blob: 79ac52bef4ce8de657b449a0ac949077362f7a75 [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' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
22 default y
23
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47 drivers that have been replaced by something else, and/or are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 Wright804a6a492005-05-11 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
351 bool "Preemptable tree-based hierarchical RCU"
352 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
Mike Travisc903ff82009-01-15 12:28:29 -0800369endchoice
370
371config RCU_TRACE
372 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700373 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800374 help
375 This option provides tracing in RCU which presents stats
376 in debugfs for debugging RCU implementation.
377
378 Say Y here if you want to enable RCU tracing
379 Say N if you are unsure.
380
381config RCU_FANOUT
382 int "Tree-based hierarchical RCU fanout value"
383 range 2 64 if 64BIT
384 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700385 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800386 default 64 if 64BIT
387 default 32 if !64BIT
388 help
389 This option controls the fanout of hierarchical implementations
390 of RCU, allowing RCU to work efficiently on machines with
391 large numbers of CPUs. This value must be at least the cube
392 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
393 systems and up to 262,144 for 64-bit systems.
394
395 Select a specific number if testing RCU itself.
396 Take the default if unsure.
397
398config RCU_FANOUT_EXACT
399 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700400 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800401 default n
402 help
403 This option forces use of the exact RCU_FANOUT value specified,
404 regardless of imbalances in the hierarchy. This is useful for
405 testing RCU itself, and might one day be useful on systems with
406 strong NUMA behavior.
407
408 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
409
410 Say N if unsure.
411
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800412config RCU_FAST_NO_HZ
413 bool "Accelerate last non-dyntick-idle CPU's grace periods"
414 depends on TREE_RCU && NO_HZ && SMP
415 default n
416 help
417 This option causes RCU to attempt to accelerate grace periods
418 in order to allow the final CPU to enter dynticks-idle state
419 more quickly. On the other hand, this option increases the
420 overhead of the dynticks-idle checking, particularly on systems
421 with large numbers of CPUs.
422
423 Say Y if energy efficiency is critically important, particularly
424 if you have relatively few CPUs.
425
426 Say N if you are unsure.
427
Mike Travisc903ff82009-01-15 12:28:29 -0800428config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700429 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800430 select DEBUG_FS
431 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700432 This option provides tracing for the TREE_RCU and
433 TREE_PREEMPT_RCU implementations, permitting Makefile to
434 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800435
Mike Travisc903ff82009-01-15 12:28:29 -0800436endmenu # "RCU Subsystem"
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700439 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 ---help---
441 This option enables the complete Linux kernel ".config" file
442 contents to be saved in the kernel. It provides documentation
443 of which kernel options are used in a running kernel or in an
444 on-disk kernel. This information can be extracted from the kernel
445 image file with the script scripts/extract-ikconfig and used as
446 input to rebuild the current kernel or to build another kernel.
447 It can also be extracted from a running kernel by reading
448 /proc/config.gz if enabled (below).
449
450config IKCONFIG_PROC
451 bool "Enable access to .config through /proc/config.gz"
452 depends on IKCONFIG && PROC_FS
453 ---help---
454 This option enables access to the kernel configuration file
455 through /proc/config.gz.
456
Alistair John Strachan794543a2007-05-08 00:31:15 -0700457config LOG_BUF_SHIFT
458 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
459 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700460 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700461 help
462 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700463 Examples:
464 17 => 128 KB
465 16 => 64 KB
466 15 => 32 KB
467 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700468 13 => 8 KB
469 12 => 4 KB
470
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800471#
472# Architectures with an unreliable sched_clock() should select this:
473#
474config HAVE_UNSTABLE_SCHED_CLOCK
475 bool
476
Li Zefan23964d22009-01-15 13:50:58 -0800477menuconfig CGROUPS
478 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800479 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700480 help
Li Zefan23964d22009-01-15 13:50:58 -0800481 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800482 use with process control subsystems such as Cpusets, CFS, memory
483 controls or device isolation.
