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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54 drivers that have been replaced by something else, and/or are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
Linus Torvalds1da177e2005-04-16 15:20:36 -070072config INIT_ENV_ARG_LIMIT
73 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070074 default 32 if !UML
75 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080077 Maximum of each of the number of arguments and environment
78 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Roland McGrath84336462009-12-21 16:24:06 -080081config CROSS_COMPILE
82 string "Cross-compiler tool prefix"
83 help
84 Same as running 'make CROSS_COMPILE=prefix-' but stored for
85 default make runs in this kernel build directory. You don't
86 need to set this unless you want the configured kernel build
87 directory to select the cross-compiler automatically.
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089config LOCALVERSION
90 string "Local version - append to kernel release"
91 help
92 Append an extra string to the end of your kernel version.
93 This will show up when you type uname, for example.
94 The string you set here will be appended after the contents of
95 any files with a filename matching localversion* in your
96 object and source tree, in that order. Your total string can
97 be a maximum of 64 characters.
98
Ryan Andersonaaebf432005-07-31 04:57:49 -040099config LOCALVERSION_AUTO
100 bool "Automatically append version information to the version string"
101 default y
102 help
103 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200104 release tree by looking for git tags that belong to the current
105 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400106
107 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200108 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400109 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200112 (The actual string used here is the first eight characters produced
113 by running the command:
114
115 $ git rev-parse --verify HEAD
116
117 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400118
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119config HAVE_KERNEL_GZIP
120 bool
121
122config HAVE_KERNEL_BZIP2
123 bool
124
125config HAVE_KERNEL_LZMA
126 bool
127
Lasse Collin3ebe1242011-01-12 17:01:23 -0800128config HAVE_KERNEL_XZ
129 bool
130
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800131config HAVE_KERNEL_LZO
132 bool
133
Alain Knaff30d65db2009-01-04 22:46:17 +0100134choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800135 prompt "Kernel compression mode"
136 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800137 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800138 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100139 The linux kernel is a kind of self-extracting executable.
140 Several compression algorithms are available, which differ
141 in efficiency, compression and decompression speed.
142 Compression speed is only relevant when building a kernel.
143 Decompression speed is relevant at each boot.
144
145 If you have any problems with bzip2 or lzma compressed
146 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
147 version of this functionality (bzip2 only), for 2.4, was
148 supplied by Christian Ludwig)
149
150 High compression options are mostly useful for users, who
151 are low on disk space (embedded systems), but for whom ram
152 size matters less.
153
154 If in doubt, select 'gzip'
155
156config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800157 bool "Gzip"
158 depends on HAVE_KERNEL_GZIP
159 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800160 The old and tried gzip compression. It provides a good balance
161 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100162
163config KERNEL_BZIP2
164 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800165 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100166 help
167 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800168 Decompression speed is slowest among the three. The kernel
169 size is about 10% smaller with bzip2, in comparison to gzip.
170 Bzip2 uses a large amount of memory. For modern kernels you
171 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100172
173config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800174 bool "LZMA"
175 depends on HAVE_KERNEL_LZMA
176 help
177 The most recent compression algorithm.
178 Its ratio is best, decompression speed is between the other
179 two. Compression is slowest. The kernel size is about 33%
180 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100181
Lasse Collin3ebe1242011-01-12 17:01:23 -0800182config KERNEL_XZ
183 bool "XZ"
184 depends on HAVE_KERNEL_XZ
185 help
186 XZ uses the LZMA2 algorithm and instruction set specific
187 BCJ filters which can improve compression ratio of executable
188 code. The size of the kernel is about 30% smaller with XZ in
189 comparison to gzip. On architectures for which there is a BCJ
190 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
191 will create a few percent smaller kernel than plain LZMA.
192
193 The speed is about the same as with LZMA: The decompression
194 speed of XZ is better than that of bzip2 but worse than gzip
195 and LZO. Compression is slow.
196
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800197config KERNEL_LZO
198 bool "LZO"
199 depends on HAVE_KERNEL_LZO
200 help
201 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200202 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800203 (both compression and decompression) is the fastest.
