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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
22 default y
23
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47 drivers that have been replaced by something else, and/or are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,
Amy Griffisf368c07d2006-04-07 16:55:56 -0400323 such as SELinux. To use audit's filesystem watch feature, please
324 ensure that INOTIFY is configured.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
Al Viro74c3cbe2007-07-22 08:04:18 -0400326config AUDIT_TREE
327 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400328 depends on AUDITSYSCALL
329 select INOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400330
Mike Travisc903ff82009-01-15 12:28:29 -0800331menu "RCU Subsystem"
332
333choice
334 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700335 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800336
Mike Travisc903ff82009-01-15 12:28:29 -0800337config TREE_RCU
338 bool "Tree-based hierarchical RCU"
339 help
340 This option selects the RCU implementation that is
341 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700342 thousands of CPUs. It also scales down nicely to
343 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800344
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700345config TREE_PREEMPT_RCU
346 bool "Preemptable tree-based hierarchical RCU"
347 depends on PREEMPT
348 help
349 This option selects the RCU implementation that is
350 designed for very large SMP systems with hundreds or
351 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700352 is also required. It also scales down nicely to
353 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700354
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700355config TINY_RCU
356 bool "UP-only small-memory-footprint RCU"
357 depends on !SMP
358 help
359 This option selects the RCU implementation that is
360 designed for UP systems from which real-time response
361 is not required. This option greatly reduces the
362 memory footprint of RCU.
363
Mike Travisc903ff82009-01-15 12:28:29 -0800364endchoice
365
366config RCU_TRACE
367 bool "Enable tracing for RCU"
Paul E. McKenney6b3ef482009-08-22 13:56:53 -0700368 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800369 help
370 This option provides tracing in RCU which presents stats
371 in debugfs for debugging RCU implementation.
372
373 Say Y here if you want to enable RCU tracing
374 Say N if you are unsure.
375
376config RCU_FANOUT
377 int "Tree-based hierarchical RCU fanout value"
378 range 2 64 if 64BIT
379 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700380 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800381 default 64 if 64BIT
382 default 32 if !64BIT
383 help
384 This option controls the fanout of hierarchical implementations
385 of RCU, allowing RCU to work efficiently on machines with
386 large numbers of CPUs. This value must be at least the cube
387 root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
388 systems and up to 262,144 for 64-bit systems.
389
390 Select a specific number if testing RCU itself.
391 Take the default if unsure.
392
393config RCU_FANOUT_EXACT
394 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700395 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800396 default n
397 help
398 This option forces use of the exact RCU_FANOUT value specified,
399 regardless of imbalances in the hierarchy. This is useful for
400 testing RCU itself, and might one day be useful on systems with
401 strong NUMA behavior.
402
403 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
404
405 Say N if unsure.
406
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800407config RCU_FAST_NO_HZ
408 bool "Accelerate last non-dyntick-idle CPU's grace periods"
409 depends on TREE_RCU && NO_HZ && SMP
410 default n
411 help
412 This option causes RCU to attempt to accelerate grace periods
413 in order to allow the final CPU to enter dynticks-idle state
414 more quickly. On the other hand, this option increases the
415 overhead of the dynticks-idle checking, particularly on systems
416 with large numbers of CPUs.
417
418 Say Y if energy efficiency is critically important, particularly
419 if you have relatively few CPUs.
420
421 Say N if you are unsure.
422
Mike Travisc903ff82009-01-15 12:28:29 -0800423config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700424 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800425 select DEBUG_FS
426 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700427 This option provides tracing for the TREE_RCU and
428 TREE_PREEMPT_RCU implementations, permitting Makefile to
429 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800430
Mike Travisc903ff82009-01-15 12:28:29 -0800431endmenu # "RCU Subsystem"
432
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700434 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 ---help---
436 This option enables the complete Linux kernel ".config" file
437 contents to be saved in the kernel. It provides documentation
438 of which kernel options are used in a running kernel or in an
439 on-disk kernel. This information can be extracted from the kernel
440 image file with the script scripts/extract-ikconfig and used as
441 input to rebuild the current kernel or to build another kernel.
