blob: 43298f9810fba87bdf0083ac1fa5401b0819c4cb [file] [log] [blame]
Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670ea2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
Al Boldiff0cfc62007-07-31 00:39:23 -070030menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32config EXPERIMENTAL
33 bool "Prompt for development and/or incomplete code/drivers"
34 ---help---
35 Some of the various things that Linux supports (such as network
36 drivers, file systems, network protocols, etc.) can be in a state
37 of development where the functionality, stability, or the level of
38 testing is not yet high enough for general use. This is usually
39 known as the "alpha-test" phase among developers. If a feature is
40 currently in alpha-test, then the developers usually discourage
41 uninformed widespread use of this feature by the general public to
42 avoid "Why doesn't this work?" type mail messages. However, active
43 testing and use of these systems is welcomed. Just be aware that it
44 may not meet the normal level of reliability or it may fail to work
45 in some special cases. Detailed bug reports from people familiar
46 with the kernel internals are usually welcomed by the developers
47 (before submitting bug reports, please read the documents
48 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
49 <file:Documentation/BUG-HUNTING>, and
50 <file:Documentation/oops-tracing.txt> in the kernel source).
51
52 This option will also make obsoleted drivers available. These are
53 drivers that have been replaced by something else, and/or are
54 scheduled to be removed in a future kernel release.
55
56 Unless you intend to help test and develop a feature or driver that
57 falls into this category, or you have a situation that requires
58 using these features, you should probably say N here, which will
59 cause the configurator to present you with fewer choices. If
60 you say Y here, you will be offered the choice of using features or
61 drivers that are currently considered to be in the alpha-test phase.
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063config BROKEN
64 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66config BROKEN_ON_SMP
67 bool
68 depends on BROKEN || !SMP
69 default y
70
Linus Torvalds1da177e2005-04-16 15:20:36 -070071config INIT_ENV_ARG_LIMIT
72 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070073 default 32 if !UML
74 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080076 Maximum of each of the number of arguments and environment
77 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Roland McGrath84336462009-12-21 16:24:06 -080080config CROSS_COMPILE
81 string "Cross-compiler tool prefix"
82 help
83 Same as running 'make CROSS_COMPILE=prefix-' but stored for
84 default make runs in this kernel build directory. You don't
85 need to set this unless you want the configured kernel build
86 directory to select the cross-compiler automatically.
87
Linus Torvalds1da177e2005-04-16 15:20:36 -070088config LOCALVERSION
89 string "Local version - append to kernel release"
90 help
91 Append an extra string to the end of your kernel version.
92 This will show up when you type uname, for example.
93 The string you set here will be appended after the contents of
94 any files with a filename matching localversion* in your
95 object and source tree, in that order. Your total string can
96 be a maximum of 64 characters.
97
Ryan Andersonaaebf432005-07-31 04:57:49 -040098config LOCALVERSION_AUTO
99 bool "Automatically append version information to the version string"
100 default y
101 help
102 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200103 release tree by looking for git tags that belong to the current
104 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400105
106 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200107 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200109 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400110
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200111 (The actual string used here is the first eight characters produced
112 by running the command:
113
114 $ git rev-parse --verify HEAD
115
116 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400117
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800118config HAVE_KERNEL_GZIP
119 bool
120
121config HAVE_KERNEL_BZIP2
122 bool
123
124config HAVE_KERNEL_LZMA
125 bool
126
Lasse Collin3ebe1242011-01-12 17:01:23 -0800127config HAVE_KERNEL_XZ
128 bool
129
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800130config HAVE_KERNEL_LZO
131 bool
132
Alain Knaff30d65db2009-01-04 22:46:17 +0100133choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800134 prompt "Kernel compression mode"
135 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800136 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800137 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100138 The linux kernel is a kind of self-extracting executable.
139 Several compression algorithms are available, which differ
140 in efficiency, compression and decompression speed.
141 Compression speed is only relevant when building a kernel.
142 Decompression speed is relevant at each boot.
143
144 If you have any problems with bzip2 or lzma compressed
145 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
146 version of this functionality (bzip2 only), for 2.4, was
147 supplied by Christian Ludwig)
148
149 High compression options are mostly useful for users, who
150 are low on disk space (embedded systems), but for whom ram
151 size matters less.
152
153 If in doubt, select 'gzip'
154
155config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800156 bool "Gzip"
157 depends on HAVE_KERNEL_GZIP
158 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800159 The old and tried gzip compression. It provides a good balance
160 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100161
162config KERNEL_BZIP2
163 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800164 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100165 help
166 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 Decompression speed is slowest among the three. The kernel
168 size is about 10% smaller with bzip2, in comparison to gzip.
169 Bzip2 uses a large amount of memory. For modern kernels you
170 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100171
172config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800173 bool "LZMA"
174 depends on HAVE_KERNEL_LZMA
175 help
176 The most recent compression algorithm.
177 Its ratio is best, decompression speed is between the other
178 two. Compression is slowest. The kernel size is about 33%
179 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100180
Lasse Collin3ebe1242011-01-12 17:01:23 -0800181config KERNEL_XZ
182 bool "XZ"
183 depends on HAVE_KERNEL_XZ
184 help
185 XZ uses the LZMA2 algorithm and instruction set specific
186 BCJ filters which can improve compression ratio of executable
187 code. The size of the kernel is about 30% smaller with XZ in
188 comparison to gzip. On architectures for which there is a BCJ
189 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
190 will create a few percent smaller kernel than plain LZMA.
