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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47 drivers that have been replaced by something else, and/or are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,
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
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700391 large numbers of CPUs. This value must be at least the fourth
392 root of NR_CPUS, which allows NR_CPUS to be insanely large.
393 The default value of RCU_FANOUT should be used for production
394 systems, but if you are stress-testing the RCU implementation
395 itself, small RCU_FANOUT values allow you to test large-system
396 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800397
398 Select a specific number if testing RCU itself.
399 Take the default if unsure.
400
401config RCU_FANOUT_EXACT
402 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700403 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800404 default n
405 help
406 This option forces use of the exact RCU_FANOUT value specified,
407 regardless of imbalances in the hierarchy. This is useful for
408 testing RCU itself, and might one day be useful on systems with
409 strong NUMA behavior.
410
411 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
412
413 Say N if unsure.
414
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800415config RCU_FAST_NO_HZ
416 bool "Accelerate last non-dyntick-idle CPU's grace periods"
417 depends on TREE_RCU && NO_HZ && SMP
418 default n
419 help
420 This option causes RCU to attempt to accelerate grace periods
421 in order to allow the final CPU to enter dynticks-idle state
422 more quickly. On the other hand, this option increases the
423 overhead of the dynticks-idle checking, particularly on systems
424 with large numbers of CPUs.
425
426 Say Y if energy efficiency is critically important, particularly
427 if you have relatively few CPUs.
428
429 Say N if you are unsure.
430
Mike Travisc903ff82009-01-15 12:28:29 -0800431config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700432 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800433 select DEBUG_FS
434 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700435 This option provides tracing for the TREE_RCU and
436 TREE_PREEMPT_RCU implementations, permitting Makefile to
437 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800438
Mike Travisc903ff82009-01-15 12:28:29 -0800439endmenu # "RCU Subsystem"
440
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700442 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 ---help---
444 This option enables the complete Linux kernel ".config" file
445 contents to be saved in the kernel. It provides documentation
446 of which kernel options are used in a running kernel or in an
447 on-disk kernel. This information can be extracted from the kernel
448 image file with the script scripts/extract-ikconfig and used as
449 input to rebuild the current kernel or to build another kernel.
450 It can also be extracted from a running kernel by reading
451 /proc/config.gz if enabled (below).
452
453config IKCONFIG_PROC
454 bool "Enable access to .config through /proc/config.gz"
455 depends on IKCONFIG && PROC_FS
456 ---help---
457 This option enables access to the kernel configuration file
458 through /proc/config.gz.
459
Alistair John Strachan794543a2007-05-08 00:31:15 -0700460config LOG_BUF_SHIFT
461 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
462 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700463 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700464 help
465 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700466 Examples:
467 17 => 128 KB
468 16 => 64 KB
469 15 => 32 KB
470 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700471 13 => 8 KB
472 12 => 4 KB
473
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800474#
475# Architectures with an unreliable sched_clock() should select this:
476#
477config HAVE_UNSTABLE_SCHED_CLOCK
478 bool
479
Li Zefan23964d22009-01-15 13:50:58 -0800480menuconfig CGROUPS
481 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800482 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700483 help
Li Zefan23964d22009-01-15 13:50:58 -0800484 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800485 use with process control subsystems such as Cpusets, CFS, memory
486 controls or device isolation.
487 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800488 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800489 - Documentation/cgroups/ (features for grouping, isolation
490 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700491
492 Say N if unsure.
493
Li Zefan23964d22009-01-15 13:50:58 -0800494if CGROUPS
495
Paul Menage006cb992007-10-18 23:39:43 -0700496config CGROUP_DEBUG
497 bool "Example debug cgroup subsystem"
498 depends on CGROUPS
Paul Menage418d7d82008-04-29 01:00:05 -0700499 default n
Paul Menage006cb992007-10-18 23:39:43 -0700500 help
501 This option enables a simple cgroup subsystem that
502 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800503 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700504
Li Zefan23964d22009-01-15 13:50:58 -0800505 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700506
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700507config CGROUP_NS
Li Zefan23964d22009-01-15 13:50:58 -0800508 bool "Namespace cgroup subsystem"
509 depends on CGROUPS
510 help
511 Provides a simple namespace cgroup subsystem to
512 provide hierarchical naming of sets of namespaces,
513 for instance virtual servers and checkpoint/restart
514 jobs.