442 It can also be extracted from a running kernel by reading
443 /proc/config.gz if enabled (below).
444
445config IKCONFIG_PROC
446 bool "Enable access to .config through /proc/config.gz"
447 depends on IKCONFIG && PROC_FS
448 ---help---
449 This option enables access to the kernel configuration file
450 through /proc/config.gz.
451
Alistair John Strachan794543a2007-05-08 00:31:15 -0700452config LOG_BUF_SHIFT
453 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
454 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700455 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700456 help
457 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700458 Examples:
459 17 => 128 KB
460 16 => 64 KB
461 15 => 32 KB
462 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700463 13 => 8 KB
464 12 => 4 KB
465
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800466#
467# Architectures with an unreliable sched_clock() should select this:
468#
469config HAVE_UNSTABLE_SCHED_CLOCK
470 bool
471
Li Zefan23964d22009-01-15 13:50:58 -0800472menuconfig CGROUPS
473 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800474 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700475 help
Li Zefan23964d22009-01-15 13:50:58 -0800476 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800477 use with process control subsystems such as Cpusets, CFS, memory
478 controls or device isolation.
479 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800480 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800481 - Documentation/cgroups/ (features for grouping, isolation
482 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700483
484 Say N if unsure.
485
Li Zefan23964d22009-01-15 13:50:58 -0800486if CGROUPS
487
Paul Menage006cb992007-10-18 23:39:43 -0700488config CGROUP_DEBUG
489 bool "Example debug cgroup subsystem"
490 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700491 default n
Paul Menage006cb992007-10-18 23:39:43 -0700492 help
493 This option enables a simple cgroup subsystem that
494 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800495 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700496
Li Zefan23964d22009-01-15 13:50:58 -0800497 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700498
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700499config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800500 bool "Namespace cgroup subsystem"
501 depends on CGROUPS
502 help
503 Provides a simple namespace cgroup subsystem to
504 provide hierarchical naming of sets of namespaces,
505 for instance virtual servers and checkpoint/restart
506 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700507
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700508config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800509 bool "Freezer cgroup subsystem"
510 depends on CGROUPS
511 help
512 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700513 cgroup.
514
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700515config CGROUP_DEVICE
516 bool "Device controller for cgroups"
517 depends on CGROUPS && EXPERIMENTAL
518 help
519 Provides a cgroup implementing whitelists for devices which
520 a process in the cgroup can mknod or open.
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522config CPUSETS
523 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700524 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700526 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 allow dynamically partitioning a system into sets of CPUs and
528 Memory Nodes and assigning tasks to run only within those sets.
529 This is primarily useful on large SMP or NUMA systems.
530
531 Say N if unsure.
532
Li Zefan23964d22009-01-15 13:50:58 -0800533config PROC_PID_CPUSET
534 bool "Include legacy /proc/<pid>/cpuset file"
535 depends on CPUSETS
536 default y
537
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100538config CGROUP_CPUACCT
539 bool "Simple CPU accounting cgroup subsystem"
540 depends on CGROUPS
541 help
542 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800543 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100544
Pavel Emelianove552b662008-02-07 00:13:49 -0800545config RESOURCE_COUNTERS
546 bool "Resource counters"
547 help
548 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800549 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800550 depends on CGROUPS
551
Balbir Singh00f0b822008-03-04 14:28:39 -0800552config CGROUP_MEM_RES_CTLR
553 bool "Memory Resource Controller for Control Groups"
554 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700555 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800556 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700557 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100558 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800559
560 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700561 associated with each page of memory in the system. By this,
562 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
563 usage tracking struct at boot. Total amount of this is printed out
564 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800565
566 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700567 sure you need the memory resource controller. Even when you enable
568 this, you can set "cgroup_disable=memory" at your boot option to
569 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800570 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800571
Balbir Singhcf475ad2008-04-29 01:00:16 -0700572 This config option also selects MM_OWNER config option, which
573 could in turn add some fork/exit overhead.