191
192 The speed is about the same as with LZMA: The decompression
193 speed of XZ is better than that of bzip2 but worse than gzip
194 and LZO. Compression is slow.
195
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800196config KERNEL_LZO
197 bool "LZO"
198 depends on HAVE_KERNEL_LZO
199 help
200 Its compression ratio is the poorest among the 4. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200201 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800202 (both compression and decompression) is the fastest.
203
Alain Knaff30d65db2009-01-04 22:46:17 +0100204endchoice
205
Josh Triplettbd5dc172011-06-15 15:08:28 -0700206config DEFAULT_HOSTNAME
207 string "Default hostname"
208 default "(none)"
209 help
210 This option determines the default system hostname before userspace
211 calls sethostname(2). The kernel traditionally uses "(none)" here,
212 but you may wish to use a different default here to make a minimal
213 system more usable with less configuration.
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215config SWAP
216 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200217 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 default y
219 help
220 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100221 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 used to provide more virtual memory than the actual RAM present
223 in your computer. If unsure say Y.
224
225config SYSVIPC
226 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 ---help---
228 Inter Process Communication is a suite of library functions and
229 system calls which let processes (running programs) synchronize and
230 exchange information. It is generally considered to be a good thing,
231 and some programs won't run unless you say Y here. In particular, if
232 you want to run the DOS emulator dosemu under Linux (read the
233 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
234 you'll need to say Y here.
235
236 You can find documentation about IPC with "info ipc" and also in
237 section 6.4 of the Linux Programmer's Guide, available from
238 <http://www.tldp.org/guides.html>.
239
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800240config SYSVIPC_SYSCTL
241 bool
242 depends on SYSVIPC
243 depends on SYSCTL
244 default y
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246config POSIX_MQUEUE
247 bool "POSIX Message Queues"
248 depends on NET && EXPERIMENTAL
249 ---help---
250 POSIX variant of message queues is a part of IPC. In POSIX message
251 queues every message has a priority which decides about succession
252 of receiving it by a process. If you want to compile and run
253 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200254 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 POSIX message queues are visible as a filesystem called 'mqueue'
257 and can be mounted somewhere if you want to do filesystem
258 operations on message queues.
259
260 If unsure, say Y.
261
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700262config POSIX_MQUEUE_SYSCTL
263 bool
264 depends on POSIX_MQUEUE
265 depends on SYSCTL
266 default y
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268config BSD_PROCESS_ACCT
269 bool "BSD Process Accounting"
270 help
271 If you say Y here, a user level program will be able to instruct the
272 kernel (via a special system call) to write process accounting
273 information to a file: whenever a process exits, information about
274 that process will be appended to the file by the kernel. The
275 information includes things such as creation time, owning user,
276 command name, memory usage, controlling terminal etc. (the complete
277 list is in the struct acct in <file:include/linux/acct.h>). It is
278 up to the user level program to do useful things with this
279 information. This is generally a good idea, so say Y.
280
281config BSD_PROCESS_ACCT_V3
282 bool "BSD Process Accounting version 3 file format"
283 depends on BSD_PROCESS_ACCT
284 default n
285 help
286 If you say Y here, the process accounting information is written
287 in a new file format that also logs the process IDs of each
288 process and it's parent. Note that this file format is incompatible
289 with previous v0/v1/v2 file formats, so you will need updated tools
290 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300291 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530293config FHANDLE
294 bool "open by fhandle syscalls"
295 select EXPORTFS
296 help
297 If you say Y here, a user level program will be able to map
298 file names to handle and then later use the handle for
299 different file system operations. This is useful in implementing
300 userspace file servers, which now track files using handles instead
301 of names. The handle would remain the same even if file names
302 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
303 syscalls.
304
Shailabh Nagarc7572492006-07-14 00:24:40 -0700305config TASKSTATS
306 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
307 depends on NET
308 default n
309 help
310 Export selected statistics for tasks/processes through the
311 generic netlink interface. Unlike BSD process accounting, the
312 statistics are available during the lifetime of tasks/processes as
313 responses to commands. Like BSD accounting, they are sent to user
314 space on task exit.
315
316 Say N if unsure.
317
Shailabh Nagarca74e922006-07-14 00:24:36 -0700318config TASK_DELAY_ACCT
319 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700320 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700321 help
322 Collect information on time spent by a task waiting for system
323 resources like cpu, synchronous block I/O completion and swapping
324 in pages. Such statistics can help in setting a task's priorities
325 relative to other tasks for cpu, io, rss limits etc.
326
327 Say N if unsure.
328
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800329config TASK_XACCT
330 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
331 depends on TASKSTATS
332 help
333 Collect extended task accounting data and send the data
334 to userland for processing over the taskstats interface.
335
336 Say N if unsure.
337
338config TASK_IO_ACCOUNTING
339 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
340 depends on TASK_XACCT
341 help
342 Collect information on the number of bytes of storage I/O which this
343 task has caused.