Serge E. Hallyn858d72e2007-10-18 23:39:45 -0700515
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700516config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800517 bool "Freezer cgroup subsystem"
518 depends on CGROUPS
519 help
520 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700521 cgroup.
522
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700523config CGROUP_DEVICE
524 bool "Device controller for cgroups"
525 depends on CGROUPS && EXPERIMENTAL
526 help
527 Provides a cgroup implementing whitelists for devices which
528 a process in the cgroup can mknod or open.
529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530config CPUSETS
531 bool "Cpuset support"
Paul Menagedb7f47c2009-04-02 16:57:55 -0700532 depends on CGROUPS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700534 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 allow dynamically partitioning a system into sets of CPUs and
536 Memory Nodes and assigning tasks to run only within those sets.
537 This is primarily useful on large SMP or NUMA systems.
538
539 Say N if unsure.
540
Li Zefan23964d22009-01-15 13:50:58 -0800541config PROC_PID_CPUSET
542 bool "Include legacy /proc/<pid>/cpuset file"
543 depends on CPUSETS
544 default y
545
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100546config CGROUP_CPUACCT
547 bool "Simple CPU accounting cgroup subsystem"
548 depends on CGROUPS
549 help
550 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800551 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100552
Pavel Emelianove552b662008-02-07 00:13:49 -0800553config RESOURCE_COUNTERS
554 bool "Resource counters"
555 help
556 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800557 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800558 depends on CGROUPS
559
Balbir Singh00f0b822008-03-04 14:28:39 -0800560config CGROUP_MEM_RES_CTLR
561 bool "Memory Resource Controller for Control Groups"
562 depends on CGROUPS && RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700563 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800564 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700565 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100566 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800567
568 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700569 associated with each page of memory in the system. By this,
570 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
571 usage tracking struct at boot. Total amount of this is printed out
572 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800573
574 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700575 sure you need the memory resource controller. Even when you enable
576 this, you can set "cgroup_disable=memory" at your boot option to
577 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800578 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800579
Balbir Singhcf475ad2008-04-29 01:00:16 -0700580 This config option also selects MM_OWNER config option, which
581 could in turn add some fork/exit overhead.
582
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800583config CGROUP_MEM_RES_CTLR_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700584 bool "Memory Resource Controller Swap Extension"
585 depends on CGROUP_MEM_RES_CTLR && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800586 help
587 Add swap management feature to memory resource controller. When you
588 enable this, you can limit mem+swap usage per cgroup. In other words,
589 when you disable this, memory resource controller has no cares to
590 usage of swap...a process can exhaust all of the swap. This extension
591 is useful when you want to avoid exhaustion swap but this itself
592 adds more overheads and consumes memory for remembering information.
593 Especially if you use 32bit system or small memory system, please
594 be careful about enabling this. When memory resource controller
595 is disabled by boot option, this will be automatically disabled and
596 there will be no overhead from this. Even when you set this config=y,
597 if boot option "noswapaccount" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700598 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
599 size is 4096bytes, 512k per 1Gbytes of swap.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800600
Dhaval Giani7c941432010-01-20 13:26:18 +0100601menuconfig CGROUP_SCHED
602 bool "Group CPU scheduler"
603 depends on EXPERIMENTAL && CGROUPS
604 default n
605 help
606 This feature lets CPU scheduler recognize task groups and control CPU
607 bandwidth allocation to such task groups. It uses cgroups to group
608 tasks.
609
610if CGROUP_SCHED
611config FAIR_GROUP_SCHED
612 bool "Group scheduling for SCHED_OTHER"
613 depends on CGROUP_SCHED
614 default CGROUP_SCHED
615
616config RT_GROUP_SCHED
617 bool "Group scheduling for SCHED_RR/FIFO"
618 depends on EXPERIMENTAL
619 depends on CGROUP_SCHED
620 default n
621 help
622 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800623 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100624 schedule realtime tasks for non-root users until you allocate
625 realtime bandwidth for them.