204
Alain Knaff30d65db2009-01-04 22:46:17 +0100205endchoice
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207config SWAP
208 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200209 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 default y
211 help
212 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100213 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 used to provide more virtual memory than the actual RAM present
215 in your computer. If unsure say Y.
216
217config SYSVIPC
218 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 ---help---
220 Inter Process Communication is a suite of library functions and
221 system calls which let processes (running programs) synchronize and
222 exchange information. It is generally considered to be a good thing,
223 and some programs won't run unless you say Y here. In particular, if
224 you want to run the DOS emulator dosemu under Linux (read the
225 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
226 you'll need to say Y here.
227
228 You can find documentation about IPC with "info ipc" and also in
229 section 6.4 of the Linux Programmer's Guide, available from
230 <http://www.tldp.org/guides.html>.
231
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800232config SYSVIPC_SYSCTL
233 bool
234 depends on SYSVIPC
235 depends on SYSCTL
236 default y
237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238config POSIX_MQUEUE
239 bool "POSIX Message Queues"
240 depends on NET && EXPERIMENTAL
241 ---help---
242 POSIX variant of message queues is a part of IPC. In POSIX message
243 queues every message has a priority which decides about succession
244 of receiving it by a process. If you want to compile and run
245 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200246 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 POSIX message queues are visible as a filesystem called 'mqueue'
249 and can be mounted somewhere if you want to do filesystem
250 operations on message queues.
251
252 If unsure, say Y.
253
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700254config POSIX_MQUEUE_SYSCTL
255 bool
256 depends on POSIX_MQUEUE
257 depends on SYSCTL
258 default y
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260config BSD_PROCESS_ACCT
261 bool "BSD Process Accounting"
262 help
263 If you say Y here, a user level program will be able to instruct the
264 kernel (via a special system call) to write process accounting
265 information to a file: whenever a process exits, information about
266 that process will be appended to the file by the kernel. The
267 information includes things such as creation time, owning user,
268 command name, memory usage, controlling terminal etc. (the complete
269 list is in the struct acct in <file:include/linux/acct.h>). It is
270 up to the user level program to do useful things with this
271 information. This is generally a good idea, so say Y.
272
273config BSD_PROCESS_ACCT_V3
274 bool "BSD Process Accounting version 3 file format"
275 depends on BSD_PROCESS_ACCT
276 default n
277 help
278 If you say Y here, the process accounting information is written
279 in a new file format that also logs the process IDs of each
280 process and it's parent. Note that this file format is incompatible
281 with previous v0/v1/v2 file formats, so you will need updated tools
282 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300283 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530285config FHANDLE
286 bool "open by fhandle syscalls"
287 select EXPORTFS
288 help
289 If you say Y here, a user level program will be able to map
290 file names to handle and then later use the handle for
291 different file system operations. This is useful in implementing
292 userspace file servers, which now track files using handles instead
293 of names. The handle would remain the same even if file names
294 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
295 syscalls.
296
Shailabh Nagarc7572492006-07-14 00:24:40 -0700297config TASKSTATS
298 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
299 depends on NET
300 default n
301 help
302 Export selected statistics for tasks/processes through the
303 generic netlink interface. Unlike BSD process accounting, the
304 statistics are available during the lifetime of tasks/processes as
305 responses to commands. Like BSD accounting, they are sent to user
306 space on task exit.
307
308 Say N if unsure.
309
Shailabh Nagarca74e922006-07-14 00:24:36 -0700310config TASK_DELAY_ACCT
311 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700312 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700313 help
314 Collect information on time spent by a task waiting for system
315 resources like cpu, synchronous block I/O completion and swapping
316 in pages. Such statistics can help in setting a task's priorities
317 relative to other tasks for cpu, io, rss limits etc.
318
319 Say N if unsure.
320
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800321config TASK_XACCT
322 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
323 depends on TASKSTATS
324 help
325 Collect extended task accounting data and send the data
326 to userland for processing over the taskstats interface.
