config HAVE_KERNEL_LZMA
131 bool
132
Lasse Collin3ebe1242011-01-12 17:01:23 -0800133config HAVE_KERNEL_XZ
134 bool
135
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800136config HAVE_KERNEL_LZO
137 bool
138
Alain Knaff30d65db2009-01-04 22:46:17 +0100139choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800140 prompt "Kernel compression mode"
141 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800142 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 -0800143 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100144 The linux kernel is a kind of self-extracting executable.
145 Several compression algorithms are available, which differ
146 in efficiency, compression and decompression speed.
147 Compression speed is only relevant when building a kernel.
148 Decompression speed is relevant at each boot.
149
150 If you have any problems with bzip2 or lzma compressed
151 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
152 version of this functionality (bzip2 only), for 2.4, was
153 supplied by Christian Ludwig)
154
155 High compression options are mostly useful for users, who
156 are low on disk space (embedded systems), but for whom ram
157 size matters less.
158
159 If in doubt, select 'gzip'
160
161config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800162 bool "Gzip"
163 depends on HAVE_KERNEL_GZIP
164 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800165 The old and tried gzip compression. It provides a good balance
166 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100167
168config KERNEL_BZIP2
169 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800170 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100171 help
172 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800173 Decompression speed is slowest among the three. The kernel
174 size is about 10% smaller with bzip2, in comparison to gzip.
175 Bzip2 uses a large amount of memory. For modern kernels you
176 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100177
178config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800179 bool "LZMA"
180 depends on HAVE_KERNEL_LZMA
181 help
182 The most recent compression algorithm.
183 Its ratio is best, decompression speed is between the other
184 two. Compression is slowest. The kernel size is about 33%
185 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100186
Lasse Collin3ebe1242011-01-12 17:01:23 -0800187config KERNEL_XZ
188 bool "XZ"
189 depends on HAVE_KERNEL_XZ
190 help
191 XZ uses the LZMA2 algorithm and instruction set specific
192 BCJ filters which can improve compression ratio of executable
193 code. The size of the kernel is about 30% smaller with XZ in
194 comparison to gzip. On architectures for which there is a BCJ
195 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
196 will create a few percent smaller kernel than plain LZMA.
197
198 The speed is about the same as with LZMA: The decompression
199 speed of XZ is better than that of bzip2 but worse than gzip
200 and LZO. Compression is slow.
201
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800202config KERNEL_LZO
203 bool "LZO"
204 depends on HAVE_KERNEL_LZO
205 help
206 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200207 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800208 (both compression and decompression) is the fastest.
209
Alain Knaff30d65db2009-01-04 22:46:17 +0100210endchoice
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212config SWAP
213 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200214 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 default y
216 help
217 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100218 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 used to provide more virtual memory than the actual RAM present
220 in your computer. If unsure say Y.
221
222config SYSVIPC
223 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 ---help---
225 Inter Process Communication is a suite of library functions and
226 system calls which let processes (running programs) synchronize and
227 exchange information. It is generally considered to be a good thing,
228 and some programs won't run unless you say Y here. In particular, if
229 you want to run the DOS emulator dosemu under Linux (read the
230 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
231 you'll need to say Y here.
232
233 You can find documentation about IPC with "info ipc" and also in
234 section 6.4 of the Linux Programmer's Guide, available from
235 <http://www.tldp.org/guides.html>.
236
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800237config SYSVIPC_SYSCTL
238 bool
239 depends on SYSVIPC
240 depends on SYSCTL
241 default y
242
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243config POSIX_MQUEUE
244 bool "POSIX Message Queues"
245 depends on NET && EXPERIMENTAL
246 ---help---
247 POSIX variant of message queues is a part of IPC. In POSIX message
248 queues every message has a priority which decides about succession
249 of receiving it by a process. If you want to compile and run
250 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200251 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 POSIX message queues are visible as a filesystem called 'mqueue'
254 and can be mounted somewhere if you want to do filesystem
255 operations on message queues.
256
257 If unsure, say Y.
258
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700259config POSIX_MQUEUE_SYSCTL
260 bool
261 depends on POSIX_MQUEUE
262 depends on SYSCTL
263 default y
264
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265config BSD_PROCESS_ACCT
266 bool "BSD Process Accounting"
267 help
268 If you say Y here, a user level program will be able to instruct the
269 kernel (via a special system call) to write process accounting
270 information to a file: whenever a process exits, information about
271 that process will be appended to the file by the kernel. The
272 information includes things such as creation time, owning user,
273 command name, memory usage, controlling terminal etc. (the complete
274 list is in the struct acct in <file:include/linux/acct.h>). It is
275 up to the user level program to do useful things with this
276 information. This is generally a good idea, so say Y.