626 See Documentation/scheduler/sched-rt-group.txt for more information.
627
628endif #CGROUP_SCHED
629
Vivek Goyalafc24d42010-04-26 19:27:56 +0200630config BLK_CGROUP
631 tristate "Block IO controller"
632 depends on CGROUPS && BLOCK
633 default n
634 ---help---
635 Generic block IO controller cgroup interface. This is the common
636 cgroup interface which should be used by various IO controlling
637 policies.
638
639 Currently, CFQ IO scheduler uses it to recognize task groups and
640 control disk bandwidth allocation (proportional time slice allocation)
641 to such task groups.
642
643 This option only enables generic Block IO controller infrastructure.
644 One needs to also enable actual IO controlling logic in CFQ for it
645 to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
646
647 See Documentation/cgroups/blkio-controller.txt for more information.
648
649config DEBUG_BLK_CGROUP
650 bool "Enable Block IO controller debugging"
651 depends on BLK_CGROUP
652 default n
653 ---help---
654 Enable some debugging help. Currently it exports additional stat
655 files in a cgroup which can be useful for debugging.
656
Li Zefan23964d22009-01-15 13:50:58 -0800657endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800658
Li Zefan23964d22009-01-15 13:50:58 -0800659config MM_OWNER
660 bool
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800661
Kay Sievers88a22c92006-09-14 11:23:28 +0200662config SYSFS_DEPRECATED
Ingo Molnard47846c2008-03-04 14:54:47 +0100663 bool
664
665config SYSFS_DEPRECATED_V2
Uwe Kleine-König9e9868a2009-12-03 19:58:00 +0100666 bool "enable deprecated sysfs features to support old userspace tools"
Randy Dunlap9148fe82007-12-31 10:05:34 -0800667 depends on SYSFS
Kay Sieversf6ee6492009-04-16 19:56:37 +0200668 default n
Ingo Molnard47846c2008-03-04 14:54:47 +0100669 select SYSFS_DEPRECATED
Kay Sievers88a22c92006-09-14 11:23:28 +0200670 help
Kay Sieversfce3e802008-11-01 14:03:00 +0100671 This option switches the layout of sysfs to the deprecated
Kay Sieversf6ee6492009-04-16 19:56:37 +0200672 version. Do not use it on recent distributions.
Kay Sievers88a22c92006-09-14 11:23:28 +0200673
Kay Sieversfce3e802008-11-01 14:03:00 +0100674 The current sysfs layout features a unified device tree at
675 /sys/devices/, which is able to express a hierarchy between
676 class devices. If the deprecated option is set to Y, the
677 unified device tree is split into a bus device tree at
678 /sys/devices/ and several individual class device trees at
679 /sys/class/. The class and bus devices will be connected by
680 "<subsystem>:<name>" and the "device" links. The "block"
681 class devices, will not show up in /sys/class/block/. Some
682 subsystems will suppress the creation of some devices which
683 depend on the unified device tree.
Kay Sievers88a22c92006-09-14 11:23:28 +0200684
Kay Sieversfce3e802008-11-01 14:03:00 +0100685 This option is not a pure compatibility option that can
686 be safely enabled on newer distributions. It will change the
687 layout of sysfs to the non-extensible deprecated version,
688 and disable some features, which can not be exported without
689 confusing older userspace tools. Since 2007/2008 all major
690 distributions do not enable this option, and ship no tools which
691 depend on the deprecated layout or this option.
692
693 If you are using a new kernel on an older distribution, or use
694 older userspace tools, you might need to say Y here. Do not say Y,
695 if the original kernel, that came with your distribution, has
696 this option set to N.
Kay Sievers88a22c92006-09-14 11:23:28 +0200697
Jens Axboeb86ff9812006-03-23 19:56:55 +0100698config RELAY
699 bool "Kernel->user space relay support (formerly relayfs)"
700 help
701 This option enables support for relay interface support in
702 certain file systems (such as debugfs).