327
328 Say N if unsure.
329
330config TASK_IO_ACCOUNTING
331 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
332 depends on TASK_XACCT
333 help
334 Collect information on the number of bytes of storage I/O which this
335 task has caused.
336
337 Say N if unsure.
338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339config AUDIT
340 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100341 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 help
343 Enable auditing infrastructure that can be used with another
344 kernel subsystem, such as SELinux (which requires this for
345 logging of avc messages output). Does not do system-call
346 auditing without CONFIG_AUDITSYSCALL.
347
348config AUDITSYSCALL
349 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000350 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 default y if SECURITY_SELINUX
352 help
353 Enable low-overhead system-call auditing infrastructure that
354 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500355 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
Eric Paris939a67f2009-12-17 20:12:06 -0500357config AUDIT_WATCH
358 def_bool y
359 depends on AUDITSYSCALL
360 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
Al Viro74c3cbe2007-07-22 08:04:18 -0400362config AUDIT_TREE
363 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400364 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500365 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400366
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000367source "kernel/irq/Kconfig"
368
Mike Travisc903ff82009-01-15 12:28:29 -0800369menu "RCU Subsystem"
370
371choice
372 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700373 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800374
Mike Travisc903ff82009-01-15 12:28:29 -0800375config TREE_RCU
376 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700377 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800378 help
379 This option selects the RCU implementation that is
380 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700381 thousands of CPUs. It also scales down nicely to
382 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800383
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700384config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700385 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700386 depends on PREEMPT
387 help
388 This option selects the RCU implementation that is
389 designed for very large SMP systems with hundreds or
390 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700391 is also required. It also scales down nicely to
392 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700393
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700394config TINY_RCU
395 bool "UP-only small-memory-footprint RCU"
396 depends on !SMP
397 help
398 This option selects the RCU implementation that is
399 designed for UP systems from which real-time response
400 is not required. This option greatly reduces the
401 memory footprint of RCU.
402
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700403config TINY_PREEMPT_RCU
404 bool "Preemptible UP-only small-memory-footprint RCU"
405 depends on !SMP && PREEMPT
406 help
407 This option selects the RCU implementation that is designed
408 for real-time UP systems. This option greatly reduces the
409 memory footprint of RCU.
410
Mike Travisc903ff82009-01-15 12:28:29 -0800411endchoice
412
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700413config PREEMPT_RCU
414 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
415 help
416 This option enables preemptible-RCU code that is common between
417 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
418
Mike Travisc903ff82009-01-15 12:28:29 -0800419config RCU_TRACE
420 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800421 help
422 This option provides tracing in RCU which presents stats
423 in debugfs for debugging RCU implementation.
424
425 Say Y here if you want to enable RCU tracing
426 Say N if you are unsure.
427
428config RCU_FANOUT
429 int "Tree-based hierarchical RCU fanout value"
430 range 2 64 if 64BIT
431 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700432 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800433 default 64 if 64BIT
434 default 32 if !64BIT
435 help
436 This option controls the fanout of hierarchical implementations
437 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700438 large numbers of CPUs. This value must be at least the fourth
439 root of NR_CPUS, which allows NR_CPUS to be insanely large.
440 The default value of RCU_FANOUT should be used for production
441 systems, but if you are stress-testing the RCU implementation
442 itself, small RCU_FANOUT values allow you to test large-system
443 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800444
445 Select a specific number if testing RCU itself.
446 Take the default if unsure.
447
448config RCU_FANOUT_EXACT
449 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700450 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800451 default n
452 help
453 This option forces use of the exact RCU_FANOUT value specified,
454 regardless of imbalances in the hierarchy. This is useful for
455 testing RCU itself, and might one day be useful on systems with
456 strong NUMA behavior.