277
278config BSD_PROCESS_ACCT_V3
279 bool "BSD Process Accounting version 3 file format"
280 depends on BSD_PROCESS_ACCT
281 default n
282 help
283 If you say Y here, the process accounting information is written
284 in a new file format that also logs the process IDs of each
285 process and it's parent. Note that this file format is incompatible
286 with previous v0/v1/v2 file formats, so you will need updated tools
287 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300288 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530290config FHANDLE
291 bool "open by fhandle syscalls"
292 select EXPORTFS
293 help
294 If you say Y here, a user level program will be able to map
295 file names to handle and then later use the handle for
296 different file system operations. This is useful in implementing
297 userspace file servers, which now track files using handles instead
298 of names. The handle would remain the same even if file names
299 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
300 syscalls.
301
Shailabh Nagarc7572492006-07-14 00:24:40 -0700302config TASKSTATS
303 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
304 depends on NET
305 default n
306 help
307 Export selected statistics for tasks/processes through the
308 generic netlink interface. Unlike BSD process accounting, the
309 statistics are available during the lifetime of tasks/processes as
310 responses to commands. Like BSD accounting, they are sent to user
311 space on task exit.
312
313 Say N if unsure.
314
Shailabh Nagarca74e922006-07-14 00:24:36 -0700315config TASK_DELAY_ACCT
316 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700317 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700318 help
319 Collect information on time spent by a task waiting for system
320 resources like cpu, synchronous block I/O completion and swapping
321 in pages. Such statistics can help in setting a task's priorities
322 relative to other tasks for cpu, io, rss limits etc.
323
324 Say N if unsure.
325
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800326config TASK_XACCT
327 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
328 depends on TASKSTATS
329 help
330 Collect extended task accounting data and send the data
331 to userland for processing over the taskstats interface.
332
333 Say N if unsure.
334
335config TASK_IO_ACCOUNTING
336 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
337 depends on TASK_XACCT
338 help
339 Collect information on the number of bytes of storage I/O which this
340 task has caused.
341
342 Say N if unsure.
343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344config AUDIT
345 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100346 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 help
348 Enable auditing infrastructure that can be used with another
349 kernel subsystem, such as SELinux (which requires this for
350 logging of avc messages output). Does not do system-call
351 auditing without CONFIG_AUDITSYSCALL.
352
353config AUDITSYSCALL
354 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000355 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 default y if SECURITY_SELINUX
357 help
358 Enable low-overhead system-call auditing infrastructure that
359 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500360 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
Eric Paris939a67f2009-12-17 20:12:06 -0500362config AUDIT_WATCH
363 def_bool y
364 depends on AUDITSYSCALL
365 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
Al Viro74c3cbe2007-07-22 08:04:18 -0400367config AUDIT_TREE
368 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400369 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500370 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400371
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000372source "kernel/irq/Kconfig"
373
Mike Travisc903ff82009-01-15 12:28:29 -0800374menu "RCU Subsystem"
375
376choice
377 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700378 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800379
Mike Travisc903ff82009-01-15 12:28:29 -0800380config TREE_RCU
381 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700382 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800383 help
384 This option selects the RCU implementation that is
385 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700386 thousands of CPUs. It also scales down nicely to
387 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800388
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700389config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700390 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700391 depends on PREEMPT
392 help
393 This option selects the RCU implementation that is
394 designed for very large SMP systems with hundreds or
395 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700396 is also required. It also scales down nicely to
397 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700398
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700399config TINY_RCU
400 bool "UP-only small-memory-footprint RCU"
401 depends on !SMP
402 help
403 This option selects the RCU implementation that is
404 designed for UP systems from which real-time response
405 is not required. This option greatly reduces the
406 memory footprint of RCU.
407
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700408config TINY_PREEMPT_RCU
409 bool "Preemptible UP-only small-memory-footprint RCU"
410 depends on !SMP && PREEMPT
411 help
412 This option selects the RCU implementation that is designed
413 for real-time UP systems. This option greatly reduces the
414 memory footprint of RCU.
415
Mike Travisc903ff82009-01-15 12:28:29 -0800416endchoice
417
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700418config PREEMPT_RCU
419 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
420 help
421 This option enables preemptible-RCU code that is common between
422 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
423
Mike Travisc903ff82009-01-15 12:28:29 -0800424config RCU_TRACE
425 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800426 help
427 This option provides tracing in RCU which presents stats
428 in debugfs for debugging RCU implementation.
429
430 Say Y here if you want to enable RCU tracing
431 Say N if you are unsure.
432
433config RCU_FANOUT
434 int "Tree-based hierarchical RCU fanout value"
435 range 2 64 if 64BIT
436 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700437 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800438 default 64 if 64BIT
439 default 32 if !64BIT
440 help
441 This option controls the fanout of hierarchical implementations
442 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700443 large numbers of CPUs. This value must be at least the fourth
444 root of NR_CPUS, which allows NR_CPUS to be insanely large.
