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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' Giarrussob2670ea2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
22 default y
23
Al Boldiff0cfc62007-07-31 00:39:23 -070024menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26config EXPERIMENTAL
27 bool "Prompt for development and/or incomplete code/drivers"
28 ---help---
29 Some of the various things that Linux supports (such as network
30 drivers, file systems, network protocols, etc.) can be in a state
31 of development where the functionality, stability, or the level of
32 testing is not yet high enough for general use. This is usually
33 known as the "alpha-test" phase among developers. If a feature is
34 currently in alpha-test, then the developers usually discourage
35 uninformed widespread use of this feature by the general public to
36 avoid "Why doesn't this work?" type mail messages. However, active
37 testing and use of these systems is welcomed. Just be aware that it
38 may not meet the normal level of reliability or it may fail to work
39 in some special cases. Detailed bug reports from people familiar
40 with the kernel internals are usually welcomed by the developers
41 (before submitting bug reports, please read the documents
42 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
43 <file:Documentation/BUG-HUNTING>, and
44 <file:Documentation/oops-tracing.txt> in the kernel source).
45
46 This option will also make obsoleted drivers available. These are
47 drivers that have been replaced by something else, and/or are
48 scheduled to be removed in a future kernel release.
49
50 Unless you intend to help test and develop a feature or driver that
51 falls into this category, or you have a situation that requires
52 using these features, you should probably say N here, which will
53 cause the configurator to present you with fewer choices. If
54 you say Y here, you will be offered the choice of using features or
55 drivers that are currently considered to be in the alpha-test phase.
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057config BROKEN
58 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60config BROKEN_ON_SMP
61 bool
62 depends on BROKEN || !SMP
63 default y
64
65config LOCK_KERNEL
66 bool
67 depends on SMP || PREEMPT
68 default y
69
70config INIT_ENV_ARG_LIMIT
71 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070072 default 32 if !UML
73 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080075 Maximum of each of the number of arguments and environment
76 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Roland McGrath84336462009-12-21 16:24:06 -080079config CROSS_COMPILE
80 string "Cross-compiler tool prefix"
81 help
82 Same as running 'make CROSS_COMPILE=prefix-' but stored for
83 default make runs in this kernel build directory. You don't
84 need to set this unless you want the configured kernel build
85 directory to select the cross-compiler automatically.
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087config LOCALVERSION
88 string "Local version - append to kernel release"
89 help
90 Append an extra string to the end of your kernel version.
91 This will show up when you type uname, for example.
92 The string you set here will be appended after the contents of
93 any files with a filename matching localversion* in your
94 object and source tree, in that order. Your total string can
95 be a maximum of 64 characters.
96
Ryan Andersonaaebf432005-07-31 04:57:49 -040097config LOCALVERSION_AUTO
98 bool "Automatically append version information to the version string"
99 default y
100 help
101 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200102 release tree by looking for git tags that belong to the current
103 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400104
105 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400107 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200108 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400109
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 (The actual string used here is the first eight characters produced
111 by running the command:
112
113 $ git rev-parse --verify HEAD
114
115 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400116
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800117config HAVE_KERNEL_GZIP
118 bool
119
120config HAVE_KERNEL_BZIP2
121 bool
122
123config HAVE_KERNEL_LZMA
124 bool
125
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800126config HAVE_KERNEL_LZO
127 bool
128
Alain Knaff30d65db2009-01-04 22:46:17 +0100129choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800130 prompt "Kernel compression mode"
131 default KERNEL_GZIP
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800132 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800133 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100134 The linux kernel is a kind of self-extracting executable.
135 Several compression algorithms are available, which differ
136 in efficiency, compression and decompression speed.
137 Compression speed is only relevant when building a kernel.
138 Decompression speed is relevant at each boot.
139
140 If you have any problems with bzip2 or lzma compressed
141 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
142 version of this functionality (bzip2 only), for 2.4, was
143 supplied by Christian Ludwig)
144
145 High compression options are mostly useful for users, who
146 are low on disk space (embedded systems), but for whom ram
147 size matters less.
148
149 If in doubt, select 'gzip'
150
151config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800152 bool "Gzip"
153 depends on HAVE_KERNEL_GZIP
154 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800155 The old and tried gzip compression. It provides a good balance
156 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100157
158config KERNEL_BZIP2
159 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800160 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100161 help
162 Its compression ratio and speed is intermediate.
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800163 Decompression speed is slowest among the three. The kernel
164 size is about 10% smaller with bzip2, in comparison to gzip.
165 Bzip2 uses a large amount of memory. For modern kernels you
166 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100167
168config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800169 bool "LZMA"
170 depends on HAVE_KERNEL_LZMA
171 help
172 The most recent compression algorithm.
173 Its ratio is best, decompression speed is between the other
174 two. Compression is slowest. The kernel size is about 33%
175 smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100176
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800177config KERNEL_LZO
178 bool "LZO"
179 depends on HAVE_KERNEL_LZO
180 help
181 Its compression ratio is the poorest among the 4. The kernel
182 size is about about 10% bigger than gzip; however its speed
183 (both compression and decompression) is the fastest.