344
345 Say N if unsure.
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347config AUDIT
348 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100349 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 help
351 Enable auditing infrastructure that can be used with another
352 kernel subsystem, such as SELinux (which requires this for
353 logging of avc messages output). Does not do system-call
354 auditing without CONFIG_AUDITSYSCALL.
355
356config AUDITSYSCALL
357 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000358 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 default y if SECURITY_SELINUX
360 help
361 Enable low-overhead system-call auditing infrastructure that
362 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500363 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Eric Paris939a67f2009-12-17 20:12:06 -0500365config AUDIT_WATCH
366 def_bool y
367 depends on AUDITSYSCALL
368 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
Al Viro74c3cbe2007-07-22 08:04:18 -0400370config AUDIT_TREE
371 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400372 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500373 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400374
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000375source "kernel/irq/Kconfig"
376
Mike Travisc903ff82009-01-15 12:28:29 -0800377menu "RCU Subsystem"
378
379choice
380 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700381 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800382
Mike Travisc903ff82009-01-15 12:28:29 -0800383config TREE_RCU
384 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700385 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800386 help
387 This option selects the RCU implementation that is
388 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700389 thousands of CPUs. It also scales down nicely to
390 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800391
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700392config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700393 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700394 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700395 help
396 This option selects the RCU implementation that is
397 designed for very large SMP systems with hundreds or
398 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700399 is also required. It also scales down nicely to
400 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700401
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700402config TINY_RCU
403 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700404 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700405 help
406 This option selects the RCU implementation that is
407 designed for UP systems from which real-time response
408 is not required. This option greatly reduces the
409 memory footprint of RCU.
410
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700411config TINY_PREEMPT_RCU
412 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700413 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700414 help
415 This option selects the RCU implementation that is designed
416 for real-time UP systems. This option greatly reduces the
417 memory footprint of RCU.
418
Mike Travisc903ff82009-01-15 12:28:29 -0800419endchoice
420
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700421config PREEMPT_RCU
422 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
423 help
424 This option enables preemptible-RCU code that is common between
425 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
426
Mike Travisc903ff82009-01-15 12:28:29 -0800427config RCU_TRACE
428 bool "Enable tracing for RCU"
Mike Travisc903ff82009-01-15 12:28:29 -0800429 help
430 This option provides tracing in RCU which presents stats
431 in debugfs for debugging RCU implementation.
432
433 Say Y here if you want to enable RCU tracing
434 Say N if you are unsure.
435
436config RCU_FANOUT
437 int "Tree-based hierarchical RCU fanout value"
438 range 2 64 if 64BIT
439 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700440 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800441 default 64 if 64BIT
442 default 32 if !64BIT
443 help
444 This option controls the fanout of hierarchical implementations
445 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700446 large numbers of CPUs. This value must be at least the fourth
447 root of NR_CPUS, which allows NR_CPUS to be insanely large.
448 The default value of RCU_FANOUT should be used for production
449 systems, but if you are stress-testing the RCU implementation
450 itself, small RCU_FANOUT values allow you to test large-system
451 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800452
453 Select a specific number if testing RCU itself.
454 Take the default if unsure.
455
456config RCU_FANOUT_EXACT
457 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700458 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800459 default n
460 help
461 This option forces use of the exact RCU_FANOUT value specified,
462 regardless of imbalances in the hierarchy. This is useful for
463 testing RCU itself, and might one day be useful on systems with
464 strong NUMA behavior.
465
466 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
467
468 Say N if unsure.
469
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800470config RCU_FAST_NO_HZ
471 bool "Accelerate last non-dyntick-idle CPU's grace periods"
472 depends on TREE_RCU && NO_HZ && SMP
473 default n
474 help
475 This option causes RCU to attempt to accelerate grace periods
476 in order to allow the final CPU to enter dynticks-idle state
477 more quickly. On the other hand, this option increases the
478 overhead of the dynticks-idle checking, particularly on systems
479 with large numbers of CPUs.
480
481 Say Y if energy efficiency is critically important, particularly
482 if you have relatively few CPUs.
483
484 Say N if you are unsure.
485
Mike Travisc903ff82009-01-15 12:28:29 -0800486config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700487 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800488 select DEBUG_FS
489 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700490 This option provides tracing for the TREE_RCU and
491 TREE_PREEMPT_RCU implementations, permitting Makefile to
492 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800493
Paul E. McKenney24278d12010-09-27 17:25:23 -0700494config RCU_BOOST
495 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800496 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700497 default n
498 help
499 This option boosts the priority of preempted RCU readers that
500 block the current preemptible RCU grace period for too long.
501 This option also prevents heavy loads from blocking RCU
502 callback invocation for all flavors of RCU.
503
504 Say Y here if you are working with real-time apps or heavy loads
505 Say N here if you are unsure.
506
507config RCU_BOOST_PRIO
508 int "Real-time priority to boost RCU readers to"
509 range 1 99
510 depends on RCU_BOOST
511 default 1
512 help
513 This option specifies the real-time priority to which preempted
514 RCU readers are to be boosted. If you are working with CPU-bound
515 real-time applications, you should specify a priority higher then
516 the highest-priority CPU-bound application.