484 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800485 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800486 - Documentation/cgroups/ (features for grouping, isolation
487 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700488
489 Say N if unsure.
490
Li Zefan23964d22009-01-15 13:50:58 -0800491if CGROUPS
492
Paul Menage006cb992007-10-18 23:39:43 -0700493config CGROUP_DEBUG
494 bool "Example debug cgroup subsystem"
495 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700496 default n
Paul Menage006cb992007-10-18 23:39:43 -0700497 help
498 This option enables a simple cgroup subsystem that
499 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800500 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700501
Li Zefan23964d22009-01-15 13:50:58 -0800502 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700503
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700504config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800505 bool "Namespace cgroup subsystem"
506 depends on CGROUPS
507 help
508 Provides a simple namespace cgroup subsystem to
509 provide hierarchical naming of sets of namespaces,
510 for instance virtual servers and checkpoint/restart
511 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700512
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700513config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800514 bool "Freezer cgroup subsystem"
515 depends on CGROUPS
516 help
517 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700518 cgroup.
519
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700520config CGROUP_DEVICE
521 bool "Device controller for cgroups"
522 depends on CGROUPS && EXPERIMENTAL
523 help
524 Provides a cgroup implementing whitelists for devices which
525 a process in the cgroup can mknod or open.
526
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527config CPUSETS
528 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700529 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700531 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 allow dynamically partitioning a system into sets of CPUs and
533 Memory Nodes and assigning tasks to run only within those sets.
534 This is primarily useful on large SMP or NUMA systems.
535
536 Say N if unsure.
537
Li Zefan23964d22009-01-15 13:50:58 -0800538config PROC_PID_CPUSET
539 bool "Include legacy /proc/<pid>/cpuset file"
540 depends on CPUSETS
541 default y
542
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100543config CGROUP_CPUACCT
544 bool "Simple CPU accounting cgroup subsystem"
545 depends on CGROUPS
546 help
547 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800548 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100549
Pavel Emelianove552b662008-02-07 00:13:49 -0800550config RESOURCE_COUNTERS
551 bool "Resource counters"
552 help
553 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800554 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800555 depends on CGROUPS
556
Balbir Singh00f0b822008-03-04 14:28:39 -0800557config CGROUP_MEM_RES_CTLR
558 bool "Memory Resource Controller for Control Groups"
559 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700560 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800561 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700562 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100563 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800564
565 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700566 associated with each page of memory in the system. By this,
567 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
568 usage tracking struct at boot. Total amount of this is printed out
569 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800570
571 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700572 sure you need the memory resource controller. Even when you enable
573 this, you can set "cgroup_disable=memory" at your boot option to
574 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800575 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800576
Balbir Singhcf475ad2008-04-29 01:00:16 -0700577 This config option also selects MM_OWNER config option, which
578 could in turn add some fork/exit overhead.
579
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800580config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700581 bool "Memory Resource Controller Swap Extension"
582 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800583 help
584 Add swap management feature to memory resource controller. When you
585 enable this, you can limit mem+swap usage per cgroup. In other words,
586 when you disable this, memory resource controller has no cares to
587 usage of swap...a process can exhaust all of the swap. This extension
588 is useful when you want to avoid exhaustion swap but this itself
589 adds more overheads and consumes memory for remembering information.
590 Especially if you use 32bit system or small memory system, please
591 be careful about enabling this. When memory resource controller
592 is disabled by boot option, this will be automatically disabled and
593 there will be no overhead from this. Even when you set this config=y,
594 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700595 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
596 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800597
Dhaval Giani7c941432010-01-20 13:26:18 +0100598menuconfig CGROUP_SCHED
599 bool "Group CPU scheduler"
600 depends on EXPERIMENTAL && CGROUPS
601 default n
602 help
603 This feature lets CPU scheduler recognize task groups and control CPU
604 bandwidth allocation to such task groups. It uses cgroups to group
605 tasks.
606
607if CGROUP_SCHED
608config FAIR_GROUP_SCHED
609 bool "Group scheduling for SCHED_OTHER"
610 depends on CGROUP_SCHED
611 default CGROUP_SCHED
612
613config RT_GROUP_SCHED
614 bool "Group scheduling for SCHED_RR/FIFO"
615 depends on EXPERIMENTAL
616 depends on CGROUP_SCHED
617 default n
618 help
619 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800620 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100621 schedule realtime tasks for non-root users until you allocate
622 realtime bandwidth for them.