445 The default value of RCU_FANOUT should be used for production
446 systems, but if you are stress-testing the RCU implementation
447 itself, small RCU_FANOUT values allow you to test large-system
448 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800449
450 Select a specific number if testing RCU itself.
451 Take the default if unsure.
452
453config RCU_FANOUT_EXACT
454 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700455 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800456 default n
457 help
458 This option forces use of the exact RCU_FANOUT value specified,
459 regardless of imbalances in the hierarchy. This is useful for
460 testing RCU itself, and might one day be useful on systems with
461 strong NUMA behavior.
462
463 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
464
465 Say N if unsure.
466
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800467config RCU_FAST_NO_HZ
468 bool "Accelerate last non-dyntick-idle CPU's grace periods"
469 depends on TREE_RCU && NO_HZ && SMP
470 default n
471 help
472 This option causes RCU to attempt to accelerate grace periods
473 in order to allow the final CPU to enter dynticks-idle state
474 more quickly. On the other hand, this option increases the
475 overhead of the dynticks-idle checking, particularly on systems
476 with large numbers of CPUs.
477
478 Say Y if energy efficiency is critically important, particularly
479 if you have relatively few CPUs.
480
481 Say N if you are unsure.
482
Mike Travisc903ff82009-01-15 12:28:29 -0800483config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700484 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800485 select DEBUG_FS
486 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700487 This option provides tracing for the TREE_RCU and
488 TREE_PREEMPT_RCU implementations, permitting Makefile to
489 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800490
Paul E. McKenney24278d12010-09-27 17:25:23 -0700491config RCU_BOOST
492 bool "Enable RCU priority boosting"
493 depends on RT_MUTEXES && TINY_PREEMPT_RCU
494 default n
495 help
496 This option boosts the priority of preempted RCU readers that
497 block the current preemptible RCU grace period for too long.
498 This option also prevents heavy loads from blocking RCU
499 callback invocation for all flavors of RCU.
500
501 Say Y here if you are working with real-time apps or heavy loads
502 Say N here if you are unsure.
503
504config RCU_BOOST_PRIO
505 int "Real-time priority to boost RCU readers to"
506 range 1 99
507 depends on RCU_BOOST
508 default 1
509 help
510 This option specifies the real-time priority to which preempted
511 RCU readers are to be boosted. If you are working with CPU-bound
512 real-time applications, you should specify a priority higher then
513 the highest-priority CPU-bound application.
514
515 Specify the real-time priority, or take the default if unsure.
516
517config RCU_BOOST_DELAY
518 int "Milliseconds to delay boosting after RCU grace-period start"
519 range 0 3000
520 depends on RCU_BOOST
521 default 500
522 help
523 This option specifies the time to wait after the beginning of
524 a given grace period before priority-boosting preempted RCU
525 readers blocking that grace period. Note that any RCU reader
526 blocking an expedited RCU grace period is boosted immediately.
527
528 Accept the default if unsure.
529
Mike Travisc903ff82009-01-15 12:28:29 -0800530endmenu # "RCU Subsystem"
531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700533 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 ---help---
535 This option enables the complete Linux kernel ".config" file
536 contents to be saved in the kernel. It provides documentation
537 of which kernel options are used in a running kernel or in an
538 on-disk kernel. This information can be extracted from the kernel
539 image file with the script scripts/extract-ikconfig and used as
540 input to rebuild the current kernel or to build another kernel.
541 It can also be extracted from a running kernel by reading
542 /proc/config.gz if enabled (below).
543
544config IKCONFIG_PROC
545 bool "Enable access to .config through /proc/config.gz"
546 depends on IKCONFIG && PROC_FS
547 ---help---
548 This option enables access to the kernel configuration file
549 through /proc/config.gz.
550
Alistair John Strachan794543a2007-05-08 00:31:15 -0700551config LOG_BUF_SHIFT
552 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
553 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700554 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700555 help
556 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700557 Examples:
558 17 => 128 KB
559 16 => 64 KB
560 15 => 32 KB
561 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700562 13 => 8 KB
563 12 => 4 KB
564
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800565#
566# Architectures with an unreliable sched_clock() should select this:
567#
568config HAVE_UNSTABLE_SCHED_CLOCK
569 bool
570
Li Zefan23964d22009-01-15 13:50:58 -0800571menuconfig CGROUPS
572 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800573 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700574 help
Li Zefan23964d22009-01-15 13:50:58 -0800575 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800576 use with process control subsystems such as Cpusets, CFS, memory
577 controls or device isolation.
578 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800579 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800580 - Documentation/cgroups/ (features for grouping, isolation
581 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700582
583 Say N if unsure.
584
Li Zefan23964d22009-01-15 13:50:58 -0800585if CGROUPS
586
Paul Menage006cb992007-10-18 23:39:43 -0700587config CGROUP_DEBUG
588 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700589 default n
Paul Menage006cb992007-10-18 23:39:43 -0700590 help
591 This option enables a simple cgroup subsystem that
592 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800593 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700594
Li Zefan23964d22009-01-15 13:50:58 -0800595 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700596
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700597config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800598 bool "Namespace cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800599 help
600 Provides a simple namespace cgroup subsystem to
601 provide hierarchical naming of sets of namespaces,
602 for instance virtual servers and checkpoint/restart
603 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700604
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700605config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800606 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800607 help
608 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700609 cgroup.