457
458 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
459
460 Say N if unsure.
461
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800462config RCU_FAST_NO_HZ
463 bool "Accelerate last non-dyntick-idle CPU's grace periods"
464 depends on TREE_RCU && NO_HZ && SMP
465 default n
466 help
467 This option causes RCU to attempt to accelerate grace periods
468 in order to allow the final CPU to enter dynticks-idle state
469 more quickly. On the other hand, this option increases the
470 overhead of the dynticks-idle checking, particularly on systems
471 with large numbers of CPUs.
472
473 Say Y if energy efficiency is critically important, particularly
474 if you have relatively few CPUs.
475
476 Say N if you are unsure.
477
Mike Travisc903ff82009-01-15 12:28:29 -0800478config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700479 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800480 select DEBUG_FS
481 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700482 This option provides tracing for the TREE_RCU and
483 TREE_PREEMPT_RCU implementations, permitting Makefile to
484 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800485
Paul E. McKenney24278d12010-09-27 17:25:23 -0700486config RCU_BOOST
487 bool "Enable RCU priority boosting"
488 depends on RT_MUTEXES && TINY_PREEMPT_RCU
489 default n
490 help
491 This option boosts the priority of preempted RCU readers that
492 block the current preemptible RCU grace period for too long.
493 This option also prevents heavy loads from blocking RCU
494 callback invocation for all flavors of RCU.
495
496 Say Y here if you are working with real-time apps or heavy loads
497 Say N here if you are unsure.
498
499config RCU_BOOST_PRIO
500 int "Real-time priority to boost RCU readers to"
501 range 1 99
502 depends on RCU_BOOST
503 default 1
504 help
505 This option specifies the real-time priority to which preempted
506 RCU readers are to be boosted. If you are working with CPU-bound
507 real-time applications, you should specify a priority higher then
508 the highest-priority CPU-bound application.
509
510 Specify the real-time priority, or take the default if unsure.
511
512config RCU_BOOST_DELAY
513 int "Milliseconds to delay boosting after RCU grace-period start"
514 range 0 3000
515 depends on RCU_BOOST
516 default 500
517 help
518 This option specifies the time to wait after the beginning of
519 a given grace period before priority-boosting preempted RCU
520 readers blocking that grace period. Note that any RCU reader
521 blocking an expedited RCU grace period is boosted immediately.
522
523 Accept the default if unsure.
524
Mike Travisc903ff82009-01-15 12:28:29 -0800525endmenu # "RCU Subsystem"
526
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700528 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 ---help---
530 This option enables the complete Linux kernel ".config" file
531 contents to be saved in the kernel. It provides documentation
532 of which kernel options are used in a running kernel or in an
533 on-disk kernel. This information can be extracted from the kernel
534 image file with the script scripts/extract-ikconfig and used as
535 input to rebuild the current kernel or to build another kernel.
536 It can also be extracted from a running kernel by reading
537 /proc/config.gz if enabled (below).
538
539config IKCONFIG_PROC
540 bool "Enable access to .config through /proc/config.gz"
541 depends on IKCONFIG && PROC_FS
542 ---help---
543 This option enables access to the kernel configuration file
544 through /proc/config.gz.
545
Alistair John Strachan794543a2007-05-08 00:31:15 -0700546config LOG_BUF_SHIFT
547 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
548 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700549 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700550 help
551 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700552 Examples:
553 17 => 128 KB
554 16 => 64 KB
555 15 => 32 KB
556 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700557 13 => 8 KB
558 12 => 4 KB
559
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800560#
561# Architectures with an unreliable sched_clock() should select this:
562#
563config HAVE_UNSTABLE_SCHED_CLOCK
564 bool
565
Li Zefan23964d22009-01-15 13:50:58 -0800566menuconfig CGROUPS
567 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800568 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700569 help
Li Zefan23964d22009-01-15 13:50:58 -0800570 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800571 use with process control subsystems such as Cpusets, CFS, memory
572 controls or device isolation.