623 See Documentation/scheduler/sched-rt-group.txt for more information.
624
625endif #CGROUP_SCHED
626
Vivek Goyalafc24d42010-04-26 19:27:56 +0200627config BLK_CGROUP
628 tristate "Block IO controller"
629 depends on CGROUPS && BLOCK
630 default n
631 ---help---
632 Generic block IO controller cgroup interface. This is the common
633 cgroup interface which should be used by various IO controlling
634 policies.
635
636 Currently, CFQ IO scheduler uses it to recognize task groups and
637 control disk bandwidth allocation (proportional time slice allocation)
638 to such task groups.
639
640 This option only enables generic Block IO controller infrastructure.
641 One needs to also enable actual IO controlling logic in CFQ for it
642 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
643
644 See Documentation/cgroups/blkio-controller.txt for more information.
645
646config DEBUG_BLK_CGROUP
647 bool "Enable Block IO controller debugging"
648 depends on BLK_CGROUP
649 default n
650 ---help---
651 Enable some debugging help. Currently it exports additional stat
652 files in a cgroup which can be useful for debugging.
653
Li Zefan23964d22009-01-15 13:50:58 -0800654endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800655
Li Zefan23964d22009-01-15 13:50:58 -0800656config MM_OWNER
657 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800658
Kay Sievers88a22c92006-09-14 11:23:28 +0200659config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100660 bool
661
662config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100663 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800664 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200665 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100666 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200667 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100668 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200669 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200670
Kay Sieversfce3e802008-11-01 14:03:00 +0100671 The current sysfs layout features a unified device tree at
672 /sys/devices/, which is able to express a hierarchy between
673 class devices. If the deprecated option is set to Y, the
674 unified device tree is split into a bus device tree at
675 /sys/devices/ and several individual class device trees at
676 /sys/class/. The class and bus devices will be connected by
677 "<subsystem>:<name>" and the "device" links. The "block"
678 class devices, will not show up in /sys/class/block/. Some
679 subsystems will suppress the creation of some devices which
680 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200681
Kay Sieversfce3e802008-11-01 14:03:00 +0100682 This option is not a pure compatibility option that can
683 be safely enabled on newer distributions. It will change the
684 layout of sysfs to the non-extensible deprecated version,
685 and disable some features, which can not be exported without
686 confusing older userspace tools. Since 2007/2008 all major
687 distributions do not enable this option, and ship no tools which
688 depend on the deprecated layout or this option.
689
690 If you are using a new kernel on an older distribution, or use
691 older userspace tools, you might need to say Y here. Do not say Y,
692 if the original kernel, that came with your distribution, has
693 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200694
Jens Axboeb86ff9812006-03-23 19:56:55 +0100695config RELAY
696 bool "Kernel->user space relay support (formerly relayfs)"
697 help
698 This option enables support for relay interface support in
699 certain file systems (such as debugfs).
700 It is designed to provide an efficient mechanism for tools and
701 facilities to relay large amounts of data from kernel space to
702 user space.
703
704 If unsure, say N.
705
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800706config NAMESPACES
707 bool "Namespaces support" if EMBEDDED
708 default !EMBEDDED
709 help
710 Provides the way to make tasks work with different objects using
711 the same id. For example same IPC id may refer to different objects
712 or same user id or pid may refer to different tasks when used in
713 different namespaces.
714
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800715config UTS_NS
716 bool "UTS namespace"
717 depends on NAMESPACES
718 help
719 In this namespace tasks see different info provided with the
720 uname() system call
721
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800722config IPC_NS
723 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700724 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800725 help
726 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700727 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800728
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800729config USER_NS
730 bool "User namespace (EXPERIMENTAL)"
731 depends on NAMESPACES && EXPERIMENTAL
732 help
733 This allows containers, i.e. vservers, to use user namespaces
734 to provide different user info for different servers.
735 If unsure, say N.
736
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800737config PID_NS
738 bool "PID Namespaces (EXPERIMENTAL)"
739 default n
740 depends on NAMESPACES && EXPERIMENTAL
741 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300742 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100743 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800744 pid namespaces. This is a building block of containers.
745
746 Unless you want to work with an experimental feature
747 say N here.