610
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700611config CGROUP_DEVICE
612 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700613 help
614 Provides a cgroup implementing whitelists for devices which
615 a process in the cgroup can mknod or open.
616
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617config CPUSETS
618 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700620 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 allow dynamically partitioning a system into sets of CPUs and
622 Memory Nodes and assigning tasks to run only within those sets.
623 This is primarily useful on large SMP or NUMA systems.
624
625 Say N if unsure.
626
Li Zefan23964d22009-01-15 13:50:58 -0800627config PROC_PID_CPUSET
628 bool "Include legacy /proc/<pid>/cpuset file"
629 depends on CPUSETS
630 default y
631
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100632config CGROUP_CPUACCT
633 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100634 help
635 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800636 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100637
Pavel Emelianove552b662008-02-07 00:13:49 -0800638config RESOURCE_COUNTERS
639 bool "Resource counters"
640 help
641 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800642 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800643
Balbir Singh00f0b822008-03-04 14:28:39 -0800644config CGROUP_MEM_RES_CTLR
645 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700646 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700647 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800648 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700649 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100650 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800651
652 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700653 associated with each page of memory in the system. By this,
654 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
655 usage tracking struct at boot. Total amount of this is printed out
656 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800657
658 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700659 sure you need the memory resource controller. Even when you enable
660 this, you can set "cgroup_disable=memory" at your boot option to
661 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800662 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800663
Balbir Singhcf475ad2008-04-29 01:00:16 -0700664 This config option also selects MM_OWNER config option, which
665 could in turn add some fork/exit overhead.
666
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800667config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700668 bool "Memory Resource Controller Swap Extension"
669 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800670 help
671 Add swap management feature to memory resource controller. When you
672 enable this, you can limit mem+swap usage per cgroup. In other words,
673 when you disable this, memory resource controller has no cares to
674 usage of swap...a process can exhaust all of the swap. This extension
675 is useful when you want to avoid exhaustion swap but this itself
676 adds more overheads and consumes memory for remembering information.
677 Especially if you use 32bit system or small memory system, please
678 be careful about enabling this. When memory resource controller
679 is disabled by boot option, this will be automatically disabled and
680 there will be no overhead from this. Even when you set this config=y,
681 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700682 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
683 size is 4096bytes, 512k per 1Gbytes of swap.
Michal Hockoa42c3902010-11-24 12:57:08 -0800684config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
685 bool "Memory Resource Controller Swap Extension enabled by default"
686 depends on CGROUP_MEM_RES_CTLR_SWAP
687 default y
688 help
689 Memory Resource Controller Swap Extension comes with its price in
690 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700691 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800692 and let the user enable it by swapaccount boot command line
693 parameter should have this option unselected.
694 For those who want to have the feature enabled by default should
695 select this option (if, for some reason, they need to disable it
696 then noswapaccount does the trick).
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800697
Dhaval Giani7c941432010-01-20 13:26:18 +0100698menuconfig CGROUP_SCHED
699 bool "Group CPU scheduler"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700700 depends on EXPERIMENTAL
Dhaval Giani7c941432010-01-20 13:26:18 +0100701 default n
702 help
703 This feature lets CPU scheduler recognize task groups and control CPU
704 bandwidth allocation to such task groups. It uses cgroups to group
705 tasks.
706
707if CGROUP_SCHED
708config FAIR_GROUP_SCHED
709 bool "Group scheduling for SCHED_OTHER"
710 depends on CGROUP_SCHED
711 default CGROUP_SCHED
712
713config RT_GROUP_SCHED
714 bool "Group scheduling for SCHED_RR/FIFO"
715 depends on EXPERIMENTAL
716 depends on CGROUP_SCHED
717 default n
718 help
719 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800720 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100721 schedule realtime tasks for non-root users until you allocate
722 realtime bandwidth for them.
723 See Documentation/scheduler/sched-rt-group.txt for more information.
724
725endif #CGROUP_SCHED
726
Vivek Goyalafc24d42010-04-26 19:27:56 +0200727config BLK_CGROUP
728 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700729 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200730 default n
731 ---help---
732 Generic block IO controller cgroup interface. This is the common
733 cgroup interface which should be used by various IO controlling
734 policies.
735
736 Currently, CFQ IO scheduler uses it to recognize task groups and
737 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400738 to such task groups. It is also used by bio throttling logic in
739 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200740
741 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400742 One needs to also enable actual IO controlling logic/policy. For
743 enabling proportional weight division of disk bandwidth in CFQ seti
744 CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
745 CONFIG_BLK_THROTTLE=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200746
747 See Documentation/cgroups/blkio-controller.txt for more information.
748
749config DEBUG_BLK_CGROUP
750 bool "Enable Block IO controller debugging"
751 depends on BLK_CGROUP
752 default n
753 ---help---
754 Enable some debugging help. Currently it exports additional stat
755 files in a cgroup which can be useful for debugging.