517
518 Specify the real-time priority, or take the default if unsure.
519
520config RCU_BOOST_DELAY
521 int "Milliseconds to delay boosting after RCU grace-period start"
522 range 0 3000
523 depends on RCU_BOOST
524 default 500
525 help
526 This option specifies the time to wait after the beginning of
527 a given grace period before priority-boosting preempted RCU
528 readers blocking that grace period. Note that any RCU reader
529 blocking an expedited RCU grace period is boosted immediately.
530
531 Accept the default if unsure.
532
Mike Travisc903ff82009-01-15 12:28:29 -0800533endmenu # "RCU Subsystem"
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700536 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 ---help---
538 This option enables the complete Linux kernel ".config" file
539 contents to be saved in the kernel. It provides documentation
540 of which kernel options are used in a running kernel or in an
541 on-disk kernel. This information can be extracted from the kernel
542 image file with the script scripts/extract-ikconfig and used as
543 input to rebuild the current kernel or to build another kernel.
544 It can also be extracted from a running kernel by reading
545 /proc/config.gz if enabled (below).
546
547config IKCONFIG_PROC
548 bool "Enable access to .config through /proc/config.gz"
549 depends on IKCONFIG && PROC_FS
550 ---help---
551 This option enables access to the kernel configuration file
552 through /proc/config.gz.
553
Alistair John Strachan794543a2007-05-08 00:31:15 -0700554config LOG_BUF_SHIFT
555 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
556 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700557 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700558 help
559 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700560 Examples:
561 17 => 128 KB
562 16 => 64 KB
563 15 => 32 KB
564 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700565 13 => 8 KB
566 12 => 4 KB
567
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800568#
569# Architectures with an unreliable sched_clock() should select this:
570#
571config HAVE_UNSTABLE_SCHED_CLOCK
572 bool
573
Li Zefan23964d22009-01-15 13:50:58 -0800574menuconfig CGROUPS
575 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800576 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700577 help
Li Zefan23964d22009-01-15 13:50:58 -0800578 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800579 use with process control subsystems such as Cpusets, CFS, memory
580 controls or device isolation.
581 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800582 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800583 - Documentation/cgroups/ (features for grouping, isolation
584 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700585
586 Say N if unsure.
587
Li Zefan23964d22009-01-15 13:50:58 -0800588if CGROUPS
589
Paul Menage006cb992007-10-18 23:39:43 -0700590config CGROUP_DEBUG
591 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700592 default n
Paul Menage006cb992007-10-18 23:39:43 -0700593 help
594 This option enables a simple cgroup subsystem that
595 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800596 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700597
Li Zefan23964d22009-01-15 13:50:58 -0800598 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700599
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700600config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800601 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800602 help
603 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700604 cgroup.
605
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700606config CGROUP_DEVICE
607 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700608 help
609 Provides a cgroup implementing whitelists for devices which
610 a process in the cgroup can mknod or open.
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612config CPUSETS
613 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700615 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 allow dynamically partitioning a system into sets of CPUs and
617 Memory Nodes and assigning tasks to run only within those sets.
618 This is primarily useful on large SMP or NUMA systems.
619
620 Say N if unsure.
621
Li Zefan23964d22009-01-15 13:50:58 -0800622config PROC_PID_CPUSET
623 bool "Include legacy /proc/<pid>/cpuset file"
624 depends on CPUSETS
625 default y
626
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100627config CGROUP_CPUACCT
628 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100629 help
630 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800631 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100632
Pavel Emelianove552b662008-02-07 00:13:49 -0800633config RESOURCE_COUNTERS
634 bool "Resource counters"
635 help
636 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800637 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800638
Balbir Singh00f0b822008-03-04 14:28:39 -0800639config CGROUP_MEM_RES_CTLR
640 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700641 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700642 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800643 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700644 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100645 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800646
647 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700648 associated with each page of memory in the system. By this,
649 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
650 usage tracking struct at boot. Total amount of this is printed out
651 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800652
653 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700654 sure you need the memory resource controller. Even when you enable
655 this, you can set "cgroup_disable=memory" at your boot option to
656 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800657 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800658
Balbir Singhcf475ad2008-04-29 01:00:16 -0700659 This config option also selects MM_OWNER config option, which
660 could in turn add some fork/exit overhead.
661
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800662config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700663 bool "Memory Resource Controller Swap Extension"
664 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800665 help
666 Add swap management feature to memory resource controller. When you
667 enable this, you can limit mem+swap usage per cgroup. In other words,
668 when you disable this, memory resource controller has no cares to
669 usage of swap...a process can exhaust all of the swap. This extension
670 is useful when you want to avoid exhaustion swap but this itself
671 adds more overheads and consumes memory for remembering information.
672 Especially if you use 32bit system or small memory system, please
673 be careful about enabling this. When memory resource controller
674 is disabled by boot option, this will be automatically disabled and
675 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700676 if boot option "swapaccount=0" 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
WANG Cong00a66d22011-07-25 17:12:12 -0700691 then swapaccount=0 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
Paul Turnerab84d312011-07-21 09:43:28 -0700718config CFS_BANDWIDTH
719 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
720 depends on EXPERIMENTAL
721 depends on FAIR_GROUP_SCHED
722 default n
723 help
724 This option allows users to define CPU bandwidth rates (limits) for
725 tasks running within the fair group scheduler. Groups with no limit
726 set are considered to be unconstrained and will run with no
727 restriction.