748
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800749config NET_NS
750 bool "Network namespace"
751 default n
752 depends on NAMESPACES && EXPERIMENTAL && NET
753 help
754 Allow user space to create what appear to be multiple instances
755 of the network stack.
756
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800757config BLK_DEV_INITRD
758 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
759 depends on BROKEN || !FRV
760 help
761 The initial RAM filesystem is a ramfs which is loaded by the
762 boot loader (loadlin or lilo) and that is mounted as root
763 before the normal boot procedure. It is typically used to
764 load modules needed to mount the "real" root file system,
765 etc. See <file:Documentation/initrd.txt> for details.
766
767 If RAM disk support (BLK_DEV_RAM) is also included, this
768 also enables initial RAM disk (initrd) support and adds
769 15 Kbytes (more on some other architectures) to the kernel size.
770
771 If unsure say Y.
772
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800773if BLK_DEV_INITRD
774
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200775source "usr/Kconfig"
776
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800777endif
778
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800779config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200780 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800781 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800782 help
783 Enabling this option will pass "-Os" instead of "-O2" to gcc
784 resulting in a smaller kernel.
785
jkacur775a7222008-07-16 00:31:16 +0200786 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800787
Randy Dunlap08470622006-09-30 23:28:13 -0700788config SYSCTL
789 bool
790
Randy Dunlapb943c462009-03-10 12:55:46 -0700791config ANON_INODES
792 bool
793
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794menuconfig EMBEDDED
795 bool "Configure standard kernel features (for small systems)"
796 help
797 This option allows certain base kernel options and settings
798 to be disabled or tweaked. This is for specialized
799 environments which can tolerate a "non-standard" kernel.
800 Only use this if you really know what you are doing.
801
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700802config UID16
803 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700804 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 -0700805 default y
806 help
807 This enables the legacy 16-bit UID syscall wrappers.
808
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700809config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700810 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800811 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800812 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700813 select SYSCTL
814 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800815 sys_sysctl uses binary paths that have been found challenging
816 to properly maintain and use. The interface in /proc/sys
817 using paths with ascii names is now the primary path to this
818 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700819
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800820 Almost nothing using the binary sysctl interface so if you are
821 trying to save some space it is probably safe to disable this,
822 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700823
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800824 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700825
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100827 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 default y
829 help
830 Say Y here to let the kernel print out symbolic crash information and
831 symbolic stack backtraces. This increases the size of the kernel
832 somewhat, as all symbols have to be loaded into the kernel image.
833
834config KALLSYMS_ALL
835 bool "Include all symbols in kallsyms"
836 depends on DEBUG_KERNEL && KALLSYMS
837 help
838 Normally kallsyms only contains the symbols of functions, for nicer
839 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200840 symbols too: say Y here to include all symbols, if you need them
841 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 Say N.
844
845config KALLSYMS_EXTRA_PASS
846 bool "Do an extra kallsyms pass"
847 depends on KALLSYMS
848 help
849 If kallsyms is not working correctly, the build will fail with
850 inconsistent kallsyms data. If that occurs, log a bug report and
851 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
852 Always say N here unless you find a bug in kallsyms, which must be
853 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
854 you wait for kallsyms to be fixed.
855
Matt Mackalld59745c2005-05-01 08:59:02 -0700856
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800857config HOTPLUG
858 bool "Support for hot-pluggable devices" if EMBEDDED
859 default y
860 help
861 This option is provided for the case where no hotplug or uevent
862 capabilities is wanted by the kernel. You should only consider
863 disabling this option for embedded systems that do not use modules, a
864 dynamic /dev tree, or dynamic device discovery. Just say Y.
865
Matt Mackalld59745c2005-05-01 08:59:02 -0700866config PRINTK
867 default y
868 bool "Enable support for printk" if EMBEDDED
869 help
870 This option enables normal printk support. Removing it
871 eliminates most of the message strings from the kernel image
872 and makes the kernel more or less silent. As this makes it
873 very difficult to diagnose system problems, saying N here is
874 strongly discouraged.
875
Matt Mackallc8538a72005-05-01 08:59:01 -0700876config BUG
877 bool "BUG() support" if EMBEDDED
878 default y
879 help
880 Disabling this option eliminates support for BUG and WARN, reducing
881 the size of your kernel image and potentially quietly ignoring
882 numerous fatal conditions. You should only consider disabling this
883 option for embedded systems with no facilities for reporting errors.