756
Li Zefan23964d22009-01-15 13:50:58 -0800757endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800758
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700759menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800760 bool "Namespaces support" if EXPERT
761 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800762 help
763 Provides the way to make tasks work with different objects using
764 the same id. For example same IPC id may refer to different objects
765 or same user id or pid may refer to different tasks when used in
766 different namespaces.
767
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700768if NAMESPACES
769
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800770config UTS_NS
771 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700772 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800773 help
774 In this namespace tasks see different info provided with the
775 uname() system call
776
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800777config IPC_NS
778 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700779 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700780 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800781 help
782 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700783 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800784
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800785config USER_NS
786 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700787 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700788 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800789 help
790 This allows containers, i.e. vservers, to use user namespaces
791 to provide different user info for different servers.
792 If unsure, say N.
793
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800794config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700795 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700796 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800797 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300798 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100799 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800800 pid namespaces. This is a building block of containers.
801
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800802config NET_NS
803 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700804 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700805 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800806 help
807 Allow user space to create what appear to be multiple instances
808 of the network stack.
809
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700810endif # NAMESPACES
811
Mike Galbraith5091faa2010-11-30 14:18:03 +0100812config SCHED_AUTOGROUP
813 bool "Automatic process group scheduling"
814 select EVENTFD
815 select CGROUPS
816 select CGROUP_SCHED
817 select FAIR_GROUP_SCHED
818 help
819 This option optimizes the scheduler for common desktop workloads by
820 automatically creating and populating task groups. This separation
821 of workloads isolates aggressive CPU burners (like build jobs) from
822 desktop applications. Task group autogeneration is currently based
823 upon task session.
824
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700825config MM_OWNER
826 bool
827
828config SYSFS_DEPRECATED
829 bool "enable deprecated sysfs features to support old userspace tools"
830 depends on SYSFS
831 default n
832 help
833 This option adds code that switches the layout of the "block" class
834 devices, to not show up in /sys/class/block/, but only in
835 /sys/block/.
836
837 This switch is only active when the sysfs.deprecated=1 boot option is
838 passed or the SYSFS_DEPRECATED_V2 option is set.
839
840 This option allows new kernels to run on old distributions and tools,
841 which might get confused by /sys/class/block/. Since 2007/2008 all
842 major distributions and tools handle this just fine.
843
844 Recent distributions and userspace tools after 2009/2010 depend on
845 the existence of /sys/class/block/, and will not work with this
846 option enabled.
847
848 Only if you are using a new kernel on an old distribution, you might
849 need to say Y here.
850
851config SYSFS_DEPRECATED_V2
852 bool "enabled deprecated sysfs features by default"
853 default n
854 depends on SYSFS
855 depends on SYSFS_DEPRECATED
856 help
857 Enable deprecated sysfs by default.
858
859 See the CONFIG_SYSFS_DEPRECATED option for more details about this
860 option.
861
862 Only if you are using a new kernel on an old distribution, you might
863 need to say Y here. Even then, odds are you would not need it
864 enabled, you can always pass the boot option if absolutely necessary.
865
866config RELAY
867 bool "Kernel->user space relay support (formerly relayfs)"
868 help
869 This option enables support for relay interface support in
870 certain file systems (such as debugfs).
871 It is designed to provide an efficient mechanism for tools and
872 facilities to relay large amounts of data from kernel space to
873 user space.
874
875 If unsure, say N.
876
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800877config BLK_DEV_INITRD
878 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
879 depends on BROKEN || !FRV
880 help
881 The initial RAM filesystem is a ramfs which is loaded by the
882 boot loader (loadlin or lilo) and that is mounted as root
883 before the normal boot procedure. It is typically used to
884 load modules needed to mount the "real" root file system,
885 etc. See <file:Documentation/initrd.txt> for details.
886
887 If RAM disk support (BLK_DEV_RAM) is also included, this
888 also enables initial RAM disk (initrd) support and adds
889 15 Kbytes (more on some other architectures) to the kernel size.
890
891 If unsure say Y.
892
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800893if BLK_DEV_INITRD
894
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200895source "usr/Kconfig"
896
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800897endif
898
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800899config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200900 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800901 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800902 help
903 Enabling this option will pass "-Os" instead of "-O2" to gcc
904 resulting in a smaller kernel.
905
jkacur775a7222008-07-16 00:31:16 +0200906 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800907
Randy Dunlap08470622006-09-30 23:28:13 -0700908config SYSCTL
909 bool
910
Randy Dunlapb943c462009-03-10 12:55:46 -0700911config ANON_INODES
912 bool
913
David Rientjes6a108a12011-01-20 14:44:16 -0800914menuconfig EXPERT
915 bool "Configure standard kernel features (expert users)"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 help
917 This option allows certain base kernel options and settings
918 to be disabled or tweaked. This is for specialized
919 environments which can tolerate a "non-standard" kernel.