728 See tip/Documentation/scheduler/sched-bwc.txt for more information.
729
Dhaval Giani7c941432010-01-20 13:26:18 +0100730config RT_GROUP_SCHED
731 bool "Group scheduling for SCHED_RR/FIFO"
732 depends on EXPERIMENTAL
733 depends on CGROUP_SCHED
734 default n
735 help
736 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800737 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100738 schedule realtime tasks for non-root users until you allocate
739 realtime bandwidth for them.
740 See Documentation/scheduler/sched-rt-group.txt for more information.
741
742endif #CGROUP_SCHED
743
Vivek Goyalafc24d42010-04-26 19:27:56 +0200744config BLK_CGROUP
745 tristate "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700746 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200747 default n
748 ---help---
749 Generic block IO controller cgroup interface. This is the common
750 cgroup interface which should be used by various IO controlling
751 policies.
752
753 Currently, CFQ IO scheduler uses it to recognize task groups and
754 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400755 to such task groups. It is also used by bio throttling logic in
756 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200757
758 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400759 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000760 enabling proportional weight division of disk bandwidth in CFQ, set
761 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000762 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200763
764 See Documentation/cgroups/blkio-controller.txt for more information.
765
766config DEBUG_BLK_CGROUP
767 bool "Enable Block IO controller debugging"
768 depends on BLK_CGROUP
769 default n
770 ---help---
771 Enable some debugging help. Currently it exports additional stat
772 files in a cgroup which can be useful for debugging.
773
Li Zefan23964d22009-01-15 13:50:58 -0800774endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800775
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700776menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800777 bool "Namespaces support" if EXPERT
778 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800779 help
780 Provides the way to make tasks work with different objects using
781 the same id. For example same IPC id may refer to different objects
782 or same user id or pid may refer to different tasks when used in
783 different namespaces.
784
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700785if NAMESPACES
786
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800787config UTS_NS
788 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700789 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800790 help
791 In this namespace tasks see different info provided with the
792 uname() system call
793
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800794config IPC_NS
795 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700796 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700797 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800798 help
799 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700800 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800801
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800802config USER_NS
803 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700804 depends on EXPERIMENTAL
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700805 default y
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800806 help
807 This allows containers, i.e. vservers, to use user namespaces
808 to provide different user info for different servers.
809 If unsure, say N.
810
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800811config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700812 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700813 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800814 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300815 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100816 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800817 pid namespaces. This is a building block of containers.
818
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800819config NET_NS
820 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700821 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700822 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800823 help
824 Allow user space to create what appear to be multiple instances
825 of the network stack.
826
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700827endif # NAMESPACES
828
Mike Galbraith5091faa2010-11-30 14:18:03 +0100829config SCHED_AUTOGROUP
830 bool "Automatic process group scheduling"
831 select EVENTFD
832 select CGROUPS
833 select CGROUP_SCHED
834 select FAIR_GROUP_SCHED
835 help
836 This option optimizes the scheduler for common desktop workloads by
837 automatically creating and populating task groups. This separation
838 of workloads isolates aggressive CPU burners (like build jobs) from
839 desktop applications. Task group autogeneration is currently based
840 upon task session.
841
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700842config MM_OWNER
843 bool
844
845config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100846 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700847 depends on SYSFS
848 default n
849 help
850 This option adds code that switches the layout of the "block" class
851 devices, to not show up in /sys/class/block/, but only in
852 /sys/block/.
853
854 This switch is only active when the sysfs.deprecated=1 boot option is
855 passed or the SYSFS_DEPRECATED_V2 option is set.
856
857 This option allows new kernels to run on old distributions and tools,
858 which might get confused by /sys/class/block/. Since 2007/2008 all
859 major distributions and tools handle this just fine.
860
861 Recent distributions and userspace tools after 2009/2010 depend on
862 the existence of /sys/class/block/, and will not work with this
863 option enabled.
864
865 Only if you are using a new kernel on an old distribution, you might
866 need to say Y here.
867
868config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +0100869 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -0700870 default n
871 depends on SYSFS
872 depends on SYSFS_DEPRECATED
873 help
874 Enable deprecated sysfs by default.
875
876 See the CONFIG_SYSFS_DEPRECATED option for more details about this
877 option.
878
879 Only if you are using a new kernel on an old distribution, you might
880 need to say Y here. Even then, odds are you would not need it
881 enabled, you can always pass the boot option if absolutely necessary.
882
883config RELAY
884 bool "Kernel->user space relay support (formerly relayfs)"
885 help
886 This option enables support for relay interface support in
887 certain file systems (such as debugfs).
888 It is designed to provide an efficient mechanism for tools and
889 facilities to relay large amounts of data from kernel space to
890 user space.
891
892 If unsure, say N.
893
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800894config BLK_DEV_INITRD
895 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
896 depends on BROKEN || !FRV
897 help
898 The initial RAM filesystem is a ramfs which is loaded by the
899 boot loader (loadlin or lilo) and that is mounted as root
900 before the normal boot procedure. It is typically used to
901 load modules needed to mount the "real" root file system,
902 etc. See <file:Documentation/initrd.txt> for details.