573 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800574 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800575 - Documentation/cgroups/ (features for grouping, isolation
576 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700577
578 Say N if unsure.
579
Li Zefan23964d22009-01-15 13:50:58 -0800580if CGROUPS
581
Paul Menage006cb992007-10-18 23:39:43 -0700582config CGROUP_DEBUG
583 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700584 default n
Paul Menage006cb992007-10-18 23:39:43 -0700585 help
586 This option enables a simple cgroup subsystem that
587 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800588 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700589
Li Zefan23964d22009-01-15 13:50:58 -0800590 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700591
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700592config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800593 bool "Namespace cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800594 help
595 Provides a simple namespace cgroup subsystem to
596 provide hierarchical naming of sets of namespaces,
597 for instance virtual servers and checkpoint/restart
598 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -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 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800907 help
908 Enabling this option will pass "-Os" instead of "-O2" to gcc
909 resulting in a smaller kernel.
910
jkacur775a7222008-07-16 00:31:16 +0200911 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800912
Randy Dunlap08470622006-09-30 23:28:13 -0700913config SYSCTL
914 bool
915
Randy Dunlapb943c462009-03-10 12:55:46 -0700916config ANON_INODES
917 bool
918
David Rientjes6a108a12011-01-20 14:44:16 -0800919menuconfig EXPERT
920 bool "Configure standard kernel features (expert users)"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 help
922 This option allows certain base kernel options and settings
923 to be disabled or tweaked. This is for specialized
924 environments which can tolerate a "non-standard" kernel.
925 Only use this if you really know what you are doing.
926
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700927config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800928 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700929 depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700930 default y
931 help
932 This enables the legacy 16-bit UID syscall wrappers.
933
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700934config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800935 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800936 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800937 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700938 select SYSCTL
939 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800940 sys_sysctl uses binary paths that have been found challenging
941 to properly maintain and use. The interface in /proc/sys
942 using paths with ascii names is now the primary path to this
943 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700944
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800945 Almost nothing using the binary sysctl interface so if you are
946 trying to save some space it is probably safe to disable this,
947 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700948
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800949 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700950
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800952 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 default y
954 help
955 Say Y here to let the kernel print out symbolic crash information and
956 symbolic stack backtraces. This increases the size of the kernel
957 somewhat, as all symbols have to be loaded into the kernel image.
958
959config KALLSYMS_ALL
960 bool "Include all symbols in kallsyms"
961 depends on DEBUG_KERNEL && KALLSYMS
962 help
963 Normally kallsyms only contains the symbols of functions, for nicer
964 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200965 symbols too: say Y here to include all symbols, if you need them
966 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
968 Say N.
969
970config KALLSYMS_EXTRA_PASS
971 bool "Do an extra kallsyms pass"
972 depends on KALLSYMS
973 help
974 If kallsyms is not working correctly, the build will fail with
975 inconsistent kallsyms data. If that occurs, log a bug report and
976 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
977 Always say N here unless you find a bug in kallsyms, which must be
978 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
979 you wait for kallsyms to be fixed.
980
Matt Mackalld59745c2005-05-01 08:59:02 -0700981
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800982config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -0800983 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800984 default y
985 help
986 This option is provided for the case where no hotplug or uevent
987 capabilities is wanted by the kernel. You should only consider
988 disabling this option for embedded systems that do not use modules, a
989 dynamic /dev tree, or dynamic device discovery. Just say Y.
990
Matt Mackalld59745c2005-05-01 08:59:02 -0700991config PRINTK
992 default y
David Rientjes6a108a12011-01-20 14:44:16 -0800993 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -0700994 help
995 This option enables normal printk support. Removing it
996 eliminates most of the message strings from the kernel image
997 and makes the kernel more or less silent. As this makes it
998 very difficult to diagnose system problems, saying N here is
999 strongly discouraged.
1000
Matt Mackallc8538a72005-05-01 08:59:01 -07001001config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001002 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001003 default y
1004 help
1005 Disabling this option eliminates support for BUG and WARN, reducing
1006 the size of your kernel image and potentially quietly ignoring
1007 numerous fatal conditions. You should only consider disabling this
1008 option for embedded systems with no facilities for reporting errors.