184
Alain Knaff30d65db2009-01-04 22:46:17 +0100185endchoice
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187config SWAP
188 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200189 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 default y
191 help
192 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100193 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 used to provide more virtual memory than the actual RAM present
195 in your computer. If unsure say Y.
196
197config SYSVIPC
198 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 ---help---
200 Inter Process Communication is a suite of library functions and
201 system calls which let processes (running programs) synchronize and
202 exchange information. It is generally considered to be a good thing,
203 and some programs won't run unless you say Y here. In particular, if
204 you want to run the DOS emulator dosemu under Linux (read the
205 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
206 you'll need to say Y here.
207
208 You can find documentation about IPC with "info ipc" and also in
209 section 6.4 of the Linux Programmer's Guide, available from
210 <http://www.tldp.org/guides.html>.
211
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800212config SYSVIPC_SYSCTL
213 bool
214 depends on SYSVIPC
215 depends on SYSCTL
216 default y
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218config POSIX_MQUEUE
219 bool "POSIX Message Queues"
220 depends on NET && EXPERIMENTAL
221 ---help---
222 POSIX variant of message queues is a part of IPC. In POSIX message
223 queues every message has a priority which decides about succession
224 of receiving it by a process. If you want to compile and run
225 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200226 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 POSIX message queues are visible as a filesystem called 'mqueue'
229 and can be mounted somewhere if you want to do filesystem
230 operations on message queues.
231
232 If unsure, say Y.
233
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700234config POSIX_MQUEUE_SYSCTL
235 bool
236 depends on POSIX_MQUEUE
237 depends on SYSCTL
238 default y
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240config BSD_PROCESS_ACCT
241 bool "BSD Process Accounting"
242 help
243 If you say Y here, a user level program will be able to instruct the
244 kernel (via a special system call) to write process accounting
245 information to a file: whenever a process exits, information about
246 that process will be appended to the file by the kernel. The
247 information includes things such as creation time, owning user,
248 command name, memory usage, controlling terminal etc. (the complete
249 list is in the struct acct in <file:include/linux/acct.h>). It is
250 up to the user level program to do useful things with this
251 information. This is generally a good idea, so say Y.
252
253config BSD_PROCESS_ACCT_V3
254 bool "BSD Process Accounting version 3 file format"
255 depends on BSD_PROCESS_ACCT
256 default n
257 help
258 If you say Y here, the process accounting information is written
259 in a new file format that also logs the process IDs of each
260 process and it's parent. Note that this file format is incompatible
261 with previous v0/v1/v2 file formats, so you will need updated tools
262 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300263 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Shailabh Nagarc7572492006-07-14 00:24:40 -0700265config TASKSTATS
266 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
267 depends on NET
268 default n
269 help
270 Export selected statistics for tasks/processes through the
271 generic netlink interface. Unlike BSD process accounting, the
272 statistics are available during the lifetime of tasks/processes as
273 responses to commands. Like BSD accounting, they are sent to user
274 space on task exit.
275
276 Say N if unsure.
277
Shailabh Nagarca74e922006-07-14 00:24:36 -0700278config TASK_DELAY_ACCT
279 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700280 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700281 help
282 Collect information on time spent by a task waiting for system
283 resources like cpu, synchronous block I/O completion and swapping
284 in pages. Such statistics can help in setting a task's priorities
285 relative to other tasks for cpu, io, rss limits etc.
286
287 Say N if unsure.
288
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800289config TASK_XACCT
290 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
291 depends on TASKSTATS
292 help
293 Collect extended task accounting data and send the data
294 to userland for processing over the taskstats interface.
295
296 Say N if unsure.
297
298config TASK_IO_ACCOUNTING
299 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
300 depends on TASK_XACCT
301 help
302 Collect information on the number of bytes of storage I/O which this
303 task has caused.
304
305 Say N if unsure.
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307config AUDIT
308 bool "Auditing support"
Chris Wright804a6a42005-05-11 10:52:45 +0100309 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 help
311 Enable auditing infrastructure that can be used with another
312 kernel subsystem, such as SELinux (which requires this for
313 logging of avc messages output). Does not do system-call
314 auditing without CONFIG_AUDITSYSCALL.
315
316config AUDITSYSCALL
317 bool "Enable system-call auditing support"
Kumar Gala022382a2009-10-16 07:21:37 +0000318 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 default y if SECURITY_SELINUX
320 help
321 Enable low-overhead system-call auditing infrastructure that
322 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500323 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Eric Paris939a67f2009-12-17 20:12:06 -0500325config AUDIT_WATCH
326 def_bool y
327 depends on AUDITSYSCALL
328 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Al Viro74c3cbe2007-07-22 08:04:18 -0400330config AUDIT_TREE
331 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400332 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500333 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400334
Mike Travisc903ff82009-01-15 12:28:29 -0800335menu "RCU Subsystem"
336
337choice
338 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700339 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800340
Mike Travisc903ff82009-01-15 12:28:29 -0800341config TREE_RCU
342 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700343 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800344 help
345 This option selects the RCU implementation that is
346 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700347 thousands of CPUs. It also scales down nicely to
348 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800349
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700350config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700351 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700352 depends on PREEMPT
353 help
354 This option selects the RCU implementation that is
355 designed for very large SMP systems with hundreds or
356 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700357 is also required. It also scales down nicely to
358 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700359
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700360config TINY_RCU
361 bool "UP-only small-memory-footprint RCU"
362 depends on !SMP
363 help
364 This option selects the RCU implementation that is
365 designed for UP systems from which real-time response
366 is not required. This option greatly reduces the
367 memory footprint of RCU.