903
904 If RAM disk support (BLK_DEV_RAM) is also included, this
905 also enables initial RAM disk (initrd) support and adds
906 15 Kbytes (more on some other architectures) to the kernel size.
907
908 If unsure say Y.
909
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800910if BLK_DEV_INITRD
911
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200912source "usr/Kconfig"
913
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800914endif
915
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800916config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200917 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800918 help
919 Enabling this option will pass "-Os" instead of "-O2" to gcc
920 resulting in a smaller kernel.
921
jkacur775a7222008-07-16 00:31:16 +0200922 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800923
Randy Dunlap08470622006-09-30 23:28:13 -0700924config SYSCTL
925 bool
926
Randy Dunlapb943c462009-03-10 12:55:46 -0700927config ANON_INODES
928 bool
929
David Rientjes6a108a12011-01-20 14:44:16 -0800930menuconfig EXPERT
931 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -0700932 # Unhide debug options, to make the on-by-default options visible
933 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 help
935 This option allows certain base kernel options and settings
936 to be disabled or tweaked. This is for specialized
937 environments which can tolerate a "non-standard" kernel.
938 Only use this if you really know what you are doing.
939
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700940config UID16
David Rientjes6a108a12011-01-20 14:44:16 -0800941 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -0700942 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 -0700943 default y
944 help
945 This enables the legacy 16-bit UID syscall wrappers.
946
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700947config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -0800948 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -0800949 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -0700950 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700951 select SYSCTL
952 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800953 sys_sysctl uses binary paths that have been found challenging
954 to properly maintain and use. The interface in /proc/sys
955 using paths with ascii names is now the primary path to this
956 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700957
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800958 Almost nothing using the binary sysctl interface so if you are
959 trying to save some space it is probably safe to disable this,
960 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700961
WANG Congc736de62011-11-02 13:39:25 -0700962 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700963
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -0800965 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 default y
967 help
968 Say Y here to let the kernel print out symbolic crash information and
969 symbolic stack backtraces. This increases the size of the kernel
970 somewhat, as all symbols have to be loaded into the kernel image.
971
972config KALLSYMS_ALL
973 bool "Include all symbols in kallsyms"
974 depends on DEBUG_KERNEL && KALLSYMS
975 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300976 Normally kallsyms only contains the symbols of functions for nicer
977 OOPS messages and backtraces (i.e., symbols from the text and inittext
978 sections). This is sufficient for most cases. And only in very rare
979 cases (e.g., when a debugger is used) all symbols are required (e.g.,
980 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300982 This option makes sure that all symbols are loaded into the kernel
983 image (i.e., symbols from all sections) in cost of increased kernel
984 size (depending on the kernel configuration, it may be 300KiB or
985 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +0300987 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -0700988
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800989config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -0800990 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800991 default y
992 help
993 This option is provided for the case where no hotplug or uevent
994 capabilities is wanted by the kernel. You should only consider
995 disabling this option for embedded systems that do not use modules, a
996 dynamic /dev tree, or dynamic device discovery. Just say Y.
997
Matt Mackalld59745c2005-05-01 08:59:02 -0700998config PRINTK
999 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001000 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001001 help
1002 This option enables normal printk support. Removing it
1003 eliminates most of the message strings from the kernel image
1004 and makes the kernel more or less silent. As this makes it
1005 very difficult to diagnose system problems, saying N here is
1006 strongly discouraged.
1007
Matt Mackallc8538a72005-05-01 08:59:01 -07001008config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001009 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001010 default y
1011 help
1012 Disabling this option eliminates support for BUG and WARN, reducing
1013 the size of your kernel image and potentially quietly ignoring
1014 numerous fatal conditions. You should only consider disabling this
1015 option for embedded systems with no facilities for reporting errors.
1016 Just say Y.
1017
Matt Mackall708e9a72006-01-08 01:05:25 -08001018config ELF_CORE
1019 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001020 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001021 help
1022 Enable support for generating core dumps. Disabling saves about 4k.
1023
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001024
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001025config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001026 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001027 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001028 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001029 default y
1030 help
1031 This option allows to disable the internal PC-Speaker
1032 support, saving some memory.
1033
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001034config HAVE_PCSPKR_PLATFORM
1035 bool
1036
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037config BASE_FULL
1038 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001039 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 help
1041 Disabling this option reduces the size of miscellaneous core
1042 kernel data structures. This saves memory on small machines,
1043 but may reduce performance.
1044
1045config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001046 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -07001048 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 help
1050 Disabling this option will cause the kernel to be built without
1051 support for "fast userspace mutexes". The resulting kernel may not
1052 run glibc-based applications correctly.
1053
1054config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001055 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001057 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 help
1059 Disabling this option will cause the kernel to be built without
1060 support for epoll family of system calls.
1061
Davide Libenzifba2afa2007-05-10 22:23:13 -07001062config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001063 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001064 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001065 default y
1066 help
1067 Enable the signalfd() system call that allows to receive signals
1068 on a file descriptor.
1069
1070 If unsure, say Y.
1071
Davide Libenzib215e282007-05-10 22:23:16 -07001072config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001073 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001074 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001075 default y
1076 help
1077 Enable the timerfd() system call that allows to receive timer
1078 events on a file descriptor.