574
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800575config CGROUP_MEM_RES_CTLR_SWAP
576 bool "Memory Resource Controller Swap Extension(EXPERIMENTAL)"
577 depends on CGROUP_MEM_RES_CTLR && SWAP && EXPERIMENTAL
578 help
579 Add swap management feature to memory resource controller. When you
580 enable this, you can limit mem+swap usage per cgroup. In other words,
581 when you disable this, memory resource controller has no cares to
582 usage of swap...a process can exhaust all of the swap. This extension
583 is useful when you want to avoid exhaustion swap but this itself
584 adds more overheads and consumes memory for remembering information.
585 Especially if you use 32bit system or small memory system, please
586 be careful about enabling this. When memory resource controller
587 is disabled by boot option, this will be automatically disabled and
588 there will be no overhead from this. Even when you set this config=y,
589 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700590 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
591 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800592
Dhaval Giani7c941432010-01-20 13:26:18 +0100593menuconfig CGROUP_SCHED
594 bool "Group CPU scheduler"
595 depends on EXPERIMENTAL && CGROUPS
596 default n
597 help
598 This feature lets CPU scheduler recognize task groups and control CPU
599 bandwidth allocation to such task groups. It uses cgroups to group
600 tasks.
601
602if CGROUP_SCHED
603config FAIR_GROUP_SCHED
604 bool "Group scheduling for SCHED_OTHER"
605 depends on CGROUP_SCHED
606 default CGROUP_SCHED
607
608config RT_GROUP_SCHED
609 bool "Group scheduling for SCHED_RR/FIFO"
610 depends on EXPERIMENTAL
611 depends on CGROUP_SCHED
612 default n
613 help
614 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800615 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100616 schedule realtime tasks for non-root users until you allocate
617 realtime bandwidth for them.
618 See Documentation/scheduler/sched-rt-group.txt for more information.
619
620endif #CGROUP_SCHED
621
Vivek Goyalafc24d42010-04-26 19:27:56 +0200622config BLK_CGROUP
623 tristate "Block IO controller"
624 depends on CGROUPS && BLOCK
625 default n
626 ---help---
627 Generic block IO controller cgroup interface. This is the common
628 cgroup interface which should be used by various IO controlling
629 policies.
630
631 Currently, CFQ IO scheduler uses it to recognize task groups and
632 control disk bandwidth allocation (proportional time slice allocation)
633 to such task groups.
634
635 This option only enables generic Block IO controller infrastructure.
636 One needs to also enable actual IO controlling logic in CFQ for it
637 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
638
639 See Documentation/cgroups/blkio-controller.txt for more information.
640
641config DEBUG_BLK_CGROUP
642 bool "Enable Block IO controller debugging"
643 depends on BLK_CGROUP
644 default n
645 ---help---
646 Enable some debugging help. Currently it exports additional stat
647 files in a cgroup which can be useful for debugging.
648
Li Zefan23964d22009-01-15 13:50:58 -0800649endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800650
Li Zefan23964d22009-01-15 13:50:58 -0800651config MM_OWNER
652 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800653
Kay Sievers88a22c92006-09-14 11:23:28 +0200654config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100655 bool
656
657config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100658 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800659 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200660 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100661 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200662 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100663 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200664 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200665
Kay Sieversfce3e802008-11-01 14:03:00 +0100666 The current sysfs layout features a unified device tree at
667 /sys/devices/, which is able to express a hierarchy between
668 class devices. If the deprecated option is set to Y, the
669 unified device tree is split into a bus device tree at
670 /sys/devices/ and several individual class device trees at
671 /sys/class/. The class and bus devices will be connected by
672 "<subsystem>:<name>" and the "device" links. The "block"
673 class devices, will not show up in /sys/class/block/. Some
674 subsystems will suppress the creation of some devices which
675 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200676
Kay Sieversfce3e802008-11-01 14:03:00 +0100677 This option is not a pure compatibility option that can
678 be safely enabled on newer distributions. It will change the
679 layout of sysfs to the non-extensible deprecated version,
680 and disable some features, which can not be exported without
681 confusing older userspace tools. Since 2007/2008 all major
682 distributions do not enable this option, and ship no tools which
683 depend on the deprecated layout or this option.