368
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700369config TINY_PREEMPT_RCU
370 bool "Preemptible UP-only small-memory-footprint RCU"
371 depends on !SMP && PREEMPT
372 help
373 This option selects the RCU implementation that is designed
374 for real-time UP systems. This option greatly reduces the
375 memory footprint of RCU.
376
Mike Travisc903ff82009-01-15 12:28:29 -0800377endchoice
378
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700379config PREEMPT_RCU
380 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
381 help
382 This option enables preemptible-RCU code that is common between
383 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
384
Mike Travisc903ff82009-01-15 12:28:29 -0800385config RCU_TRACE
386 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700387 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800388 help
389 This option provides tracing in RCU which presents stats
390 in debugfs for debugging RCU implementation.
391
392 Say Y here if you want to enable RCU tracing
393 Say N if you are unsure.
394
395config RCU_FANOUT
396 int "Tree-based hierarchical RCU fanout value"
397 range 2 64 if 64BIT
398 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700399 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800400 default 64 if 64BIT
401 default 32 if !64BIT
402 help
403 This option controls the fanout of hierarchical implementations
404 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700405 large numbers of CPUs. This value must be at least the fourth
406 root of NR_CPUS, which allows NR_CPUS to be insanely large.
407 The default value of RCU_FANOUT should be used for production
408 systems, but if you are stress-testing the RCU implementation
409 itself, small RCU_FANOUT values allow you to test large-system
410 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800411
412 Select a specific number if testing RCU itself.
413 Take the default if unsure.
414
415config RCU_FANOUT_EXACT
416 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700417 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800418 default n
419 help
420 This option forces use of the exact RCU_FANOUT value specified,
421 regardless of imbalances in the hierarchy. This is useful for
422 testing RCU itself, and might one day be useful on systems with
423 strong NUMA behavior.
424
425 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
426
427 Say N if unsure.
428
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800429config RCU_FAST_NO_HZ
430 bool "Accelerate last non-dyntick-idle CPU's grace periods"
431 depends on TREE_RCU && NO_HZ && SMP
432 default n
433 help
434 This option causes RCU to attempt to accelerate grace periods
435 in order to allow the final CPU to enter dynticks-idle state
436 more quickly. On the other hand, this option increases the
437 overhead of the dynticks-idle checking, particularly on systems
438 with large numbers of CPUs.
439
440 Say Y if energy efficiency is critically important, particularly
441 if you have relatively few CPUs.
442
443 Say N if you are unsure.
444
Mike Travisc903ff82009-01-15 12:28:29 -0800445config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700446 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800447 select DEBUG_FS
448 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700449 This option provides tracing for the TREE_RCU and
450 TREE_PREEMPT_RCU implementations, permitting Makefile to
451 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800452
Mike Travisc903ff82009-01-15 12:28:29 -0800453endmenu # "RCU Subsystem"
454
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700456 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 ---help---
458 This option enables the complete Linux kernel ".config" file
459 contents to be saved in the kernel. It provides documentation
460 of which kernel options are used in a running kernel or in an
461 on-disk kernel. This information can be extracted from the kernel
462 image file with the script scripts/extract-ikconfig and used as
463 input to rebuild the current kernel or to build another kernel.
464 It can also be extracted from a running kernel by reading
465 /proc/config.gz if enabled (below).
466
467config IKCONFIG_PROC
468 bool "Enable access to .config through /proc/config.gz"
469 depends on IKCONFIG && PROC_FS
470 ---help---
471 This option enables access to the kernel configuration file
472 through /proc/config.gz.
473
Alistair John Strachan794543a2007-05-08 00:31:15 -0700474config LOG_BUF_SHIFT
475 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
476 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700477 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700478 help
479 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700480 Examples:
481 17 => 128 KB
482 16 => 64 KB
483 15 => 32 KB
484 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700485 13 => 8 KB
486 12 => 4 KB
487
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800488#
489# Architectures with an unreliable sched_clock() should select this:
490#
491config HAVE_UNSTABLE_SCHED_CLOCK
492 bool
493
Li Zefan23964d22009-01-15 13:50:58 -0800494menuconfig CGROUPS
495 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800496 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700497 help
Li Zefan23964d22009-01-15 13:50:58 -0800498 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800499 use with process control subsystems such as Cpusets, CFS, memory
500 controls or device isolation.
