blob: c40d0fb044ef373518fc244b6cb6d0c975e64262 [file] [log] [blame]
Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070022
Peter Zijlstrae360adb2010-10-14 14:01:34 +080023config HAVE_IRQ_WORK
24 bool
25
26config IRQ_WORK
27 bool
28 depends on HAVE_IRQ_WORK
29
David Daney1dbdc6f2012-04-19 14:59:57 -070030config BUILDTIME_EXTABLE_SORT
31 bool
32
Al Boldiff0cfc62007-07-31 00:39:23 -070033menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35config EXPERIMENTAL
36 bool "Prompt for development and/or incomplete code/drivers"
37 ---help---
38 Some of the various things that Linux supports (such as network
39 drivers, file systems, network protocols, etc.) can be in a state
40 of development where the functionality, stability, or the level of
41 testing is not yet high enough for general use. This is usually
42 known as the "alpha-test" phase among developers. If a feature is
43 currently in alpha-test, then the developers usually discourage
44 uninformed widespread use of this feature by the general public to
45 avoid "Why doesn't this work?" type mail messages. However, active
46 testing and use of these systems is welcomed. Just be aware that it
47 may not meet the normal level of reliability or it may fail to work
48 in some special cases. Detailed bug reports from people familiar
49 with the kernel internals are usually welcomed by the developers
50 (before submitting bug reports, please read the documents
51 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
52 <file:Documentation/BUG-HUNTING>, and
53 <file:Documentation/oops-tracing.txt> in the kernel source).
54
55 This option will also make obsoleted drivers available. These are
56 drivers that have been replaced by something else, and/or are
57 scheduled to be removed in a future kernel release.
58
59 Unless you intend to help test and develop a feature or driver that
60 falls into this category, or you have a situation that requires
61 using these features, you should probably say N here, which will
62 cause the configurator to present you with fewer choices. If
63 you say Y here, you will be offered the choice of using features or
64 drivers that are currently considered to be in the alpha-test phase.
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066config BROKEN
67 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69config BROKEN_ON_SMP
70 bool
71 depends on BROKEN || !SMP
72 default y
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074config INIT_ENV_ARG_LIMIT
75 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070076 default 32 if !UML
77 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080079 Maximum of each of the number of arguments and environment
80 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Roland McGrath84336462009-12-21 16:24:06 -080083config CROSS_COMPILE
84 string "Cross-compiler tool prefix"
85 help
86 Same as running 'make CROSS_COMPILE=prefix-' but stored for
87 default make runs in this kernel build directory. You don't
88 need to set this unless you want the configured kernel build
89 directory to select the cross-compiler automatically.
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091config LOCALVERSION
92 string "Local version - append to kernel release"
93 help
94 Append an extra string to the end of your kernel version.
95 This will show up when you type uname, for example.
96 The string you set here will be appended after the contents of
97 any files with a filename matching localversion* in your
98 object and source tree, in that order. Your total string can
99 be a maximum of 64 characters.
100
Ryan Andersonaaebf432005-07-31 04:57:49 -0400101config LOCALVERSION_AUTO
102 bool "Automatically append version information to the version string"
103 default y
104 help
105 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 release tree by looking for git tags that belong to the current
107 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400108
109 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400111 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200112 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400113
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200114 (The actual string used here is the first eight characters produced
115 by running the command:
116
117 $ git rev-parse --verify HEAD
118
119 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400120
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800121config HAVE_KERNEL_GZIP
122 bool
123
124config HAVE_KERNEL_BZIP2
125 bool
126
127config HAVE_KERNEL_LZMA
128 bool
129
Lasse Collin3ebe1242011-01-12 17:01:23 -0800130config HAVE_KERNEL_XZ
131 bool
132
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800133config HAVE_KERNEL_LZO
134 bool
135
Alain Knaff30d65db2009-01-04 22:46:17 +0100136choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800137 prompt "Kernel compression mode"
138 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800139 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800140 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100141 The linux kernel is a kind of self-extracting executable.
142 Several compression algorithms are available, which differ
143 in efficiency, compression and decompression speed.
144 Compression speed is only relevant when building a kernel.
145 Decompression speed is relevant at each boot.
146
147 If you have any problems with bzip2 or lzma compressed
148 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
149 version of this functionality (bzip2 only), for 2.4, was
150 supplied by Christian Ludwig)
151
152 High compression options are mostly useful for users, who
153 are low on disk space (embedded systems), but for whom ram
154 size matters less.