884 Just say Y.
885
Matt Mackall708e9a72006-01-08 01:05:25 -0800886config ELF_CORE
887 default y
888 bool "Enable ELF core dumps" if EMBEDDED
889 help
890 Enable support for generating core dumps. Disabling saves about 4k.
891
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200892config PCSPKR_PLATFORM
893 bool "Enable PC-Speaker support" if EMBEDDED
894 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
895 default y
896 help
897 This option allows to disable the internal PC-Speaker
898 support, saving some memory.
899
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900config BASE_FULL
901 default y
902 bool "Enable full-sized data structures for core" if EMBEDDED
903 help
904 Disabling this option reduces the size of miscellaneous core
905 kernel data structures. This saves memory on small machines,
906 but may reduce performance.
907
908config FUTEX
909 bool "Enable futex support" if EMBEDDED
910 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700911 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 help
913 Disabling this option will cause the kernel to be built without
914 support for "fast userspace mutexes". The resulting kernel may not
915 run glibc-based applications correctly.
916
917config EPOLL
918 bool "Enable eventpoll support" if EMBEDDED
919 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700920 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 help
922 Disabling this option will cause the kernel to be built without
923 support for epoll family of system calls.
924
Davide Libenzifba2afa2007-05-10 22:23:13 -0700925config SIGNALFD
926 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700927 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700928 default y
929 help
930 Enable the signalfd() system call that allows to receive signals
931 on a file descriptor.
932
933 If unsure, say Y.
934
Davide Libenzib215e282007-05-10 22:23:16 -0700935config TIMERFD
936 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700937 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700938 default y
939 help
940 Enable the timerfd() system call that allows to receive timer
941 events on a file descriptor.
942
943 If unsure, say Y.
944
Davide Libenzie1ad7462007-05-10 22:23:19 -0700945config EVENTFD
946 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700947 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700948 default y
949 help
950 Enable the eventfd() system call that allows to receive both
951 kernel notification (ie. KAIO) or userspace notifications.
952
953 If unsure, say Y.
954
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955config SHMEM
956 bool "Use full shmem filesystem" if EMBEDDED
957 default y
958 depends on MMU
959 help
960 The shmem is an internal filesystem used to manage shared memory.
961 It is backed by swap and manages resource limits. It is also exported
962 to userspace as tmpfs if TMPFS is enabled. Disabling this
963 option replaces shmem and tmpfs with the much simpler ramfs code,
964 which may be appropriate on small systems without swap.
965
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700966config AIO
967 bool "Enable AIO support" if EMBEDDED
968 default y
969 help
970 This option enables POSIX asynchronous I/O which may by used
971 by some high performance threaded applications. Disabling
972 this option saves about 7k.
973
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200974config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100975 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400976 help
977 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100978
Peter Zijlstra906010b2009-09-21 16:08:49 +0200979config PERF_USE_VMALLOC
980 bool
981 help
982 See tools/perf/design.txt for details
983
Ingo Molnar57c0c152009-09-21 12:20:38 +0200984menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100985
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200986config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200987 bool "Kernel performance events and counters"
988 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200989 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100990 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100991 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200992 Enable kernel support for various performance events provided
993 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100994
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200995 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200996 use of generic tracepoints.
997
998 Most modern CPUs support performance events via performance
999 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001000 types of hw events: such as instructions executed, cachemisses
1001 suffered, or branches mis-predicted - without slowing down the
1002 kernel or applications. These registers can also trigger interrupts
1003 when a threshold number of events have passed - and can thus be
1004 used to profile the code that runs on that CPU.
1005
Ingo Molnar57c0c152009-09-21 12:20:38 +02001006 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001007 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001008 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001009 provides per task and per CPU counters, and it provides event
1010 capabilities on top of those.
1011
1012 Say Y if unsure.
1013
Ingo Molnar57c0c152009-09-21 12:20:38 +02001014config PERF_COUNTERS
1015 bool "Kernel performance counters (old config option)"
1016 depends on HAVE_PERF_EVENTS
1017 help
1018 This config has been obsoleted by the PERF_EVENTS
1019 config option - please see that one for details.