1009 Just say Y.
1010
Matt Mackall708e9a72006-01-08 01:05:25 -08001011config ELF_CORE
1012 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001013 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001014 help
1015 Enable support for generating core dumps. Disabling saves about 4k.
1016
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001017config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001018 bool "Enable PC-Speaker support" if EXPERT
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001019 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
1020 default y
1021 help
1022 This option allows to disable the internal PC-Speaker
1023 support, saving some memory.
1024
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025config BASE_FULL
1026 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001027 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 help
1029 Disabling this option reduces the size of miscellaneous core
1030 kernel data structures. This saves memory on small machines,
1031 but may reduce performance.
1032
1033config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001034 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001036 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 help
1038 Disabling this option will cause the kernel to be built without
1039 support for "fast userspace mutexes". The resulting kernel may not
1040 run glibc-based applications correctly.
1041
1042config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001043 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001045 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 help
1047 Disabling this option will cause the kernel to be built without
1048 support for epoll family of system calls.
1049
Davide Libenzifba2afa2007-05-10 22:23:13 -07001050config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001051 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001052 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001053 default y
1054 help
1055 Enable the signalfd() system call that allows to receive signals
1056 on a file descriptor.
1057
1058 If unsure, say Y.
1059
Davide Libenzib215e282007-05-10 22:23:16 -07001060config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001061 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001062 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001063 default y
1064 help
1065 Enable the timerfd() system call that allows to receive timer
1066 events on a file descriptor.
1067
1068 If unsure, say Y.
1069
Davide Libenzie1ad7462007-05-10 22:23:19 -07001070config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001071 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001072 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001073 default y
1074 help
1075 Enable the eventfd() system call that allows to receive both
1076 kernel notification (ie. KAIO) or userspace notifications.
1077
1078 If unsure, say Y.
1079
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001081 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 default y
1083 depends on MMU
1084 help
1085 The shmem is an internal filesystem used to manage shared memory.
1086 It is backed by swap and manages resource limits. It is also exported
1087 to userspace as tmpfs if TMPFS is enabled. Disabling this
1088 option replaces shmem and tmpfs with the much simpler ramfs code,
1089 which may be appropriate on small systems without swap.
1090
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001091config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001092 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001093 default y
1094 help
1095 This option enables POSIX asynchronous I/O which may by used
1096 by some high performance threaded applications. Disabling
1097 this option saves about 7k.
1098
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001099config EMBEDDED
1100 bool "Embedded system"
1101 select EXPERT
1102 help
1103 This option should be enabled if compiling the kernel for
1104 an embedded system so certain expert options are available
1105 for configuration.
1106
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001107config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001108 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001109 help
1110 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001111
Peter Zijlstra906010b2009-09-21 16:08:49 +02001112config PERF_USE_VMALLOC
1113 bool
1114 help
1115 See tools/perf/design.txt for details
1116
Ingo Molnar57c0c152009-09-21 12:20:38 +02001117menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001118
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001119config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001120 bool "Kernel performance events and counters"
1121 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001122 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001123 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001124 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001125 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001126 Enable kernel support for various performance events provided
1127 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001128
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001129 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001130 use of generic tracepoints.
1131
1132 Most modern CPUs support performance events via performance
1133 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001134 types of hw events: such as instructions executed, cachemisses
1135 suffered, or branches mis-predicted - without slowing down the
1136 kernel or applications. These registers can also trigger interrupts
1137 when a threshold number of events have passed - and can thus be
1138 used to profile the code that runs on that CPU.
1139
Ingo Molnar57c0c152009-09-21 12:20:38 +02001140 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001141 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001142 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001143 provides per task and per CPU counters, and it provides event
1144 capabilities on top of those.
1145
1146 Say Y if unsure.
1147
Ingo Molnar57c0c152009-09-21 12:20:38 +02001148config PERF_COUNTERS
1149 bool "Kernel performance counters (old config option)"
1150 depends on HAVE_PERF_EVENTS
1151 help
1152 This config has been obsoleted by the PERF_EVENTS
1153 config option - please see that one for details.