703 It is designed to provide an efficient mechanism for tools and
704 facilities to relay large amounts of data from kernel space to
705 user space.
706
707 If unsure, say N.
708
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800709config NAMESPACES
710 bool "Namespaces support" if EMBEDDED
711 default !EMBEDDED
712 help
713 Provides the way to make tasks work with different objects using
714 the same id. For example same IPC id may refer to different objects
715 or same user id or pid may refer to different tasks when used in
716 different namespaces.
717
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800718config UTS_NS
719 bool "UTS namespace"
720 depends on NAMESPACES
721 help
722 In this namespace tasks see different info provided with the
723 uname() system call
724
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800725config IPC_NS
726 bool "IPC namespace"
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700727 depends on NAMESPACES && (SYSVIPC || POSIX_MQUEUE)
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800728 help
729 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700730 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800731
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800732config USER_NS
733 bool "User namespace (EXPERIMENTAL)"
734 depends on NAMESPACES && EXPERIMENTAL
735 help
736 This allows containers, i.e. vservers, to use user namespaces
737 to provide different user info for different servers.
738 If unsure, say N.
739
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800740config PID_NS
741 bool "PID Namespaces (EXPERIMENTAL)"
742 default n
743 depends on NAMESPACES && EXPERIMENTAL
744 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300745 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100746 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800747 pid namespaces. This is a building block of containers.
748
749 Unless you want to work with an experimental feature
750 say N here.
751
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800752config NET_NS
753 bool "Network namespace"
754 default n
755 depends on NAMESPACES && EXPERIMENTAL && NET
756 help
757 Allow user space to create what appear to be multiple instances
758 of the network stack.
759
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -0800760config BLK_DEV_INITRD
761 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
762 depends on BROKEN || !FRV
763 help
764 The initial RAM filesystem is a ramfs which is loaded by the
765 boot loader (loadlin or lilo) and that is mounted as root
766 before the normal boot procedure. It is typically used to
767 load modules needed to mount the "real" root file system,
768 etc. See <file:Documentation/initrd.txt> for details.
769
770 If RAM disk support (BLK_DEV_RAM) is also included, this
771 also enables initial RAM disk (initrd) support and adds
772 15 Kbytes (more on some other architectures) to the kernel size.
773
774 If unsure say Y.
775
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800776if BLK_DEV_INITRD
777
Sam Ravnborgdbec4862005-08-10 20:44:50 +0200778source "usr/Kconfig"
779
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -0800780endif
781
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800782config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +0200783 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800784 default y
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800785 help
786 Enabling this option will pass "-Os" instead of "-O2" to gcc
787 resulting in a smaller kernel.
788
jkacur775a7222008-07-16 00:31:16 +0200789 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -0800790
Randy Dunlap08470622006-09-30 23:28:13 -0700791config SYSCTL
792 bool
793
Randy Dunlapb943c462009-03-10 12:55:46 -0700794config ANON_INODES
795 bool
796
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797menuconfig EMBEDDED
798 bool "Configure standard kernel features (for small systems)"
799 help
800 This option allows certain base kernel options and settings
801 to be disabled or tweaked. This is for specialized
802 environments which can tolerate a "non-standard" kernel.
803 Only use this if you really know what you are doing.
804
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700805config UID16
806 bool "Enable 16-bit UID system calls" if EMBEDDED
David S. Miller09337f52008-04-26 03:17:12 -0700807 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 -0700808 default y