1020
1021 It has no effect on the kernel whether you enable
1022 it or not, it is a compatibility placeholder.
1023
1024 Say N if unsure.
1025
Peter Zijlstra906010b2009-09-21 16:08:49 +02001026config DEBUG_PERF_USE_VMALLOC
1027 default n
1028 bool "Debug: use vmalloc to back perf mmap() buffers"
1029 depends on PERF_EVENTS && DEBUG_KERNEL
1030 select PERF_USE_VMALLOC
1031 help
1032 Use vmalloc memory to back perf mmap() buffers.
1033
1034 Mostly useful for debugging the vmalloc code on platforms
1035 that don't require it.
1036
1037 Say N if unsure.
1038
Thomas Gleixner0793a612008-12-04 20:12:29 +01001039endmenu
1040
Christoph Lameterf8891e52006-06-30 01:55:45 -07001041config VM_EVENT_COUNTERS
1042 default y
1043 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1044 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001045 VM event counters are needed for event counts to be shown.
1046 This option allows the disabling of the VM event counters
1047 on EMBEDDED systems. /proc/vmstat will only show page counts
1048 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001049
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001050config PCI_QUIRKS
1051 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001052 bool "Enable PCI quirk workarounds" if EMBEDDED
1053 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001054 help
1055 This enables workarounds for various PCI chipset
1056 bugs/quirks. Disable this only if your target machine is
1057 unaffected by PCI quirks.
1058
Christoph Lameter41ecc552007-05-09 02:32:44 -07001059config SLUB_DEBUG
1060 default y
1061 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001062 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001063 help
1064 SLUB has extensive debug support features. Disabling these can
1065 result in significant savings in code size. This also disables
1066 SLUB sysfs support. /sys/slab will not exist and there will be
1067 no support for cache validation etc.
1068
Randy Dunlapb943c462009-03-10 12:55:46 -07001069config COMPAT_BRK
1070 bool "Disable heap randomization"
1071 default y
1072 help
1073 Randomizing heap placement makes heap exploits harder, but it
1074 also breaks ancient binaries (including anything libc5 based).
1075 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001076 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001077 /proc/sys/kernel/randomize_va_space to 2.
1078
1079 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1080
Christoph Lameter81819f02007-05-06 14:49:36 -07001081choice
1082 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001083 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001084 help
1085 This option allows to select a slab allocator.
1086
1087config SLAB
1088 bool "SLAB"
1089 help
1090 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001091 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001092 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001093
1094config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001095 bool "SLUB (Unqueued Allocator)"
1096 help
1097 SLUB is a slab allocator that minimizes cache line usage
1098 instead of managing queues of cached objects (SLAB approach).
1099 Per cpu caching is realized using slabs of objects instead
1100 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001101 and has enhanced diagnostics. SLUB is the default choice for
1102 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001103
1104config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001105 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001106 bool "SLOB (Simple Allocator)"
1107 help
Matt Mackall37291452008-02-04 22:29:38 -08001108 SLOB replaces the stock allocator with a drastically simpler
1109 allocator. SLOB is generally more space efficient but
1110 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001111
1112endchoice
1113
Jie Zhangea637632009-12-14 18:00:02 -08001114config MMAP_ALLOW_UNINITIALIZED
1115 bool "Allow mmapped anonymous memory to be uninitialized"
1116 depends on EMBEDDED && !MMU
1117 default n
1118 help
1119 Normally, and according to the Linux spec, anonymous memory obtained
1120 from mmap() has it's contents cleared before it is passed to
1121 userspace. Enabling this config option allows you to request that
1122 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1123 providing a huge performance boost. If this option is not enabled,
1124 then the flag will be ignored.
1125
1126 This is taken advantage of by uClibc's malloc(), and also by
1127 ELF-FDPIC binfmt's brk and stack allocator.
1128
1129 Because of the obvious security issues, this option should only be
1130 enabled on embedded devices where you control what is run in
1131 userspace. Since that isn't generally a problem on no-MMU systems,
1132 it is normally safe to say Y here.