1154
1155 It has no effect on the kernel whether you enable
1156 it or not, it is a compatibility placeholder.
1157
1158 Say N if unsure.
1159
Peter Zijlstra906010b2009-09-21 16:08:49 +02001160config DEBUG_PERF_USE_VMALLOC
1161 default n
1162 bool "Debug: use vmalloc to back perf mmap() buffers"
1163 depends on PERF_EVENTS && DEBUG_KERNEL
1164 select PERF_USE_VMALLOC
1165 help
1166 Use vmalloc memory to back perf mmap() buffers.
1167
1168 Mostly useful for debugging the vmalloc code on platforms
1169 that don't require it.
1170
1171 Say N if unsure.
1172
Thomas Gleixner0793a612008-12-04 20:12:29 +01001173endmenu
1174
Christoph Lameterf8891e52006-06-30 01:55:45 -07001175config VM_EVENT_COUNTERS
1176 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001177 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001178 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001179 VM event counters are needed for event counts to be shown.
1180 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001181 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001182 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001183
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001184config PCI_QUIRKS
1185 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001186 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001187 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001188 help
1189 This enables workarounds for various PCI chipset
1190 bugs/quirks. Disable this only if your target machine is
1191 unaffected by PCI quirks.
1192
Christoph Lameter41ecc552007-05-09 02:32:44 -07001193config SLUB_DEBUG
1194 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001195 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001196 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001197 help
1198 SLUB has extensive debug support features. Disabling these can
1199 result in significant savings in code size. This also disables
1200 SLUB sysfs support. /sys/slab will not exist and there will be
1201 no support for cache validation etc.
1202
Randy Dunlapb943c462009-03-10 12:55:46 -07001203config COMPAT_BRK
1204 bool "Disable heap randomization"
1205 default y
1206 help
1207 Randomizing heap placement makes heap exploits harder, but it
1208 also breaks ancient binaries (including anything libc5 based).
1209 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001210 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001211 /proc/sys/kernel/randomize_va_space to 2.
1212
1213 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1214
Christoph Lameter81819f02007-05-06 14:49:36 -07001215choice
1216 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001217 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001218 help
1219 This option allows to select a slab allocator.
1220
1221config SLAB
1222 bool "SLAB"
1223 help
1224 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001225 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001226 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001227
1228config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001229 bool "SLUB (Unqueued Allocator)"
1230 help
1231 SLUB is a slab allocator that minimizes cache line usage
1232 instead of managing queues of cached objects (SLAB approach).
1233 Per cpu caching is realized using slabs of objects instead
1234 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001235 and has enhanced diagnostics. SLUB is the default choice for
1236 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001237
1238config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001239 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001240 bool "SLOB (Simple Allocator)"
1241 help
Matt Mackall37291452008-02-04 22:29:38 -08001242 SLOB replaces the stock allocator with a drastically simpler
1243 allocator. SLOB is generally more space efficient but
1244 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001245
1246endchoice
1247
Jie Zhangea637632009-12-14 18:00:02 -08001248config MMAP_ALLOW_UNINITIALIZED
1249 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001250 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001251 default n
1252 help
1253 Normally, and according to the Linux spec, anonymous memory obtained
1254 from mmap() has it's contents cleared before it is passed to
1255 userspace. Enabling this config option allows you to request that
1256 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1257 providing a huge performance boost. If this option is not enabled,
1258 then the flag will be ignored.
1259
1260 This is taken advantage of by uClibc's malloc(), and also by
1261 ELF-FDPIC binfmt's brk and stack allocator.
1262
1263 Because of the obvious security issues, this option should only be
1264 enabled on embedded devices where you control what is run in
1265 userspace. Since that isn't generally a problem on no-MMU systems,
1266 it is normally safe to say Y here.
1267
1268 See Documentation/nommu-mmap.txt for more information.
1269
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001270config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001271 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001272 help
1273 Say Y here to enable the extended profiling support mechanisms used
1274 by profilers such as OProfile.