684
685 If you are using a new kernel on an older distribution, or use
686 older userspace tools, you might need to say Y here. Do not say Y,
687 if the original kernel, that came with your distribution, has
688 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200689
Jens Axboeb86ff9812006-03-23 19:56:55 +0100690config RELAY
691 bool "Kernel->user space relay support (formerly relayfs)"
692 help
693 This option enables support for relay interface support in
694 certain file systems (such as debugfs).
695 It is designed to provide an efficient mechanism for tools and
696 facilities to relay large amounts of data from kernel space to
697 user space.
698
699 If unsure, say N.
700
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800701config NAMESPACES
702 bool "Namespaces support" if EMBEDDED
703 default !EMBEDDED
704 help
705 Provides the way to make tasks work with different objects using
706 the same id. For example same IPC id may refer to different objects
707 or same user id or pid may refer to different tasks when used in
708 different namespaces.
709
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800710config UTS_NS
711 bool "UTS namespace"
712 depends on NAMESPACES
713 help
714 In this namespace tasks see different info provided with the
715 uname() system call
716
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800717config IPC_NS
718 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700719 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800720 help
721 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700722 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800723
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800724config USER_NS
725 bool "User namespace (EXPERIMENTAL)"
726 depends on NAMESPACES && EXPERIMENTAL
727 help
728 This allows containers, i.e. vservers, to use user namespaces
729 to provide different user info for different servers.
730 If unsure, say N.
731
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800732config PID_NS
733 bool "PID Namespaces (EXPERIMENTAL)"
734 default n
735 depends on NAMESPACES && EXPERIMENTAL
736 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300737 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100738 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800739 pid namespaces. This is a building block of containers.
740
741 Unless you want to work with an experimental feature
742 say N here.
743
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800744config NET_NS
745 bool "Network namespace"
746 default n
747 depends on NAMESPACES && EXPERIMENTAL && NET
748 help
749 Allow user space to create what appear to be multiple instances
750 of the network stack.
751
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800752config BLK_DEV_INITRD
753 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
754 depends on BROKEN || !FRV
755 help
756 The initial RAM filesystem is a ramfs which is loaded by the
757 boot loader (loadlin or lilo) and that is mounted as root
758 before the normal boot procedure. It is typically used to
759 load modules needed to mount the "real" root file system,
760 etc. See <file:Documentation/initrd.txt> for details.
761
762 If RAM disk support (BLK_DEV_RAM) is also included, this
763 also enables initial RAM disk (initrd) support and adds
764 15 Kbytes (more on some other architectures) to the kernel size.
765
766 If unsure say Y.
767
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800768if BLK_DEV_INITRD
769
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200770source "usr/Kconfig"
771
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800772endif
773
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800774config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200775 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800776 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800777 help
778 Enabling this option will pass "-Os" instead of "-O2" to gcc
779 resulting in a smaller kernel.
780
jkacur775a7222008-07-16 00:31:16 +0200781 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800782
Randy Dunlap08470622006-09-30 23:28:13 -0700783config SYSCTL
784 bool
785
Randy Dunlapb943c462009-03-10 12:55:46 -0700786config ANON_INODES
787 bool
788
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789menuconfig EMBEDDED
790 bool "Configure standard kernel features (for small systems)"
791 help
792 This option allows certain base kernel options and settings
793 to be disabled or tweaked. This is for specialized
794 environments which can tolerate a "non-standard" kernel.
795 Only use this if you really know what you are doing.
796
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700797config UID16
798 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700799 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 -0700800 default y
801 help
802 This enables the legacy 16-bit UID syscall wrappers.
803
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700804config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700805 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800806 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800807 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700808 select SYSCTL
809 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800810 sys_sysctl uses binary paths that have been found challenging
811 to properly maintain and use. The interface in /proc/sys
812 using paths with ascii names is now the primary path to this
813 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700814
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800815 Almost nothing using the binary sysctl interface so if you are
816 trying to save some space it is probably safe to disable this,
817 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700818
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800819 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700820
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100822 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 default y
824 help
825 Say Y here to let the kernel print out symbolic crash information and
826 symbolic stack backtraces. This increases the size of the kernel
827 somewhat, as all symbols have to be loaded into the kernel image.