501 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800502 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800503 - Documentation/cgroups/ (features for grouping, isolation
504 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700505
506 Say N if unsure.
507
Li Zefan23964d22009-01-15 13:50:58 -0800508if CGROUPS
509
Paul Menage006cb992007-10-18 23:39:43 -0700510config CGROUP_DEBUG
511 bool "Example debug cgroup subsystem"
512 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700513 default n
Paul Menage006cb992007-10-18 23:39:43 -0700514 help
515 This option enables a simple cgroup subsystem that
516 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800517 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700518
Li Zefan23964d22009-01-15 13:50:58 -0800519 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700520
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700521config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800522 bool "Namespace cgroup subsystem"
523 depends on CGROUPS
524 help
525 Provides a simple namespace cgroup subsystem to
526 provide hierarchical naming of sets of namespaces,
527 for instance virtual servers and checkpoint/restart
528 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700529
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700530config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800531 bool "Freezer cgroup subsystem"
532 depends on CGROUPS
533 help
534 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700535 cgroup.
536
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700537config CGROUP_DEVICE
538 bool "Device controller for cgroups"
539 depends on CGROUPS && EXPERIMENTAL
540 help
541 Provides a cgroup implementing whitelists for devices which
542 a process in the cgroup can mknod or open.
543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544config CPUSETS
545 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700546 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700548 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 allow dynamically partitioning a system into sets of CPUs and
550 Memory Nodes and assigning tasks to run only within those sets.
551 This is primarily useful on large SMP or NUMA systems.
552
553 Say N if unsure.
554
Li Zefan23964d22009-01-15 13:50:58 -0800555config PROC_PID_CPUSET
556 bool "Include legacy /proc/<pid>/cpuset file"
557 depends on CPUSETS
558 default y
559
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100560config CGROUP_CPUACCT
561 bool "Simple CPU accounting cgroup subsystem"
562 depends on CGROUPS
563 help
564 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800565 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100566
Pavel Emelianove552b662008-02-07 00:13:49 -0800567config RESOURCE_COUNTERS
568 bool "Resource counters"
569 help
570 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800571 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800572 depends on CGROUPS
573
Balbir Singh00f0b822008-03-04 14:28:39 -0800574config CGROUP_MEM_RES_CTLR
575 bool "Memory Resource Controller for Control Groups"
576 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700577 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800578 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700579 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100580 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800581
582 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700583 associated with each page of memory in the system. By this,
584 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
585 usage tracking struct at boot. Total amount of this is printed out
586 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800587
588 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700589 sure you need the memory resource controller. Even when you enable
590 this, you can set "cgroup_disable=memory" at your boot option to
591 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800592 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800593
Balbir Singhcf475ad2008-04-29 01:00:16 -0700594 This config option also selects MM_OWNER config option, which
595 could in turn add some fork/exit overhead.
596
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800597config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700598 bool "Memory Resource Controller Swap Extension"
599 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800600 help
601 Add swap management feature to memory resource controller. When you
602 enable this, you can limit mem+swap usage per cgroup. In other words,
603 when you disable this, memory resource controller has no cares to
604 usage of swap...a process can exhaust all of the swap. This extension
605 is useful when you want to avoid exhaustion swap but this itself
606 adds more overheads and consumes memory for remembering information.
607 Especially if you use 32bit system or small memory system, please
608 be careful about enabling this. When memory resource controller
609 is disabled by boot option, this will be automatically disabled and
610 there will be no overhead from this. Even when you set this config=y,
611 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700612 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
613 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800614
Dhaval Giani7c941432010-01-20 13:26:18 +0100615menuconfig CGROUP_SCHED
616 bool "Group CPU scheduler"
617 depends on EXPERIMENTAL && CGROUPS
618 default n
619 help
620 This feature lets CPU scheduler recognize task groups and control CPU
621 bandwidth allocation to such task groups. It uses cgroups to group
622 tasks.
623
624if CGROUP_SCHED
625config FAIR_GROUP_SCHED
626 bool "Group scheduling for SCHED_OTHER"
627 depends on CGROUP_SCHED
628 default CGROUP_SCHED
629
630config RT_GROUP_SCHED
631 bool "Group scheduling for SCHED_RR/FIFO"
632 depends on EXPERIMENTAL
633 depends on CGROUP_SCHED
634 default n
635 help
636 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800637 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100638 schedule realtime tasks for non-root users until you allocate
639 realtime bandwidth for them.
640 See Documentation/scheduler/sched-rt-group.txt for more information.
641
642endif #CGROUP_SCHED
643
Vivek Goyalafc24d42010-04-26 19:27:56 +0200644config BLK_CGROUP
645 tristate "Block IO controller"
646 depends on CGROUPS && BLOCK
647 default n
648 ---help---
649 Generic block IO controller cgroup interface. This is the common
650 cgroup interface which should be used by various IO controlling
651 policies.
652
653 Currently, CFQ IO scheduler uses it to recognize task groups and
654 control disk bandwidth allocation (proportional time slice allocation)
655 to such task groups.