809 help
810 This enables the legacy 16-bit UID syscall wrappers.
811
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700812config SYSCTL_SYSCALL
Randy Dunlap08470622006-09-30 23:28:13 -0700813 bool "Sysctl syscall support" if EMBEDDED
Eric W. Biederman26a70342009-11-05 05:26:41 -0800814 depends on PROC_SYSCTL
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800815 default y
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700816 select SYSCTL
817 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800818 sys_sysctl uses binary paths that have been found challenging
819 to properly maintain and use. The interface in /proc/sys
820 using paths with ascii names is now the primary path to this
821 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700822
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800823 Almost nothing using the binary sysctl interface so if you are
824 trying to save some space it is probably safe to disable this,
825 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -0700826
Eric W. Biederman13bb7e32006-11-08 17:44:51 -0800827 If unsure say Y here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -0700828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829config KALLSYMS
Jesper Juhl979c6a12006-12-12 19:25:11 +0100830 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 default y
832 help
833 Say Y here to let the kernel print out symbolic crash information and
834 symbolic stack backtraces. This increases the size of the kernel
835 somewhat, as all symbols have to be loaded into the kernel image.
836
837config KALLSYMS_ALL
838 bool "Include all symbols in kallsyms"
839 depends on DEBUG_KERNEL && KALLSYMS
840 help
841 Normally kallsyms only contains the symbols of functions, for nicer
842 OOPS messages. Some debuggers can use kallsyms for other
Jesper Juhlf9f97bc2005-07-20 05:43:05 +0200843 symbols too: say Y here to include all symbols, if you need them
844 and you don't care about adding 300k to the size of your kernel.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845
846 Say N.
847
848config KALLSYMS_EXTRA_PASS
849 bool "Do an extra kallsyms pass"
850 depends on KALLSYMS
851 help
852 If kallsyms is not working correctly, the build will fail with
853 inconsistent kallsyms data. If that occurs, log a bug report and
854 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
855 Always say N here unless you find a bug in kallsyms, which must be
856 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
857 you wait for kallsyms to be fixed.
858
Matt Mackalld59745c2005-05-01 08:59:02 -0700859
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -0800860config HOTPLUG
861 bool "Support for hot-pluggable devices" if EMBEDDED
862 default y
863 help
864 This option is provided for the case where no hotplug or uevent
865 capabilities is wanted by the kernel. You should only consider
866 disabling this option for embedded systems that do not use modules, a
867 dynamic /dev tree, or dynamic device discovery. Just say Y.
868
Matt Mackalld59745c2005-05-01 08:59:02 -0700869config PRINTK
870 default y
871 bool "Enable support for printk" if EMBEDDED
872 help
873 This option enables normal printk support. Removing it
874 eliminates most of the message strings from the kernel image
875 and makes the kernel more or less silent. As this makes it
876 very difficult to diagnose system problems, saying N here is
877 strongly discouraged.
878
Matt Mackallc8538a72005-05-01 08:59:01 -0700879config BUG
880 bool "BUG() support" if EMBEDDED
881 default y
882 help
883 Disabling this option eliminates support for BUG and WARN, reducing
884 the size of your kernel image and potentially quietly ignoring
885 numerous fatal conditions. You should only consider disabling this
886 option for embedded systems with no facilities for reporting errors.
887 Just say Y.
888
Matt Mackall708e9a72006-01-08 01:05:25 -0800889config ELF_CORE
890 default y
891 bool "Enable ELF core dumps" if EMBEDDED
892 help
893 Enable support for generating core dumps. Disabling saves about 4k.
894
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +0200895config PCSPKR_PLATFORM
896 bool "Enable PC-Speaker support" if EMBEDDED
897 depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
898 default y
899 help
900 This option allows to disable the internal PC-Speaker
901 support, saving some memory.
902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903config BASE_FULL
904 default y
905 bool "Enable full-sized data structures for core" if EMBEDDED
906 help
907 Disabling this option reduces the size of miscellaneous core
908 kernel data structures. This saves memory on small machines,
909 but may reduce performance.
910
911config FUTEX
912 bool "Enable futex support" if EMBEDDED
913 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -0700914 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 help
916 Disabling this option will cause the kernel to be built without
917 support for "fast userspace mutexes". The resulting kernel may not
918 run glibc-based applications correctly.
919
920config EPOLL
921 bool "Enable eventpoll support" if EMBEDDED
922 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700923 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 help
925 Disabling this option will cause the kernel to be built without
926 support for epoll family of system calls.