920 Only use this if you really know what you are doing.
921
David Rientjes6a108a12011-01-20 14:44:16 -0800922config EMBEDDED
923 bool "Embedded system"
924 select EXPERT
925 help
926 This option should be enabled if compiling the kernel for
927 an embedded system so certain expert options are available
928 for configuration.
929
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700930config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800931 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700932 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 -0700933 default y
934 help
935 This enables the legacy 16-bit UID syscall wrappers.
936
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700937config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800938 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800939 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800940 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700941 select SYSCTL
942 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800943 sys_sysctl uses binary paths that have been found challenging
944 to properly maintain and use. The interface in /proc/sys
945 using paths with ascii names is now the primary path to this
946 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700947
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800948 Almost nothing using the binary sysctl interface so if you are
949 trying to save some space it is probably safe to disable this,
950 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700951
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800952 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700953
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800955 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 default y
957 help
958 Say Y here to let the kernel print out symbolic crash information and
959 symbolic stack backtraces. This increases the size of the kernel
960 somewhat, as all symbols have to be loaded into the kernel image.
961
962config KALLSYMS_ALL
963 bool "Include all symbols in kallsyms"
964 depends on DEBUG_KERNEL && KALLSYMS
965 help
966 Normally kallsyms only contains the symbols of functions, for nicer
967 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200968 symbols too: say Y here to include all symbols, if you need them
969 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970
971 Say N.
972
973config KALLSYMS_EXTRA_PASS
974 bool "Do an extra kallsyms pass"
975 depends on KALLSYMS
976 help
977 If kallsyms is not working correctly, the build will fail with
978 inconsistent kallsyms data. If that occurs, log a bug report and
979 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
980 Always say N here unless you find a bug in kallsyms, which must be
981 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
982 you wait for kallsyms to be fixed.
983
Matt Mackalld59745c2005-05-01 08:59:02 -0700984
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800985config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -0800986 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800987 default y
988 help
989 This option is provided for the case where no hotplug or uevent
990 capabilities is wanted by the kernel. You should only consider
991 disabling this option for embedded systems that do not use modules, a
992 dynamic /dev tree, or dynamic device discovery. Just say Y.
993
Matt Mackalld59745c2005-05-01 08:59:02 -0700994config PRINTK
995 default y
David Rientjes6a108a12011-01-20 14:44:16 -0800996 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -0700997 help
998 This option enables normal printk support. Removing it
999 eliminates most of the message strings from the kernel image
1000 and makes the kernel more or less silent. As this makes it
1001 very difficult to diagnose system problems, saying N here is
1002 strongly discouraged.
1003
Matt Mackallc8538a72005-05-01 08:59:01 -07001004config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001005 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001006 default y
1007 help
1008 Disabling this option eliminates support for BUG and WARN, reducing
1009 the size of your kernel image and potentially quietly ignoring
1010 numerous fatal conditions. You should only consider disabling this
1011 option for embedded systems with no facilities for reporting errors.
1012 Just say Y.
1013
Matt Mackall708e9a72006-01-08 01:05:25 -08001014config ELF_CORE
1015 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001016 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001017 help
1018 Enable support for generating core dumps. Disabling saves about 4k.
1019
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001020config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001021 bool "Enable PC-Speaker support" if EXPERT
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001022 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
1023 default y
1024 help
1025 This option allows to disable the internal PC-Speaker
1026 support, saving some memory.
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028config BASE_FULL
1029 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001030 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 help
1032 Disabling this option reduces the size of miscellaneous core
1033 kernel data structures. This saves memory on small machines,
1034 but may reduce performance.
1035
1036config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001037 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001039 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 help
1041 Disabling this option will cause the kernel to be built without
1042 support for "fast userspace mutexes". The resulting kernel may not
1043 run glibc-based applications correctly.
1044
1045config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001046 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001048 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 help
1050 Disabling this option will cause the kernel to be built without
1051 support for epoll family of system calls.
1052
Davide Libenzifba2afa2007-05-10 22:23:13 -07001053config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001054 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001055 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001056 default y
1057 help
1058 Enable the signalfd() system call that allows to receive signals
1059 on a file descriptor.
1060
1061 If unsure, say Y.
1062
Davide Libenzib215e282007-05-10 22:23:16 -07001063config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001064 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001065 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001066 default y
1067 help
1068 Enable the timerfd() system call that allows to receive timer
1069 events on a file descriptor.
1070
1071 If unsure, say Y.
1072
Davide Libenzie1ad7462007-05-10 22:23:19 -07001073config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001074 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001075 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001076 default y
1077 help
1078 Enable the eventfd() system call that allows to receive both
1079 kernel notification (ie. KAIO) or userspace notifications.