656
657 This option only enables generic Block IO controller infrastructure.
658 One needs to also enable actual IO controlling logic in CFQ for it
659 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
660
661 See Documentation/cgroups/blkio-controller.txt for more information.
662
663config DEBUG_BLK_CGROUP
664 bool "Enable Block IO controller debugging"
665 depends on BLK_CGROUP
666 default n
667 ---help---
668 Enable some debugging help. Currently it exports additional stat
669 files in a cgroup which can be useful for debugging.
670
Li Zefan23964d22009-01-15 13:50:58 -0800671endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800672
Li Zefan23964d22009-01-15 13:50:58 -0800673config MM_OWNER
674 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800675
Kay Sievers88a22c92006-09-14 11:23:28 +0200676config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100677 bool
678
679config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100680 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800681 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200682 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100683 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200684 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100685 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200686 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200687
Kay Sieversfce3e802008-11-01 14:03:00 +0100688 The current sysfs layout features a unified device tree at
689 /sys/devices/, which is able to express a hierarchy between
690 class devices. If the deprecated option is set to Y, the
691 unified device tree is split into a bus device tree at
692 /sys/devices/ and several individual class device trees at
693 /sys/class/. The class and bus devices will be connected by
694 "<subsystem>:<name>" and the "device" links. The "block"
695 class devices, will not show up in /sys/class/block/. Some
696 subsystems will suppress the creation of some devices which
697 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200698
Kay Sieversfce3e802008-11-01 14:03:00 +0100699 This option is not a pure compatibility option that can
700 be safely enabled on newer distributions. It will change the
701 layout of sysfs to the non-extensible deprecated version,
702 and disable some features, which can not be exported without
703 confusing older userspace tools. Since 2007/2008 all major
704 distributions do not enable this option, and ship no tools which
705 depend on the deprecated layout or this option.
706
707 If you are using a new kernel on an older distribution, or use
708 older userspace tools, you might need to say Y here. Do not say Y,
709 if the original kernel, that came with your distribution, has
710 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200711
Jens Axboeb86ff982006-03-23 19:56:55 +0100712config RELAY
713 bool "Kernel->user space relay support (formerly relayfs)"
714 help
715 This option enables support for relay interface support in
716 certain file systems (such as debugfs).
717 It is designed to provide an efficient mechanism for tools and
718 facilities to relay large amounts of data from kernel space to
719 user space.
720
721 If unsure, say N.
722
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800723config NAMESPACES
724 bool "Namespaces support" if EMBEDDED
725 default !EMBEDDED
726 help
727 Provides the way to make tasks work with different objects using
728 the same id. For example same IPC id may refer to different objects
729 or same user id or pid may refer to different tasks when used in
730 different namespaces.
731
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800732config UTS_NS
733 bool "UTS namespace"
734 depends on NAMESPACES
735 help
736 In this namespace tasks see different info provided with the
737 uname() system call
738
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800739config IPC_NS
740 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700741 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800742 help
743 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700744 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800745
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800746config USER_NS
747 bool "User namespace (EXPERIMENTAL)"
748 depends on NAMESPACES && EXPERIMENTAL
749 help
750 This allows containers, i.e. vservers, to use user namespaces
751 to provide different user info for different servers.
752 If unsure, say N.
753
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800754config PID_NS
755 bool "PID Namespaces (EXPERIMENTAL)"
756 default n
757 depends on NAMESPACES && EXPERIMENTAL
758 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300759 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100760 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800761 pid namespaces. This is a building block of containers.
762
763 Unless you want to work with an experimental feature
764 say N here.
765
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800766config NET_NS
767 bool "Network namespace"
768 default n
769 depends on NAMESPACES && EXPERIMENTAL && NET
770 help
771 Allow user space to create what appear to be multiple instances
772 of the network stack.
773
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800774config BLK_DEV_INITRD
775 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
776 depends on BROKEN || !FRV
777 help
778 The initial RAM filesystem is a ramfs which is loaded by the
779 boot loader (loadlin or lilo) and that is mounted as root
780 before the normal boot procedure. It is typically used to
781 load modules needed to mount the "real" root file system,
782 etc. See <file:Documentation/initrd.txt> for details.
783
784 If RAM disk support (BLK_DEV_RAM) is also included, this
785 also enables initial RAM disk (initrd) support and adds
786 15 Kbytes (more on some other architectures) to the kernel size.
787
788 If unsure say Y.
789
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800790if BLK_DEV_INITRD
791
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200792source "usr/Kconfig"
793
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800794endif
795
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800796config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200797 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800798 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800799 help
800 Enabling this option will pass "-Os" instead of "-O2" to gcc
801 resulting in a smaller kernel.
802
jkacur775a7222008-07-16 00:31:16 +0200803 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800804
Randy Dunlap08470622006-09-30 23:28:13 -0700805config SYSCTL
806 bool
807
Randy Dunlapb943c462009-03-10 12:55:46 -0700808config ANON_INODES
809 bool
810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811menuconfig EMBEDDED
812 bool "Configure standard kernel features (for small systems)"
813 help
814 This option allows certain base kernel options and settings
815 to be disabled or tweaked. This is for specialized
816 environments which can tolerate a "non-standard" kernel.