927
Davide Libenzifba2afa2007-05-10 22:23:13 -0700928config SIGNALFD
929 bool "Enable signalfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700930 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -0700931 default y
932 help
933 Enable the signalfd() system call that allows to receive signals
934 on a file descriptor.
935
936 If unsure, say Y.
937
Davide Libenzib215e282007-05-10 22:23:16 -0700938config TIMERFD
939 bool "Enable timerfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700940 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -0700941 default y
942 help
943 Enable the timerfd() system call that allows to receive timer
944 events on a file descriptor.
945
946 If unsure, say Y.
947
Davide Libenzie1ad7462007-05-10 22:23:19 -0700948config EVENTFD
949 bool "Enable eventfd() system call" if EMBEDDED
Adrian Bunk448e3ce2007-07-31 00:39:10 -0700950 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -0700951 default y
952 help
953 Enable the eventfd() system call that allows to receive both
954 kernel notification (ie. KAIO) or userspace notifications.
955
956 If unsure, say Y.
957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958config SHMEM
959 bool "Use full shmem filesystem" if EMBEDDED
960 default y
961 depends on MMU
962 help
963 The shmem is an internal filesystem used to manage shared memory.
964 It is backed by swap and manages resource limits. It is also exported
965 to userspace as tmpfs if TMPFS is enabled. Disabling this
966 option replaces shmem and tmpfs with the much simpler ramfs code,
967 which may be appropriate on small systems without swap.
968
Thomas Petazzoniebf3f092008-10-15 22:05:12 -0700969config AIO
970 bool "Enable AIO support" if EMBEDDED
971 default y
972 help
973 This option enables POSIX asynchronous I/O which may by used
974 by some high performance threaded applications. Disabling
975 this option saves about 7k.
976
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200977config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +0100978 bool
Mike Frysinger018df722009-06-12 13:17:43 -0400979 help
980 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100981
Peter Zijlstra906010b2009-09-21 16:08:49 +0200982config PERF_USE_VMALLOC
983 bool
984 help
985 See tools/perf/design.txt for details
986
Ingo Molnar57c0c152009-09-21 12:20:38 +0200987menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +0100988
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200989config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +0200990 bool "Kernel performance events and counters"
991 default y if (PROFILING || PERF_COUNTERS)
Ingo Molnarcdd6c482009-09-21 12:02:48 +0200992 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +0100993 select ANON_INODES
Thomas Gleixner0793a612008-12-04 20:12:29 +0100994 help
Ingo Molnar57c0c152009-09-21 12:20:38 +0200995 Enable kernel support for various performance events provided
996 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +0100997
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -0200998 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +0200999 use of generic tracepoints.
1000
1001 Most modern CPUs support performance events via performance
1002 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001003 types of hw events: such as instructions executed, cachemisses
1004 suffered, or branches mis-predicted - without slowing down the
1005 kernel or applications. These registers can also trigger interrupts
1006 when a threshold number of events have passed - and can thus be
1007 used to profile the code that runs on that CPU.
1008
Ingo Molnar57c0c152009-09-21 12:20:38 +02001009 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001010 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001011 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001012 provides per task and per CPU counters, and it provides event
1013 capabilities on top of those.
1014
1015 Say Y if unsure.
1016
Ingo Molnar57c0c152009-09-21 12:20:38 +02001017config PERF_COUNTERS
1018 bool "Kernel performance counters (old config option)"
1019 depends on HAVE_PERF_EVENTS
1020 help
1021 This config has been obsoleted by the PERF_EVENTS
1022 config option - please see that one for details.
1023
1024 It has no effect on the kernel whether you enable
1025 it or not, it is a compatibility placeholder.
1026
1027 Say N if unsure.
1028
Peter Zijlstra906010b2009-09-21 16:08:49 +02001029config DEBUG_PERF_USE_VMALLOC
1030 default n
1031 bool "Debug: use vmalloc to back perf mmap() buffers"
1032 depends on PERF_EVENTS && DEBUG_KERNEL
1033 select PERF_USE_VMALLOC
1034 help
1035 Use vmalloc memory to back perf mmap() buffers.
1036
1037 Mostly useful for debugging the vmalloc code on platforms
1038 that don't require it.