1275
Ingo Molnar5f87f112008-07-23 14:15:22 +02001276#
1277# Place an empty function call at each tracepoint site. Can be
1278# dynamically changed for a probe function.
1279#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001280config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001281 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001282
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001283source "arch/Kconfig"
1284
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285endmenu # General setup
1286
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001287config HAVE_GENERIC_DMA_COHERENT
1288 bool
1289 default n
1290
Linus Torvalds158a9622008-01-02 13:04:48 -08001291config SLABINFO
1292 bool
1293 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001294 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001295 default y
1296
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001297config RT_MUTEXES
1298 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300config BASE_SMALL
1301 int
1302 default 0 if BASE_FULL
1303 default 1 if !BASE_FULL
1304
Jan Engelhardt66da5732007-07-15 23:39:29 -07001305menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 bool "Enable loadable module support"
1307 help
1308 Kernel modules are small pieces of compiled code which can
1309 be inserted in the running kernel, rather than being
1310 permanently built into the kernel. You use the "modprobe"
1311 tool to add (and sometimes remove) them. If you say Y here,
1312 many parts of the kernel can be built as modules (by
1313 answering M instead of Y where indicated): this is most
1314 useful for infrequently used options which are not required
1315 for booting. For more information, see the man pages for
1316 modprobe, lsmod, modinfo, insmod and rmmod.
1317
1318 If you say Y here, you will need to run "make
1319 modules_install" to put the modules under /lib/modules/
1320 where modprobe can find them (you may need to be root to do
1321 this).
1322
1323 If unsure, say Y.
1324
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001325if MODULES
1326
Linus Torvalds826e4502008-05-04 17:04:16 -07001327config MODULE_FORCE_LOAD
1328 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001329 default n
1330 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001331 Allow loading of modules without version information (ie. modprobe
1332 --force). Forced module loading sets the 'F' (forced) taint flag and
1333 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001334
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335config MODULE_UNLOAD
1336 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 help
1338 Without this option you will not be able to unload any
1339 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001340 anyway), which makes your kernel smaller, faster
1341 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342
1343config MODULE_FORCE_UNLOAD
1344 bool "Forced module unloading"
1345 depends on MODULE_UNLOAD && EXPERIMENTAL
1346 help
1347 This option allows you to force a module to unload, even if the
1348 kernel believes it is unsafe: the kernel will remove the module
1349 without waiting for anyone to stop using it (using the -f option to
1350 rmmod). This is mainly for kernel developers and desperate users.
1351 If unsure, say N.
1352
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001354 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 help
1356 Usually, you have to use modules compiled with your kernel.
1357 Saying Y here makes it sometimes possible to use modules
1358 compiled for different kernels, by adding enough information
1359 to the modules to (hopefully) spot any changes which would
1360 make them incompatible with the kernel you are running. If
1361 unsure, say N.
1362
1363config MODULE_SRCVERSION_ALL
1364 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 help
1366 Modules which contain a MODULE_VERSION get an extra "srcversion"
1367 field inserted into their modinfo section, which contains a
1368 sum of the source files which made it. This helps maintainers
1369 see exactly which source was used to build a module (since
1370 others sometimes change the module source without updating
1371 the version). With this option, such a "srcversion" field
1372 will be created for all modules. If unsure, say N.
1373
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001374endif # MODULES
1375
Rusty Russell98a79d62008-12-13 21:19:41 +10301376config INIT_ALL_POSSIBLE
1377 bool
1378 help
1379 Back when each arch used to define their own cpu_online_map and
1380 cpu_possible_map, some of them chose to initialize cpu_possible_map
1381 with all 1s, and others with all 0s. When they were centralised,
1382 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001383 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301384
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385config STOP_MACHINE
1386 bool
1387 default y
1388 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1389 help
1390 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001391
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001392source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001393
1394config PREEMPT_NOTIFIERS
1395 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001396
Steffen Klassert16295be2010-01-06 19:47:10 +11001397config PADATA
1398 depends on SMP
1399 bool
1400
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001401source "kernel/Kconfig.locks"