1133
1134 See Documentation/nommu-mmap.txt for more information.
1135
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001136config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001137 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001138 help
1139 Say Y here to enable the extended profiling support mechanisms used
1140 by profilers such as OProfile.
1141
Ingo Molnar5f87f112008-07-23 14:15:22 +02001142#
1143# Place an empty function call at each tracepoint site. Can be
1144# dynamically changed for a probe function.
1145#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001146config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001147 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001148
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001149source "arch/Kconfig"
1150
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151endmenu # General setup
1152
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001153config HAVE_GENERIC_DMA_COHERENT
1154 bool
1155 default n
1156
Linus Torvalds158a9622008-01-02 13:04:48 -08001157config SLABINFO
1158 bool
1159 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001160 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001161 default y
1162
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001163config RT_MUTEXES
1164 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001165
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166config BASE_SMALL
1167 int
1168 default 0 if BASE_FULL
1169 default 1 if !BASE_FULL
1170
Jan Engelhardt66da5732007-07-15 23:39:29 -07001171menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 bool "Enable loadable module support"
1173 help
1174 Kernel modules are small pieces of compiled code which can
1175 be inserted in the running kernel, rather than being
1176 permanently built into the kernel. You use the "modprobe"
1177 tool to add (and sometimes remove) them. If you say Y here,
1178 many parts of the kernel can be built as modules (by
1179 answering M instead of Y where indicated): this is most
1180 useful for infrequently used options which are not required
1181 for booting. For more information, see the man pages for
1182 modprobe, lsmod, modinfo, insmod and rmmod.
1183
1184 If you say Y here, you will need to run "make
1185 modules_install" to put the modules under /lib/modules/
1186 where modprobe can find them (you may need to be root to do
1187 this).
1188
1189 If unsure, say Y.
1190
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001191if MODULES
1192
Linus Torvalds826e4502008-05-04 17:04:16 -07001193config MODULE_FORCE_LOAD
1194 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001195 default n
1196 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001197 Allow loading of modules without version information (ie. modprobe
1198 --force). Forced module loading sets the 'F' (forced) taint flag and
1199 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001200
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201config MODULE_UNLOAD
1202 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 help
1204 Without this option you will not be able to unload any
1205 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001206 anyway), which makes your kernel smaller, faster
1207 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208
1209config MODULE_FORCE_UNLOAD
1210 bool "Forced module unloading"
1211 depends on MODULE_UNLOAD && EXPERIMENTAL
1212 help
1213 This option allows you to force a module to unload, even if the
1214 kernel believes it is unsafe: the kernel will remove the module
1215 without waiting for anyone to stop using it (using the -f option to
1216 rmmod). This is mainly for kernel developers and desperate users.
1217 If unsure, say N.
1218
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001220 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 help
1222 Usually, you have to use modules compiled with your kernel.
1223 Saying Y here makes it sometimes possible to use modules
1224 compiled for different kernels, by adding enough information
1225 to the modules to (hopefully) spot any changes which would
1226 make them incompatible with the kernel you are running. If
1227 unsure, say N.
1228
1229config MODULE_SRCVERSION_ALL
1230 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 help
1232 Modules which contain a MODULE_VERSION get an extra "srcversion"
1233 field inserted into their modinfo section, which contains a
1234 sum of the source files which made it. This helps maintainers
1235 see exactly which source was used to build a module (since
1236 others sometimes change the module source without updating
1237 the version). With this option, such a "srcversion" field
1238 will be created for all modules. If unsure, say N.
1239
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001240endif # MODULES
1241
Rusty Russell98a79d62008-12-13 21:19:41 +10301242config INIT_ALL_POSSIBLE
1243 bool
1244 help
1245 Back when each arch used to define their own cpu_online_map and
1246 cpu_possible_map, some of them chose to initialize cpu_possible_map
1247 with all 1s, and others with all 0s. When they were centralised,
1248 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001249 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301250
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251config STOP_MACHINE
1252 bool
1253 default y
1254 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1255 help
1256 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001257
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001258source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001259
1260config PREEMPT_NOTIFIERS
1261 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001262
Steffen Klassert16295be2010-01-06 19:47:10 +11001263config PADATA
1264 depends on SMP
1265 bool
1266
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001267source "kernel/Kconfig.locks"