1039
1040 Say N if unsure.
1041
Thomas Gleixner0793a612008-12-04 20:12:29 +01001042endmenu
1043
Christoph Lameterf8891e52006-06-30 01:55:45 -07001044config VM_EVENT_COUNTERS
1045 default y
1046 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
1047 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001048 VM event counters are needed for event counts to be shown.
1049 This option allows the disabling of the VM event counters
1050 on EMBEDDED systems. /proc/vmstat will only show page counts
1051 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001052
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001053config PCI_QUIRKS
1054 default y
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001055 bool "Enable PCI quirk workarounds" if EMBEDDED
1056 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001057 help
1058 This enables workarounds for various PCI chipset
1059 bugs/quirks. Disable this only if your target machine is
1060 unaffected by PCI quirks.
1061
Christoph Lameter41ecc552007-05-09 02:32:44 -07001062config SLUB_DEBUG
1063 default y
1064 bool "Enable SLUB debugging support" if EMBEDDED
Christoph Lameterf6acb632008-04-29 16:16:06 -07001065 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001066 help
1067 SLUB has extensive debug support features. Disabling these can
1068 result in significant savings in code size. This also disables
1069 SLUB sysfs support. /sys/slab will not exist and there will be
1070 no support for cache validation etc.
1071
Randy Dunlapb943c462009-03-10 12:55:46 -07001072config COMPAT_BRK
1073 bool "Disable heap randomization"
1074 default y
1075 help
1076 Randomizing heap placement makes heap exploits harder, but it
1077 also breaks ancient binaries (including anything libc5 based).
1078 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001079 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001080 /proc/sys/kernel/randomize_va_space to 2.
1081
1082 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1083
Christoph Lameter81819f02007-05-06 14:49:36 -07001084choice
1085 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001086 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001087 help
1088 This option allows to select a slab allocator.
1089
1090config SLAB
1091 bool "SLAB"
1092 help
1093 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001094 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001095 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001096
1097config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001098 bool "SLUB (Unqueued Allocator)"
1099 help
1100 SLUB is a slab allocator that minimizes cache line usage
1101 instead of managing queues of cached objects (SLAB approach).
1102 Per cpu caching is realized using slabs of objects instead
1103 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001104 and has enhanced diagnostics. SLUB is the default choice for
1105 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001106
1107config SLOB
Paul Mundt84a01c22007-07-15 23:38:24 -07001108 depends on EMBEDDED
Christoph Lameter81819f02007-05-06 14:49:36 -07001109 bool "SLOB (Simple Allocator)"
1110 help
Matt Mackall37291452008-02-04 22:29:38 -08001111 SLOB replaces the stock allocator with a drastically simpler
1112 allocator. SLOB is generally more space efficient but
1113 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001114
1115endchoice
1116
Jie Zhangea637632009-12-14 18:00:02 -08001117config MMAP_ALLOW_UNINITIALIZED
1118 bool "Allow mmapped anonymous memory to be uninitialized"
1119 depends on EMBEDDED && !MMU
1120 default n
1121 help
1122 Normally, and according to the Linux spec, anonymous memory obtained
1123 from mmap() has it's contents cleared before it is passed to
1124 userspace. Enabling this config option allows you to request that
1125 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1126 providing a huge performance boost. If this option is not enabled,
1127 then the flag will be ignored.
1128
1129 This is taken advantage of by uClibc's malloc(), and also by
1130 ELF-FDPIC binfmt's brk and stack allocator.
1131
1132 Because of the obvious security issues, this option should only be
1133 enabled on embedded devices where you control what is run in
1134 userspace. Since that isn't generally a problem on no-MMU systems,
1135 it is normally safe to say Y here.
1136
1137 See Documentation/nommu-mmap.txt for more information.
1138
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001139config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001140 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001141 help
1142 Say Y here to enable the extended profiling support mechanisms used
1143 by profilers such as OProfile.