828
829config KALLSYMS_ALL
830 bool "Include all symbols in kallsyms"
831 depends on DEBUG_KERNEL && KALLSYMS
832 help
833 Normally kallsyms only contains the symbols of functions, for nicer
834 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200835 symbols too: say Y here to include all symbols, if you need them
836 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
838 Say N.
839
840config KALLSYMS_EXTRA_PASS
841 bool "Do an extra kallsyms pass"
842 depends on KALLSYMS
843 help
844 If kallsyms is not working correctly, the build will fail with
845 inconsistent kallsyms data. If that occurs, log a bug report and
846 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
847 Always say N here unless you find a bug in kallsyms, which must be
848 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
849 you wait for kallsyms to be fixed.
850
Matt Mackalld59745c2005-05-01 08:59:02 -0700851
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800852config HOTPLUG
853 bool "Support for hot-pluggable devices" if EMBEDDED
854 default y
855 help
856 This option is provided for the case where no hotplug or uevent
857 capabilities is wanted by the kernel. You should only consider
858 disabling this option for embedded systems that do not use modules, a
859 dynamic /dev tree, or dynamic device discovery. Just say Y.
860
Matt Mackalld59745c2005-05-01 08:59:02 -0700861config PRINTK
862 default y
863 bool "Enable support for printk" if EMBEDDED
864 help
865 This option enables normal printk support. Removing it
866 eliminates most of the message strings from the kernel image
867 and makes the kernel more or less silent. As this makes it
868 very difficult to diagnose system problems, saying N here is
869 strongly discouraged.
870
Matt Mackallc8538a72005-05-01 08:59:01 -0700871config BUG
872 bool "BUG() support" if EMBEDDED
873 default y
874 help
875 Disabling this option eliminates support for BUG and WARN, reducing
876 the size of your kernel image and potentially quietly ignoring
877 numerous fatal conditions. You should only consider disabling this
878 option for embedded systems with no facilities for reporting errors.
879 Just say Y.
880
Matt Mackall708e9a72006-01-08 01:05:25 -0800881config ELF_CORE
882 default y
883 bool "Enable ELF core dumps" if EMBEDDED
884 help
885 Enable support for generating core dumps. Disabling saves about 4k.
886
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200887config PCSPKR_PLATFORM
888 bool "Enable PC-Speaker support" if EMBEDDED
889 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
890 default y
891 help
892 This option allows to disable the internal PC-Speaker
893 support, saving some memory.
894
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895config BASE_FULL
896 default y
897 bool "Enable full-sized data structures for core" if EMBEDDED
898 help
899 Disabling this option reduces the size of miscellaneous core
900 kernel data structures. This saves memory on small machines,
901 but may reduce performance.
902
903config FUTEX
904 bool "Enable futex support" if EMBEDDED
905 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700906 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 help
908 Disabling this option will cause the kernel to be built without
909 support for "fast userspace mutexes". The resulting kernel may not
910 run glibc-based applications correctly.
911
912config EPOLL
913 bool "Enable eventpoll support" if EMBEDDED
914 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700915 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 help
917 Disabling this option will cause the kernel to be built without
918 support for epoll family of system calls.
919
Davide Libenzifba2afa2007-05-10 22:23:13 -0700920config SIGNALFD
921 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700922 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700923 default y
924 help
925 Enable the signalfd() system call that allows to receive signals
926 on a file descriptor.
927
928 If unsure, say Y.
929
Davide Libenzib215e282007-05-10 22:23:16 -0700930config TIMERFD
931 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700932 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700933 default y
934 help
935 Enable the timerfd() system call that allows to receive timer
936 events on a file descriptor.