1079
1080 If unsure, say Y.
1081
Davide Libenzie1ad7462007-05-10 22:23:19 -07001082config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001083 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001084 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001085 default y
1086 help
1087 Enable the eventfd() system call that allows to receive both
1088 kernel notification (ie. KAIO) or userspace notifications.
1089
1090 If unsure, say Y.
1091
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001093 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 default y
1095 depends on MMU
1096 help
1097 The shmem is an internal filesystem used to manage shared memory.
1098 It is backed by swap and manages resource limits. It is also exported
1099 to userspace as tmpfs if TMPFS is enabled. Disabling this
1100 option replaces shmem and tmpfs with the much simpler ramfs code,
1101 which may be appropriate on small systems without swap.
1102
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001103config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001104 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001105 default y
1106 help
1107 This option enables POSIX asynchronous I/O which may by used
1108 by some high performance threaded applications. Disabling
1109 this option saves about 7k.
1110
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001111config EMBEDDED
1112 bool "Embedded system"
1113 select EXPERT
1114 help
1115 This option should be enabled if compiling the kernel for
1116 an embedded system so certain expert options are available
1117 for configuration.
1118
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001119config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001120 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001121 help
1122 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001123
Peter Zijlstra906010b2009-09-21 16:08:49 +02001124config PERF_USE_VMALLOC
1125 bool
1126 help
1127 See tools/perf/design.txt for details
1128
Ingo Molnar57c0c152009-09-21 12:20:38 +02001129menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001130
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001131config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001132 bool "Kernel performance events and counters"
1133 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001134 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001135 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001136 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001137 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001138 Enable kernel support for various performance events provided
1139 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001140
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001141 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001142 use of generic tracepoints.
1143
1144 Most modern CPUs support performance events via performance
1145 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001146 types of hw events: such as instructions executed, cachemisses
1147 suffered, or branches mis-predicted - without slowing down the
1148 kernel or applications. These registers can also trigger interrupts
1149 when a threshold number of events have passed - and can thus be
1150 used to profile the code that runs on that CPU.
1151
Ingo Molnar57c0c152009-09-21 12:20:38 +02001152 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001153 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001154 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001155 provides per task and per CPU counters, and it provides event
1156 capabilities on top of those.
1157
1158 Say Y if unsure.
1159
Ingo Molnar57c0c152009-09-21 12:20:38 +02001160config PERF_COUNTERS
1161 bool "Kernel performance counters (old config option)"
1162 depends on HAVE_PERF_EVENTS
1163 help
1164 This config has been obsoleted by the PERF_EVENTS
1165 config option - please see that one for details.
1166
1167 It has no effect on the kernel whether you enable
1168 it or not, it is a compatibility placeholder.
1169
1170 Say N if unsure.
1171
Peter Zijlstra906010b2009-09-21 16:08:49 +02001172config DEBUG_PERF_USE_VMALLOC
1173 default n
1174 bool "Debug: use vmalloc to back perf mmap() buffers"
1175 depends on PERF_EVENTS && DEBUG_KERNEL
1176 select PERF_USE_VMALLOC
1177 help
1178 Use vmalloc memory to back perf mmap() buffers.
1179
1180 Mostly useful for debugging the vmalloc code on platforms
1181 that don't require it.
1182
1183 Say N if unsure.
1184
Thomas Gleixner0793a612008-12-04 20:12:29 +01001185endmenu
1186
Christoph Lameterf8891e52006-06-30 01:55:45 -07001187config VM_EVENT_COUNTERS
1188 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001189 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001190 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001191 VM event counters are needed for event counts to be shown.
1192 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001193 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001194 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001195
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001196config PCI_QUIRKS
1197 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001198 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001199 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001200 help
1201 This enables workarounds for various PCI chipset
1202 bugs/quirks. Disable this only if your target machine is
1203 unaffected by PCI quirks.
1204
Christoph Lameter41ecc552007-05-09 02:32:44 -07001205config SLUB_DEBUG
1206 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001207 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001208 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001209 help
1210 SLUB has extensive debug support features. Disabling these can
1211 result in significant savings in code size. This also disables
1212 SLUB sysfs support. /sys/slab will not exist and there will be
1213 no support for cache validation etc.
1214
Randy Dunlapb943c462009-03-10 12:55:46 -07001215config COMPAT_BRK
1216 bool "Disable heap randomization"
1217 default y
1218 help
1219 Randomizing heap placement makes heap exploits harder, but it
1220 also breaks ancient binaries (including anything libc5 based).
1221 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001222 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001223 /proc/sys/kernel/randomize_va_space to 2.
1224
1225 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1226
Christoph Lameter81819f02007-05-06 14:49:36 -07001227choice
1228 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001229 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001230 help
1231 This option allows to select a slab allocator.
1232
1233config SLAB
1234 bool "SLAB"
1235 help
1236 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001237 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001238 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001239
1240config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001241 bool "SLUB (Unqueued Allocator)"
1242 help
1243 SLUB is a slab allocator that minimizes cache line usage
1244 instead of managing queues of cached objects (SLAB approach).