1144
Ingo Molnar5f87f112008-07-23 14:15:22 +02001145#
1146# Place an empty function call at each tracepoint site. Can be
1147# dynamically changed for a probe function.
1148#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001149config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001150 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001151
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001152source "arch/Kconfig"
1153
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154endmenu # General setup
1155
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001156config HAVE_GENERIC_DMA_COHERENT
1157 bool
1158 default n
1159
Linus Torvalds158a9622008-01-02 13:04:48 -08001160config SLABINFO
1161 bool
1162 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001163 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001164 default y
1165
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001166config RT_MUTEXES
1167 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001168
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169config BASE_SMALL
1170 int
1171 default 0 if BASE_FULL
1172 default 1 if !BASE_FULL
1173
Jan Engelhardt66da5732007-07-15 23:39:29 -07001174menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 bool "Enable loadable module support"
1176 help
1177 Kernel modules are small pieces of compiled code which can
1178 be inserted in the running kernel, rather than being
1179 permanently built into the kernel. You use the "modprobe"
1180 tool to add (and sometimes remove) them. If you say Y here,
1181 many parts of the kernel can be built as modules (by
1182 answering M instead of Y where indicated): this is most
1183 useful for infrequently used options which are not required
1184 for booting. For more information, see the man pages for
1185 modprobe, lsmod, modinfo, insmod and rmmod.
1186
1187 If you say Y here, you will need to run "make
1188 modules_install" to put the modules under /lib/modules/
1189 where modprobe can find them (you may need to be root to do
1190 this).
1191
1192 If unsure, say Y.
1193
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001194if MODULES
1195
Linus Torvalds826e4502008-05-04 17:04:16 -07001196config MODULE_FORCE_LOAD
1197 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001198 default n
1199 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001200 Allow loading of modules without version information (ie. modprobe
1201 --force). Forced module loading sets the 'F' (forced) taint flag and
1202 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001203
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204config MODULE_UNLOAD
1205 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 help
1207 Without this option you will not be able to unload any
1208 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001209 anyway), which makes your kernel smaller, faster
1210 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211
1212config MODULE_FORCE_UNLOAD
1213 bool "Forced module unloading"
1214 depends on MODULE_UNLOAD && EXPERIMENTAL
1215 help
1216 This option allows you to force a module to unload, even if the
1217 kernel believes it is unsafe: the kernel will remove the module
1218 without waiting for anyone to stop using it (using the -f option to
1219 rmmod). This is mainly for kernel developers and desperate users.
1220 If unsure, say N.
1221
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001223 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 help
1225 Usually, you have to use modules compiled with your kernel.
1226 Saying Y here makes it sometimes possible to use modules
1227 compiled for different kernels, by adding enough information
1228 to the modules to (hopefully) spot any changes which would
1229 make them incompatible with the kernel you are running. If
1230 unsure, say N.
1231
1232config MODULE_SRCVERSION_ALL
1233 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 help
1235 Modules which contain a MODULE_VERSION get an extra "srcversion"
1236 field inserted into their modinfo section, which contains a
1237 sum of the source files which made it. This helps maintainers
1238 see exactly which source was used to build a module (since
1239 others sometimes change the module source without updating
1240 the version). With this option, such a "srcversion" field
1241 will be created for all modules. If unsure, say N.
1242
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001243endif # MODULES
1244
Rusty Russell98a79d62008-12-13 21:19:41 +10301245config INIT_ALL_POSSIBLE
1246 bool
1247 help
1248 Back when each arch used to define their own cpu_online_map and
1249 cpu_possible_map, some of them chose to initialize cpu_possible_map
1250 with all 1s, and others with all 0s. When they were centralised,
1251 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001252 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301253
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254config STOP_MACHINE
1255 bool
1256 default y
1257 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1258 help
1259 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001260
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001261source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001262
1263config PREEMPT_NOTIFIERS
1264 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001265
Steffen Klassert16295be2010-01-06 19:47:10 +11001266config PADATA
1267 depends on SMP
1268 bool
1269
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001270source "kernel/Kconfig.locks"