1080
1081 If unsure, say Y.
1082
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001084 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 default y
1086 depends on MMU
1087 help
1088 The shmem is an internal filesystem used to manage shared memory.
1089 It is backed by swap and manages resource limits. It is also exported
1090 to userspace as tmpfs if TMPFS is enabled. Disabling this
1091 option replaces shmem and tmpfs with the much simpler ramfs code,
1092 which may be appropriate on small systems without swap.
1093
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001094config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001095 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001096 default y
1097 help
1098 This option enables POSIX asynchronous I/O which may by used
1099 by some high performance threaded applications. Disabling
1100 this option saves about 7k.
1101
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001102config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001103 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001104 help
1105 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001106
Peter Zijlstra906010b2009-09-21 16:08:49 +02001107config PERF_USE_VMALLOC
1108 bool
1109 help
1110 See tools/perf/design.txt for details
1111
Ingo Molnar57c0c152009-09-21 12:20:38 +02001112menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001113
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001114config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001115 bool "Kernel performance events and counters"
1116 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001117 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001118 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001119 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001120 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001121 Enable kernel support for various performance events provided
1122 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001123
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001124 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001125 use of generic tracepoints.
1126
1127 Most modern CPUs support performance events via performance
1128 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001129 types of hw events: such as instructions executed, cachemisses
1130 suffered, or branches mis-predicted - without slowing down the
1131 kernel or applications. These registers can also trigger interrupts
1132 when a threshold number of events have passed - and can thus be
1133 used to profile the code that runs on that CPU.
1134
Ingo Molnar57c0c152009-09-21 12:20:38 +02001135 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001136 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001137 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001138 provides per task and per CPU counters, and it provides event
1139 capabilities on top of those.
1140
1141 Say Y if unsure.
1142
Ingo Molnar57c0c152009-09-21 12:20:38 +02001143config PERF_COUNTERS
1144 bool "Kernel performance counters (old config option)"
1145 depends on HAVE_PERF_EVENTS
1146 help
1147 This config has been obsoleted by the PERF_EVENTS
1148 config option - please see that one for details.
1149
1150 It has no effect on the kernel whether you enable
1151 it or not, it is a compatibility placeholder.
1152
1153 Say N if unsure.
1154
Peter Zijlstra906010b2009-09-21 16:08:49 +02001155config DEBUG_PERF_USE_VMALLOC
1156 default n
1157 bool "Debug: use vmalloc to back perf mmap() buffers"
1158 depends on PERF_EVENTS && DEBUG_KERNEL
1159 select PERF_USE_VMALLOC
1160 help
1161 Use vmalloc memory to back perf mmap() buffers.
1162
1163 Mostly useful for debugging the vmalloc code on platforms
1164 that don't require it.
1165
1166 Say N if unsure.
1167
Thomas Gleixner0793a612008-12-04 20:12:29 +01001168endmenu
1169
Christoph Lameterf8891e52006-06-30 01:55:45 -07001170config VM_EVENT_COUNTERS
1171 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001172 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001173 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001174 VM event counters are needed for event counts to be shown.
1175 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001176 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001177 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001178
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001179config PCI_QUIRKS
1180 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001181 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001182 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001183 help
1184 This enables workarounds for various PCI chipset
1185 bugs/quirks. Disable this only if your target machine is
1186 unaffected by PCI quirks.
1187
Christoph Lameter41ecc552007-05-09 02:32:44 -07001188config SLUB_DEBUG
1189 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001190 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001191 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001192 help
1193 SLUB has extensive debug support features. Disabling these can
1194 result in significant savings in code size. This also disables
1195 SLUB sysfs support. /sys/slab will not exist and there will be
1196 no support for cache validation etc.
1197
Randy Dunlapb943c462009-03-10 12:55:46 -07001198config COMPAT_BRK
1199 bool "Disable heap randomization"
1200 default y
1201 help
1202 Randomizing heap placement makes heap exploits harder, but it
1203 also breaks ancient binaries (including anything libc5 based).
1204 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001205 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001206 /proc/sys/kernel/randomize_va_space to 2.
1207
1208 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1209
Christoph Lameter81819f02007-05-06 14:49:36 -07001210choice
1211 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001212 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001213 help
1214 This option allows to select a slab allocator.
1215
1216config SLAB
1217 bool "SLAB"
1218 help
1219 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001220 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001221 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001222
1223config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001224 bool "SLUB (Unqueued Allocator)"
1225 help
1226 SLUB is a slab allocator that minimizes cache line usage
1227 instead of managing queues of cached objects (SLAB approach).
1228 Per cpu caching is realized using slabs of objects instead
1229 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001230 and has enhanced diagnostics. SLUB is the default choice for
1231 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001232
1233config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001234 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001235 bool "SLOB (Simple Allocator)"
1236 help
Matt Mackall37291452008-02-04 22:29:38 -08001237 SLOB replaces the stock allocator with a drastically simpler
1238 allocator. SLOB is generally more space efficient but
1239 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001240
1241endchoice
1242
Jie Zhangea637632009-12-14 18:00:02 -08001243config MMAP_ALLOW_UNINITIALIZED
1244 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001245 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001246 default n
1247 help
1248 Normally, and according to the Linux spec, anonymous memory obtained
1249 from mmap() has it's contents cleared before it is passed to
1250 userspace. Enabling this config option allows you to request that
1251 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1252 providing a huge performance boost. If this option is not enabled,
1253 then the flag will be ignored.