937
938 If unsure, say Y.
939
Davide Libenzie1ad7462007-05-10 22:23:19 -0700940config EVENTFD
941 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700942 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700943 default y
944 help
945 Enable the eventfd() system call that allows to receive both
946 kernel notification (ie. KAIO) or userspace notifications.
947
948 If unsure, say Y.
949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950config SHMEM
951 bool "Use full shmem filesystem" if EMBEDDED
952 default y
953 depends on MMU
954 help
955 The shmem is an internal filesystem used to manage shared memory.
956 It is backed by swap and manages resource limits. It is also exported
957 to userspace as tmpfs if TMPFS is enabled. Disabling this
958 option replaces shmem and tmpfs with the much simpler ramfs code,
959 which may be appropriate on small systems without swap.
960
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700961config AIO
962 bool "Enable AIO support" if EMBEDDED
963 default y
964 help
965 This option enables POSIX asynchronous I/O which may by used
966 by some high performance threaded applications. Disabling
967 this option saves about 7k.
968
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200969config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100970 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400971 help
972 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100973
Peter Zijlstra906010b2009-09-21 16:08:49 +0200974config PERF_USE_VMALLOC
975 bool
976 help
977 See tools/perf/design.txt for details
978
Ingo Molnar57c0c152009-09-21 12:20:38 +0200979menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100980
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200981config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200982 bool "Kernel performance events and counters"
983 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200984 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100985 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100986 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200987 Enable kernel support for various performance events provided
988 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100989
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200990 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200991 use of generic tracepoints.
992
993 Most modern CPUs support performance events via performance
994 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +0100995 types of hw events: such as instructions executed, cachemisses
996 suffered, or branches mis-predicted - without slowing down the
997 kernel or applications. These registers can also trigger interrupts
998 when a threshold number of events have passed - and can thus be
999 used to profile the code that runs on that CPU.
1000
Ingo Molnar57c0c152009-09-21 12:20:38 +02001001 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001002 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001003 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001004 provides per task and per CPU counters, and it provides event
1005 capabilities on top of those.
1006
1007 Say Y if unsure.
1008
Ingo Molnar57c0c152009-09-21 12:20:38 +02001009config PERF_COUNTERS
1010 bool "Kernel performance counters (old config option)"
1011 depends on HAVE_PERF_EVENTS
1012 help
1013 This config has been obsoleted by the PERF_EVENTS
1014 config option - please see that one for details.
1015
1016 It has no effect on the kernel whether you enable
1017 it or not, it is a compatibility placeholder.
1018
1019 Say N if unsure.
1020
Peter Zijlstra906010b2009-09-21 16:08:49 +02001021config DEBUG_PERF_USE_VMALLOC
1022 default n
1023 bool "Debug: use vmalloc to back perf mmap() buffers"
1024 depends on PERF_EVENTS && DEBUG_KERNEL
1025 select PERF_USE_VMALLOC
1026 help
1027 Use vmalloc memory to back perf mmap() buffers.
1028
1029 Mostly useful for debugging the vmalloc code on platforms
1030 that don't require it.
1031
1032 Say N if unsure.
1033
Thomas Gleixner0793a612008-12-04 20:12:29 +01001034endmenu
1035
Christoph Lameterf8891e52006-06-30 01:55:45 -07001036config VM_EVENT_COUNTERS
1037 default y
1038 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1039 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001040 VM event counters are needed for event counts to be shown.
1041 This option allows the disabling of the VM event counters
1042 on EMBEDDED systems. /proc/vmstat will only show page counts
1043 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001044
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001045config PCI_QUIRKS
1046 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001047 bool "Enable PCI quirk workarounds" if EMBEDDED
1048 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001049 help
1050 This enables workarounds for various PCI chipset
1051 bugs/quirks. Disable this only if your target machine is
1052 unaffected by PCI quirks.
1053
Christoph Lameter41ecc552007-05-09 02:32:44 -07001054config SLUB_DEBUG
1055 default y
1056 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001057 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001058 help
1059 SLUB has extensive debug support features. Disabling these can
1060 result in significant savings in code size. This also disables
1061 SLUB sysfs support. /sys/slab will not exist and there will be
1062 no support for cache validation etc.