817 Only use this if you really know what you are doing.
818
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700819config UID16
820 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700821 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 -0700822 default y
823 help
824 This enables the legacy 16-bit UID syscall wrappers.
825
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700826config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700827 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800828 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800829 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700830 select SYSCTL
831 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800832 sys_sysctl uses binary paths that have been found challenging
833 to properly maintain and use. The interface in /proc/sys
834 using paths with ascii names is now the primary path to this
835 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700836
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800837 Almost nothing using the binary sysctl interface so if you are
838 trying to save some space it is probably safe to disable this,
839 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700840
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800841 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700842
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100844 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 default y
846 help
847 Say Y here to let the kernel print out symbolic crash information and
848 symbolic stack backtraces. This increases the size of the kernel
849 somewhat, as all symbols have to be loaded into the kernel image.
850
851config KALLSYMS_ALL
852 bool "Include all symbols in kallsyms"
853 depends on DEBUG_KERNEL && KALLSYMS
854 help
855 Normally kallsyms only contains the symbols of functions, for nicer
856 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200857 symbols too: say Y here to include all symbols, if you need them
858 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
860 Say N.
861
862config KALLSYMS_EXTRA_PASS
863 bool "Do an extra kallsyms pass"
864 depends on KALLSYMS
865 help
866 If kallsyms is not working correctly, the build will fail with
867 inconsistent kallsyms data. If that occurs, log a bug report and
868 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
869 Always say N here unless you find a bug in kallsyms, which must be
870 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
871 you wait for kallsyms to be fixed.
872
Matt Mackalld59745c2005-05-01 08:59:02 -0700873
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800874config HOTPLUG
875 bool "Support for hot-pluggable devices" if EMBEDDED
876 default y
877 help
878 This option is provided for the case where no hotplug or uevent
879 capabilities is wanted by the kernel. You should only consider
880 disabling this option for embedded systems that do not use modules, a
881 dynamic /dev tree, or dynamic device discovery. Just say Y.
882
Matt Mackalld59745c2005-05-01 08:59:02 -0700883config PRINTK
884 default y
885 bool "Enable support for printk" if EMBEDDED
886 help
887 This option enables normal printk support. Removing it
888 eliminates most of the message strings from the kernel image
889 and makes the kernel more or less silent. As this makes it
890 very difficult to diagnose system problems, saying N here is
891 strongly discouraged.
892
Matt Mackallc8538a72005-05-01 08:59:01 -0700893config BUG
894 bool "BUG() support" if EMBEDDED
895 default y
896 help
897 Disabling this option eliminates support for BUG and WARN, reducing
898 the size of your kernel image and potentially quietly ignoring
899 numerous fatal conditions. You should only consider disabling this
900 option for embedded systems with no facilities for reporting errors.
901 Just say Y.
902
Matt Mackall708e9a72006-01-08 01:05:25 -0800903config ELF_CORE
904 default y
905 bool "Enable ELF core dumps" if EMBEDDED
906 help
907 Enable support for generating core dumps. Disabling saves about 4k.
908
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200909config PCSPKR_PLATFORM
910 bool "Enable PC-Speaker support" if EMBEDDED
911 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
912 default y
913 help
914 This option allows to disable the internal PC-Speaker
915 support, saving some memory.
916
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917config BASE_FULL
918 default y
919 bool "Enable full-sized data structures for core" if EMBEDDED
920 help
921 Disabling this option reduces the size of miscellaneous core
922 kernel data structures. This saves memory on small machines,
923 but may reduce performance.
924
925config FUTEX
926 bool "Enable futex support" if EMBEDDED
927 default y
Ingo Molnar23f78d42006-06-27 02:54:53 -0700928 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 help
930 Disabling this option will cause the kernel to be built without
931 support for "fast userspace mutexes". The resulting kernel may not
932 run glibc-based applications correctly.
933
934config EPOLL
935 bool "Enable eventpoll support" if EMBEDDED
936 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700937 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 help
939 Disabling this option will cause the kernel to be built without
940 support for epoll family of system calls.
941
Davide Libenzifba2afa2007-05-10 22:23:13 -0700942config SIGNALFD
943 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700944 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700945 default y
946 help
947 Enable the signalfd() system call that allows to receive signals
948 on a file descriptor.
949
950 If unsure, say Y.
951
Davide Libenzib215e282007-05-10 22:23:16 -0700952config TIMERFD
953 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700954 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700955 default y
956 help
957 Enable the timerfd() system call that allows to receive timer
958 events on a file descriptor.
959
960 If unsure, say Y.
961
Davide Libenzie1ad7462007-05-10 22:23:19 -0700962config EVENTFD
963 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700964 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700965 default y
966 help
967 Enable the eventfd() system call that allows to receive both
968 kernel notification (ie. KAIO) or userspace notifications.
969
970 If unsure, say Y.
971
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972config SHMEM
973 bool "Use full shmem filesystem" if EMBEDDED
974 default y
975 depends on MMU
976 help
977 The shmem is an internal filesystem used to manage shared memory.
978 It is backed by swap and manages resource limits. It is also exported
979 to userspace as tmpfs if TMPFS is enabled. Disabling this
980 option replaces shmem and tmpfs with the much simpler ramfs code,
981 which may be appropriate on small systems without swap.