155
156 If in doubt, select 'gzip'
157
158config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800159 bool "Gzip"
160 depends on HAVE_KERNEL_GZIP
161 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800162 The old and tried gzip compression. It provides a good balance
163 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100164
165config KERNEL_BZIP2
166 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100168 help
169 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700170 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800171 size is about 10% smaller with bzip2, in comparison to gzip.
172 Bzip2 uses a large amount of memory. For modern kernels you
173 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100174
175config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800176 bool "LZMA"
177 depends on HAVE_KERNEL_LZMA
178 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700179 This compression algorithm's ratio is best. Decompression speed
180 is between gzip and bzip2. Compression is slowest.
181 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100182
Lasse Collin3ebe1242011-01-12 17:01:23 -0800183config KERNEL_XZ
184 bool "XZ"
185 depends on HAVE_KERNEL_XZ
186 help
187 XZ uses the LZMA2 algorithm and instruction set specific
188 BCJ filters which can improve compression ratio of executable
189 code. The size of the kernel is about 30% smaller with XZ in
190 comparison to gzip. On architectures for which there is a BCJ
191 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
192 will create a few percent smaller kernel than plain LZMA.
193
194 The speed is about the same as with LZMA: The decompression
195 speed of XZ is better than that of bzip2 but worse than gzip
196 and LZO. Compression is slow.
197
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800198config KERNEL_LZO
199 bool "LZO"
200 depends on HAVE_KERNEL_LZO
201 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700202 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200203 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800204 (both compression and decompression) is the fastest.
205
Alain Knaff30d65db2009-01-04 22:46:17 +0100206endchoice
207
Josh Triplettbd5dc172011-06-15 15:08:28 -0700208config DEFAULT_HOSTNAME
209 string "Default hostname"
210 default "(none)"
211 help
212 This option determines the default system hostname before userspace
213 calls sethostname(2). The kernel traditionally uses "(none)" here,
214 but you may wish to use a different default here to make a minimal
215 system more usable with less configuration.
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217config SWAP
218 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200219 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 default y
221 help
222 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100223 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 used to provide more virtual memory than the actual RAM present
225 in your computer. If unsure say Y.
226
227config SYSVIPC
228 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 ---help---
230 Inter Process Communication is a suite of library functions and
231 system calls which let processes (running programs) synchronize and
232 exchange information. It is generally considered to be a good thing,
233 and some programs won't run unless you say Y here. In particular, if
234 you want to run the DOS emulator dosemu under Linux (read the
235 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
236 you'll need to say Y here.
237
238 You can find documentation about IPC with "info ipc" and also in
239 section 6.4 of the Linux Programmer's Guide, available from
240 <http://www.tldp.org/guides.html>.
241
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800242config SYSVIPC_SYSCTL
243 bool
244 depends on SYSVIPC
245 depends on SYSCTL
246 default y
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248config POSIX_MQUEUE
249 bool "POSIX Message Queues"
250 depends on NET && EXPERIMENTAL
251 ---help---
252 POSIX variant of message queues is a part of IPC. In POSIX message
253 queues every message has a priority which decides about succession
254 of receiving it by a process. If you want to compile and run
255 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200256 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 POSIX message queues are visible as a filesystem called 'mqueue'
259 and can be mounted somewhere if you want to do filesystem
260 operations on message queues.
261
262 If unsure, say Y.
263
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700264config POSIX_MQUEUE_SYSCTL
265 bool
266 depends on POSIX_MQUEUE
267 depends on SYSCTL
268 default y
269
Frederic Weisbeckerb9527412012-06-16 15:39:34 +0200270config VIRT_CPU_ACCOUNTING
271 bool "Deterministic task and CPU time accounting"
272 depends on HAVE_VIRT_CPU_ACCOUNTING
273 default y if PPC64
274 help
275 Select this option to enable more accurate task and CPU time
276 accounting. This is done by reading a CPU counter on each
277 kernel entry and exit and on transitions within the kernel
278 between system, softirq and hardirq state, so there is a
279 small performance impact. In the case of s390 or IBM POWER > 5,
280 this also enables accounting of stolen time on logically-partitioned
281 systems.
282
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283config BSD_PROCESS_ACCT
284 bool "BSD Process Accounting"
285 help
286 If you say Y here, a user level program will be able to instruct the
287 kernel (via a special system call) to write process accounting
288 information to a file: whenever a process exits, information about
289 that process will be appended to the file by the kernel. The
290 information includes things such as creation time, owning user,
291 command name, memory usage, controlling terminal etc. (the complete
292 list is in the struct acct in <file:include/linux/acct.h>). It is
293 up to the user level program to do useful things with this
294 information. This is generally a good idea, so say Y.