1063
Randy Dunlapb943c462009-03-10 12:55:46 -07001064config COMPAT_BRK
1065 bool "Disable heap randomization"
1066 default y
1067 help
1068 Randomizing heap placement makes heap exploits harder, but it
1069 also breaks ancient binaries (including anything libc5 based).
1070 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001071 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001072 /proc/sys/kernel/randomize_va_space to 2.
1073
1074 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1075
Christoph Lameter81819f02007-05-06 14:49:36 -07001076choice
1077 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001078 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001079 help
1080 This option allows to select a slab allocator.
1081
1082config SLAB
1083 bool "SLAB"
1084 help
1085 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001086 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001087 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001088
1089config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001090 bool "SLUB (Unqueued Allocator)"
1091 help
1092 SLUB is a slab allocator that minimizes cache line usage
1093 instead of managing queues of cached objects (SLAB approach).
1094 Per cpu caching is realized using slabs of objects instead
1095 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001096 and has enhanced diagnostics. SLUB is the default choice for
1097 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001098
1099config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001100 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001101 bool "SLOB (Simple Allocator)"
1102 help
Matt Mackall37291452008-02-04 22:29:38 -08001103 SLOB replaces the stock allocator with a drastically simpler
1104 allocator. SLOB is generally more space efficient but
1105 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001106
1107endchoice
1108
Jie Zhangea637632009-12-14 18:00:02 -08001109config MMAP_ALLOW_UNINITIALIZED
1110 bool "Allow mmapped anonymous memory to be uninitialized"
1111 depends on EMBEDDED && !MMU
1112 default n
1113 help
1114 Normally, and according to the Linux spec, anonymous memory obtained
1115 from mmap() has it's contents cleared before it is passed to
1116 userspace. Enabling this config option allows you to request that
1117 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1118 providing a huge performance boost. If this option is not enabled,
1119 then the flag will be ignored.
1120
1121 This is taken advantage of by uClibc's malloc(), and also by
1122 ELF-FDPIC binfmt's brk and stack allocator.
1123
1124 Because of the obvious security issues, this option should only be
1125 enabled on embedded devices where you control what is run in
1126 userspace. Since that isn't generally a problem on no-MMU systems,
1127 it is normally safe to say Y here.
1128
1129 See Documentation/nommu-mmap.txt for more information.
1130
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001131config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001132 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001133 help
1134 Say Y here to enable the extended profiling support mechanisms used
1135 by profilers such as OProfile.
1136
Ingo Molnar5f87f112008-07-23 14:15:22 +02001137#
1138# Place an empty function call at each tracepoint site. Can be
1139# dynamically changed for a probe function.
1140#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001141config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001142 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001143
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001144source "arch/Kconfig"
1145
David Howells07fe7cb2009-04-03 16:42:35 +01001146config SLOW_WORK
1147 default n
David Howells1c2d0082009-04-06 15:47:25 +01001148 bool
David Howells07fe7cb2009-04-03 16:42:35 +01001149 help
1150 The slow work thread pool provides a number of dynamically allocated
1151 threads that can be used by the kernel to perform operations that
1152 take a relatively long time.
1153
1154 An example of this would be CacheFiles doing a path lookup followed
1155 by a series of mkdirs and a create call, all of which have to touch
1156 disk.
1157
David Howells1c2d0082009-04-06 15:47:25 +01001158 See Documentation/slow-work.txt.
1159
David Howellsf13a48b2009-12-01 15:36:11 +00001160config SLOW_WORK_DEBUG
1161 bool "Slow work debugging through debugfs"
David Howells8fba10a2009-11-19 18:10:51 +00001162 default n
David Howellsf13a48b2009-12-01 15:36:11 +00001163 depends on SLOW_WORK && DEBUG_FS
David Howells8fba10a2009-11-19 18:10:51 +00001164 help
David Howellsf13a48b2009-12-01 15:36:11 +00001165 Display the contents of the slow work run queue through debugfs,
David Howells8fba10a2009-11-19 18:10:51 +00001166 including items currently executing.