982
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700983config AIO
984 bool "Enable AIO support" if EMBEDDED
985 default y
986 help
987 This option enables POSIX asynchronous I/O which may by used
988 by some high performance threaded applications. Disabling
989 this option saves about 7k.
990
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200991config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100992 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400993 help
994 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100995
Peter Zijlstra906010b2009-09-21 16:08:49 +0200996config PERF_USE_VMALLOC
997 bool
998 help
999 See tools/perf/design.txt for details
1000
Ingo Molnar57c0c152009-09-21 12:20:38 +02001001menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001002
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001003config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001004 bool "Kernel performance events and counters"
1005 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001006 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001007 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +01001008 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001009 Enable kernel support for various performance events provided
1010 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001011
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001012 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001013 use of generic tracepoints.
1014
1015 Most modern CPUs support performance events via performance
1016 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001017 types of hw events: such as instructions executed, cachemisses
1018 suffered, or branches mis-predicted - without slowing down the
1019 kernel or applications. These registers can also trigger interrupts
1020 when a threshold number of events have passed - and can thus be
1021 used to profile the code that runs on that CPU.
1022
Ingo Molnar57c0c152009-09-21 12:20:38 +02001023 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001024 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001025 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001026 provides per task and per CPU counters, and it provides event
1027 capabilities on top of those.
1028
1029 Say Y if unsure.
1030
Ingo Molnar57c0c152009-09-21 12:20:38 +02001031config PERF_COUNTERS
1032 bool "Kernel performance counters (old config option)"
1033 depends on HAVE_PERF_EVENTS
1034 help
1035 This config has been obsoleted by the PERF_EVENTS
1036 config option - please see that one for details.
1037
1038 It has no effect on the kernel whether you enable
1039 it or not, it is a compatibility placeholder.
1040
1041 Say N if unsure.
1042
Peter Zijlstra906010b2009-09-21 16:08:49 +02001043config DEBUG_PERF_USE_VMALLOC
1044 default n
1045 bool "Debug: use vmalloc to back perf mmap() buffers"
1046 depends on PERF_EVENTS && DEBUG_KERNEL
1047 select PERF_USE_VMALLOC
1048 help
1049 Use vmalloc memory to back perf mmap() buffers.
1050
1051 Mostly useful for debugging the vmalloc code on platforms
1052 that don't require it.
1053
1054 Say N if unsure.
1055
Thomas Gleixner0793a612008-12-04 20:12:29 +01001056endmenu
1057
Christoph Lameterf8891e52006-06-30 01:55:45 -07001058config VM_EVENT_COUNTERS
1059 default y
1060 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1061 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001062 VM event counters are needed for event counts to be shown.
1063 This option allows the disabling of the VM event counters
1064 on EMBEDDED systems. /proc/vmstat will only show page counts
1065 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001066
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001067config PCI_QUIRKS
1068 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001069 bool "Enable PCI quirk workarounds" if EMBEDDED
1070 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001071 help
1072 This enables workarounds for various PCI chipset
1073 bugs/quirks. Disable this only if your target machine is
1074 unaffected by PCI quirks.
1075
Christoph Lameter41ecc552007-05-09 02:32:44 -07001076config SLUB_DEBUG
1077 default y
1078 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001079 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001080 help
1081 SLUB has extensive debug support features. Disabling these can
1082 result in significant savings in code size. This also disables
1083 SLUB sysfs support. /sys/slab will not exist and there will be
1084 no support for cache validation etc.
1085
Randy Dunlapb943c462009-03-10 12:55:46 -07001086config COMPAT_BRK
1087 bool "Disable heap randomization"
1088 default y
1089 help
1090 Randomizing heap placement makes heap exploits harder, but it
1091 also breaks ancient binaries (including anything libc5 based).
1092 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001093 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001094 /proc/sys/kernel/randomize_va_space to 2.
1095
1096 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1097
Christoph Lameter81819f02007-05-06 14:49:36 -07001098choice
1099 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001100 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001101 help
1102 This option allows to select a slab allocator.
1103
1104config SLAB
1105 bool "SLAB"
1106 help
1107 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001108 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001109 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001110
1111config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001112 bool "SLUB (Unqueued Allocator)"
1113 help
1114 SLUB is a slab allocator that minimizes cache line usage
1115 instead of managing queues of cached objects (SLAB approach).
1116 Per cpu caching is realized using slabs of objects instead
1117 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001118 and has enhanced diagnostics. SLUB is the default choice for
1119 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001120
1121config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001122 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001123 bool "SLOB (Simple Allocator)"
1124 help
Matt Mackall37291452008-02-04 22:29:38 -08001125 SLOB replaces the stock allocator with a drastically simpler
1126 allocator. SLOB is generally more space efficient but
1127 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001128
1129endchoice
1130
Jie Zhangea637632009-12-14 18:00:02 -08001131config MMAP_ALLOW_UNINITIALIZED
1132 bool "Allow mmapped anonymous memory to be uninitialized"
1133 depends on EMBEDDED && !MMU
1134 default n
1135 help
1136 Normally, and according to the Linux spec, anonymous memory obtained
1137 from mmap() has it's contents cleared before it is passed to
1138 userspace. Enabling this config option allows you to request that
1139 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1140 providing a huge performance boost. If this option is not enabled,
1141 then the flag will be ignored.