1245 Per cpu caching is realized using slabs of objects instead
1246 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001247 and has enhanced diagnostics. SLUB is the default choice for
1248 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001249
1250config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001251 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001252 bool "SLOB (Simple Allocator)"
1253 help
Matt Mackall37291452008-02-04 22:29:38 -08001254 SLOB replaces the stock allocator with a drastically simpler
1255 allocator. SLOB is generally more space efficient but
1256 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001257
1258endchoice
1259
Jie Zhangea637632009-12-14 18:00:02 -08001260config MMAP_ALLOW_UNINITIALIZED
1261 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001262 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001263 default n
1264 help
1265 Normally, and according to the Linux spec, anonymous memory obtained
1266 from mmap() has it's contents cleared before it is passed to
1267 userspace. Enabling this config option allows you to request that
1268 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1269 providing a huge performance boost. If this option is not enabled,
1270 then the flag will be ignored.
1271
1272 This is taken advantage of by uClibc's malloc(), and also by
1273 ELF-FDPIC binfmt's brk and stack allocator.
1274
1275 Because of the obvious security issues, this option should only be
1276 enabled on embedded devices where you control what is run in
1277 userspace. Since that isn't generally a problem on no-MMU systems,
1278 it is normally safe to say Y here.
1279
1280 See Documentation/nommu-mmap.txt for more information.
1281
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001282config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001283 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001284 help
1285 Say Y here to enable the extended profiling support mechanisms used
1286 by profilers such as OProfile.
1287
Ingo Molnar5f87f112008-07-23 14:15:22 +02001288#
1289# Place an empty function call at each tracepoint site. Can be
1290# dynamically changed for a probe function.
1291#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001292config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001293 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001294
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001295source "arch/Kconfig"
1296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297endmenu # General setup
1298
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001299config HAVE_GENERIC_DMA_COHERENT
1300 bool
1301 default n
1302
Linus Torvalds158a9622008-01-02 13:04:48 -08001303config SLABINFO
1304 bool
1305 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001306 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001307 default y
1308
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001309config RT_MUTEXES
1310 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001311
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312config BASE_SMALL
1313 int
1314 default 0 if BASE_FULL
1315 default 1 if !BASE_FULL
1316
Jan Engelhardt66da5732007-07-15 23:39:29 -07001317menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 bool "Enable loadable module support"
1319 help
1320 Kernel modules are small pieces of compiled code which can
1321 be inserted in the running kernel, rather than being
1322 permanently built into the kernel. You use the "modprobe"
1323 tool to add (and sometimes remove) them. If you say Y here,
1324 many parts of the kernel can be built as modules (by
1325 answering M instead of Y where indicated): this is most
1326 useful for infrequently used options which are not required
1327 for booting. For more information, see the man pages for
1328 modprobe, lsmod, modinfo, insmod and rmmod.
1329
1330 If you say Y here, you will need to run "make
1331 modules_install" to put the modules under /lib/modules/
1332 where modprobe can find them (you may need to be root to do
1333 this).
1334
1335 If unsure, say Y.
1336
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001337if MODULES
1338
Linus Torvalds826e4502008-05-04 17:04:16 -07001339config MODULE_FORCE_LOAD
1340 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001341 default n
1342 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001343 Allow loading of modules without version information (ie. modprobe
1344 --force). Forced module loading sets the 'F' (forced) taint flag and
1345 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001346
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347config MODULE_UNLOAD
1348 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 help
1350 Without this option you will not be able to unload any
1351 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001352 anyway), which makes your kernel smaller, faster
1353 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354
1355config MODULE_FORCE_UNLOAD
1356 bool "Forced module unloading"
1357 depends on MODULE_UNLOAD && EXPERIMENTAL
1358 help
1359 This option allows you to force a module to unload, even if the
1360 kernel believes it is unsafe: the kernel will remove the module
1361 without waiting for anyone to stop using it (using the -f option to
1362 rmmod). This is mainly for kernel developers and desperate users.
1363 If unsure, say N.
1364
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001366 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 help
1368 Usually, you have to use modules compiled with your kernel.
1369 Saying Y here makes it sometimes possible to use modules
1370 compiled for different kernels, by adding enough information
1371 to the modules to (hopefully) spot any changes which would
1372 make them incompatible with the kernel you are running. If
1373 unsure, say N.
1374
1375config MODULE_SRCVERSION_ALL
1376 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 help
1378 Modules which contain a MODULE_VERSION get an extra "srcversion"
1379 field inserted into their modinfo section, which contains a
1380 sum of the source files which made it. This helps maintainers
1381 see exactly which source was used to build a module (since
1382 others sometimes change the module source without updating
1383 the version). With this option, such a "srcversion" field
1384 will be created for all modules. If unsure, say N.
1385
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001386endif # MODULES
1387
Rusty Russell98a79d62008-12-13 21:19:41 +10301388config INIT_ALL_POSSIBLE
1389 bool
1390 help
1391 Back when each arch used to define their own cpu_online_map and
1392 cpu_possible_map, some of them chose to initialize cpu_possible_map
1393 with all 1s, and others with all 0s. When they were centralised,
1394 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001395 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301396
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397config STOP_MACHINE
1398 bool
1399 default y
1400 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1401 help
1402 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001403
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001404source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001405
1406config PREEMPT_NOTIFIERS
1407 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001408
Steffen Klassert16295be2010-01-06 19:47:10 +11001409config PADATA
1410 depends on SMP
1411 bool
1412
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001413source "kernel/Kconfig.locks"