1254
1255 This is taken advantage of by uClibc's malloc(), and also by
1256 ELF-FDPIC binfmt's brk and stack allocator.
1257
1258 Because of the obvious security issues, this option should only be
1259 enabled on embedded devices where you control what is run in
1260 userspace. Since that isn't generally a problem on no-MMU systems,
1261 it is normally safe to say Y here.
1262
1263 See Documentation/nommu-mmap.txt for more information.
1264
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001265config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001266 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001267 help
1268 Say Y here to enable the extended profiling support mechanisms used
1269 by profilers such as OProfile.
1270
Ingo Molnar5f87f112008-07-23 14:15:22 +02001271#
1272# Place an empty function call at each tracepoint site. Can be
1273# dynamically changed for a probe function.
1274#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001275config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001276 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001277
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001278source "arch/Kconfig"
1279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280endmenu # General setup
1281
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001282config HAVE_GENERIC_DMA_COHERENT
1283 bool
1284 default n
1285
Linus Torvalds158a9622008-01-02 13:04:48 -08001286config SLABINFO
1287 bool
1288 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001289 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001290 default y
1291
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001292config RT_MUTEXES
1293 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001294
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295config BASE_SMALL
1296 int
1297 default 0 if BASE_FULL
1298 default 1 if !BASE_FULL
1299
Jan Engelhardt66da5732007-07-15 23:39:29 -07001300menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 bool "Enable loadable module support"
1302 help
1303 Kernel modules are small pieces of compiled code which can
1304 be inserted in the running kernel, rather than being
1305 permanently built into the kernel. You use the "modprobe"
1306 tool to add (and sometimes remove) them. If you say Y here,
1307 many parts of the kernel can be built as modules (by
1308 answering M instead of Y where indicated): this is most
1309 useful for infrequently used options which are not required
1310 for booting. For more information, see the man pages for
1311 modprobe, lsmod, modinfo, insmod and rmmod.
1312
1313 If you say Y here, you will need to run "make
1314 modules_install" to put the modules under /lib/modules/
1315 where modprobe can find them (you may need to be root to do
1316 this).
1317
1318 If unsure, say Y.
1319
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001320if MODULES
1321
Linus Torvalds826e4502008-05-04 17:04:16 -07001322config MODULE_FORCE_LOAD
1323 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001324 default n
1325 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001326 Allow loading of modules without version information (ie. modprobe
1327 --force). Forced module loading sets the 'F' (forced) taint flag and
1328 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001329
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330config MODULE_UNLOAD
1331 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 help
1333 Without this option you will not be able to unload any
1334 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001335 anyway), which makes your kernel smaller, faster
1336 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337
1338config MODULE_FORCE_UNLOAD
1339 bool "Forced module unloading"
1340 depends on MODULE_UNLOAD && EXPERIMENTAL
1341 help
1342 This option allows you to force a module to unload, even if the
1343 kernel believes it is unsafe: the kernel will remove the module
1344 without waiting for anyone to stop using it (using the -f option to
1345 rmmod). This is mainly for kernel developers and desperate users.
1346 If unsure, say N.
1347
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001349 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 help
1351 Usually, you have to use modules compiled with your kernel.
1352 Saying Y here makes it sometimes possible to use modules
1353 compiled for different kernels, by adding enough information
1354 to the modules to (hopefully) spot any changes which would
1355 make them incompatible with the kernel you are running. If
1356 unsure, say N.
1357
1358config MODULE_SRCVERSION_ALL
1359 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 help
1361 Modules which contain a MODULE_VERSION get an extra "srcversion"
1362 field inserted into their modinfo section, which contains a
1363 sum of the source files which made it. This helps maintainers
1364 see exactly which source was used to build a module (since
1365 others sometimes change the module source without updating
1366 the version). With this option, such a "srcversion" field
1367 will be created for all modules. If unsure, say N.
1368
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001369endif # MODULES
1370
Rusty Russell98a79d62008-12-13 21:19:41 +10301371config INIT_ALL_POSSIBLE
1372 bool
1373 help
1374 Back when each arch used to define their own cpu_online_map and
1375 cpu_possible_map, some of them chose to initialize cpu_possible_map
1376 with all 1s, and others with all 0s. When they were centralised,
1377 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001378 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301379
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380config STOP_MACHINE
1381 bool
1382 default y
1383 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1384 help
1385 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001386
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001387source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001388
1389config PREEMPT_NOTIFIERS
1390 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001391
Steffen Klassert16295be2010-01-06 19:47:10 +11001392config PADATA
1393 depends on SMP
1394 bool
1395
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001396source "kernel/Kconfig.locks"