1142
1143 This is taken advantage of by uClibc's malloc(), and also by
1144 ELF-FDPIC binfmt's brk and stack allocator.
1145
1146 Because of the obvious security issues, this option should only be
1147 enabled on embedded devices where you control what is run in
1148 userspace. Since that isn't generally a problem on no-MMU systems,
1149 it is normally safe to say Y here.
1150
1151 See Documentation/nommu-mmap.txt for more information.
1152
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001153config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001154 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001155 help
1156 Say Y here to enable the extended profiling support mechanisms used
1157 by profilers such as OProfile.
1158
Ingo Molnar5f87f112008-07-23 14:15:22 +02001159#
1160# Place an empty function call at each tracepoint site. Can be
1161# dynamically changed for a probe function.
1162#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001163config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001164 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001165
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001166source "arch/Kconfig"
1167
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168endmenu # General setup
1169
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001170config HAVE_GENERIC_DMA_COHERENT
1171 bool
1172 default n
1173
Linus Torvalds158a9622008-01-02 13:04:48 -08001174config SLABINFO
1175 bool
1176 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001177 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001178 default y
1179
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001180config RT_MUTEXES
1181 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001182
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183config BASE_SMALL
1184 int
1185 default 0 if BASE_FULL
1186 default 1 if !BASE_FULL
1187
Jan Engelhardt66da5732007-07-15 23:39:29 -07001188menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 bool "Enable loadable module support"
1190 help
1191 Kernel modules are small pieces of compiled code which can
1192 be inserted in the running kernel, rather than being
1193 permanently built into the kernel. You use the "modprobe"
1194 tool to add (and sometimes remove) them. If you say Y here,
1195 many parts of the kernel can be built as modules (by
1196 answering M instead of Y where indicated): this is most
1197 useful for infrequently used options which are not required
1198 for booting. For more information, see the man pages for
1199 modprobe, lsmod, modinfo, insmod and rmmod.
1200
1201 If you say Y here, you will need to run "make
1202 modules_install" to put the modules under /lib/modules/
1203 where modprobe can find them (you may need to be root to do
1204 this).
1205
1206 If unsure, say Y.
1207
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001208if MODULES
1209
Linus Torvalds826e4502008-05-04 17:04:16 -07001210config MODULE_FORCE_LOAD
1211 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001212 default n
1213 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001214 Allow loading of modules without version information (ie. modprobe
1215 --force). Forced module loading sets the 'F' (forced) taint flag and
1216 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001217
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218config MODULE_UNLOAD
1219 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 help
1221 Without this option you will not be able to unload any
1222 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001223 anyway), which makes your kernel smaller, faster
1224 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225
1226config MODULE_FORCE_UNLOAD
1227 bool "Forced module unloading"
1228 depends on MODULE_UNLOAD && EXPERIMENTAL
1229 help
1230 This option allows you to force a module to unload, even if the
1231 kernel believes it is unsafe: the kernel will remove the module
1232 without waiting for anyone to stop using it (using the -f option to
1233 rmmod). This is mainly for kernel developers and desperate users.
1234 If unsure, say N.
1235
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001237 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 help
1239 Usually, you have to use modules compiled with your kernel.
1240 Saying Y here makes it sometimes possible to use modules
1241 compiled for different kernels, by adding enough information
1242 to the modules to (hopefully) spot any changes which would
1243 make them incompatible with the kernel you are running. If
1244 unsure, say N.
1245
1246config MODULE_SRCVERSION_ALL
1247 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 help
1249 Modules which contain a MODULE_VERSION get an extra "srcversion"
1250 field inserted into their modinfo section, which contains a
1251 sum of the source files which made it. This helps maintainers
1252 see exactly which source was used to build a module (since
1253 others sometimes change the module source without updating
1254 the version). With this option, such a "srcversion" field
1255 will be created for all modules. If unsure, say N.
1256
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001257endif # MODULES
1258
Rusty Russell98a79d62008-12-13 21:19:41 +10301259config INIT_ALL_POSSIBLE
1260 bool
1261 help
1262 Back when each arch used to define their own cpu_online_map and
1263 cpu_possible_map, some of them chose to initialize cpu_possible_map
1264 with all 1s, and others with all 0s. When they were centralised,
1265 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001266 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301267
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268config STOP_MACHINE
1269 bool
1270 default y
1271 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1272 help
1273 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001274
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001275source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001276
1277config PREEMPT_NOTIFIERS
1278 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001279
Steffen Klassert16295be2010-01-06 19:47:10 +11001280config PADATA
1281 depends on SMP
1282 bool
1283
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001284source "kernel/Kconfig.locks"