1167
1168 See Documentation/slow-work.txt.
1169
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170endmenu # General setup
1171
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001172config HAVE_GENERIC_DMA_COHERENT
1173 bool
1174 default n
1175
Linus Torvalds158a9622008-01-02 13:04:48 -08001176config SLABINFO
1177 bool
1178 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001179 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001180 default y
1181
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001182config RT_MUTEXES
1183 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001184
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185config BASE_SMALL
1186 int
1187 default 0 if BASE_FULL
1188 default 1 if !BASE_FULL
1189
Jan Engelhardt66da5732007-07-15 23:39:29 -07001190menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 bool "Enable loadable module support"
1192 help
1193 Kernel modules are small pieces of compiled code which can
1194 be inserted in the running kernel, rather than being
1195 permanently built into the kernel. You use the "modprobe"
1196 tool to add (and sometimes remove) them. If you say Y here,
1197 many parts of the kernel can be built as modules (by
1198 answering M instead of Y where indicated): this is most
1199 useful for infrequently used options which are not required
1200 for booting. For more information, see the man pages for
1201 modprobe, lsmod, modinfo, insmod and rmmod.
1202
1203 If you say Y here, you will need to run "make
1204 modules_install" to put the modules under /lib/modules/
1205 where modprobe can find them (you may need to be root to do
1206 this).
1207
1208 If unsure, say Y.
1209
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001210if MODULES
1211
Linus Torvalds826e4502008-05-04 17:04:16 -07001212config MODULE_FORCE_LOAD
1213 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001214 default n
1215 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001216 Allow loading of modules without version information (ie. modprobe
1217 --force). Forced module loading sets the 'F' (forced) taint flag and
1218 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001219
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220config MODULE_UNLOAD
1221 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 help
1223 Without this option you will not be able to unload any
1224 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001225 anyway), which makes your kernel smaller, faster
1226 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
1228config MODULE_FORCE_UNLOAD
1229 bool "Forced module unloading"
1230 depends on MODULE_UNLOAD && EXPERIMENTAL
1231 help
1232 This option allows you to force a module to unload, even if the
1233 kernel believes it is unsafe: the kernel will remove the module
1234 without waiting for anyone to stop using it (using the -f option to
1235 rmmod). This is mainly for kernel developers and desperate users.
1236 If unsure, say N.
1237
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001239 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 help
1241 Usually, you have to use modules compiled with your kernel.
1242 Saying Y here makes it sometimes possible to use modules
1243 compiled for different kernels, by adding enough information
1244 to the modules to (hopefully) spot any changes which would
1245 make them incompatible with the kernel you are running. If
1246 unsure, say N.
1247
1248config MODULE_SRCVERSION_ALL
1249 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 help
1251 Modules which contain a MODULE_VERSION get an extra "srcversion"
1252 field inserted into their modinfo section, which contains a
1253 sum of the source files which made it. This helps maintainers
1254 see exactly which source was used to build a module (since
1255 others sometimes change the module source without updating
1256 the version). With this option, such a "srcversion" field
1257 will be created for all modules. If unsure, say N.
1258
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001259endif # MODULES
1260
Rusty Russell98a79d62008-12-13 21:19:41 +10301261config INIT_ALL_POSSIBLE
1262 bool
1263 help
1264 Back when each arch used to define their own cpu_online_map and
1265 cpu_possible_map, some of them chose to initialize cpu_possible_map
1266 with all 1s, and others with all 0s. When they were centralised,
1267 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001268 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301269
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270config STOP_MACHINE
1271 bool
1272 default y
1273 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1274 help
1275 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001276
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001277source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001278
1279config PREEMPT_NOTIFIERS
1280 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001281
Steffen Klassert16295be2010-01-06 19:47:10 +11001282config PADATA
1283 depends on SMP
1284 bool
1285
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001286source "kernel/Kconfig.locks"