295
296config BSD_PROCESS_ACCT_V3
297 bool "BSD Process Accounting version 3 file format"
298 depends on BSD_PROCESS_ACCT
299 default n
300 help
301 If you say Y here, the process accounting information is written
302 in a new file format that also logs the process IDs of each
303 process and it's parent. Note that this file format is incompatible
304 with previous v0/v1/v2 file formats, so you will need updated tools
305 for processing it. A preliminary version of these tools is available
S.Çağlar Onur37a4c942008-06-18 11:45:13 +0300306 at <http://www.gnu.org/software/acct/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530308config FHANDLE
309 bool "open by fhandle syscalls"
310 select EXPORTFS
311 help
312 If you say Y here, a user level program will be able to map
313 file names to handle and then later use the handle for
314 different file system operations. This is useful in implementing
315 userspace file servers, which now track files using handles instead
316 of names. The handle would remain the same even if file names
317 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
318 syscalls.
319
Shailabh Nagarc7572492006-07-14 00:24:40 -0700320config TASKSTATS
321 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
322 depends on NET
323 default n
324 help
325 Export selected statistics for tasks/processes through the
326 generic netlink interface. Unlike BSD process accounting, the
327 statistics are available during the lifetime of tasks/processes as
328 responses to commands. Like BSD accounting, they are sent to user
329 space on task exit.
330
331 Say N if unsure.
332
Shailabh Nagarca74e922006-07-14 00:24:36 -0700333config TASK_DELAY_ACCT
334 bool "Enable per-task delay accounting (EXPERIMENTAL)"
Shailabh Nagar6f449932006-07-14 00:24:41 -0700335 depends on TASKSTATS
Shailabh Nagarca74e922006-07-14 00:24:36 -0700336 help
337 Collect information on time spent by a task waiting for system
338 resources like cpu, synchronous block I/O completion and swapping
339 in pages. Such statistics can help in setting a task's priorities
340 relative to other tasks for cpu, io, rss limits etc.
341
342 Say N if unsure.
343
Alexey Dobriyan18f705f2007-02-10 01:46:44 -0800344config TASK_XACCT
345 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
346 depends on TASKSTATS
347 help
348 Collect extended task accounting data and send the data
349 to userland for processing over the taskstats interface.
350
351 Say N if unsure.
352
353config TASK_IO_ACCOUNTING
354 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
355 depends on TASK_XACCT
356 help
357 Collect information on the number of bytes of storage I/O which this
358 task has caused.
359
360 Say N if unsure.
361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362config AUDIT
363 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100364 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 help
366 Enable auditing infrastructure that can be used with another
367 kernel subsystem, such as SELinux (which requires this for
368 logging of avc messages output). Does not do system-call
369 auditing without CONFIG_AUDITSYSCALL.
370
371config AUDITSYSCALL
372 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100373 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 default y if SECURITY_SELINUX
375 help
376 Enable low-overhead system-call auditing infrastructure that
377 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500378 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
Eric Paris939a67f2009-12-17 20:12:06 -0500380config AUDIT_WATCH
381 def_bool y
382 depends on AUDITSYSCALL
383 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
Al Viro74c3cbe2007-07-22 08:04:18 -0400385config AUDIT_TREE
386 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400387 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500388 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400389
Eric Paris633b4542012-01-03 14:23:08 -0500390config AUDIT_LOGINUID_IMMUTABLE
391 bool "Make audit loginuid immutable"
392 depends on AUDIT
393 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800394 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500395 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
396 but should instead only allow setting its loginuid if it was never
397 previously set. On systems which use systemd or a similar central
398 process to restart login services this should be set to true. On older
399 systems in which an admin would typically have to directly stop and
400 start processes this should be set to false. Setting this to true allows
401 one to drop potentially dangerous capabilites from the login tasks,
402 but may not be backwards compatible with older init systems.
403
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000404source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200405source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000406
Mike Travisc903ff82009-01-15 12:28:29 -0800407menu "RCU Subsystem"
408
409choice
410 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700411 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800412
Mike Travisc903ff82009-01-15 12:28:29 -0800413config TREE_RCU
414 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700415 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800416 help
417 This option selects the RCU implementation that is
418 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700419 thousands of CPUs. It also scales down nicely to
420 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800421
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700422config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700423 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700424 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700425 help
426 This option selects the RCU implementation that is
427 designed for very large SMP systems with hundreds or
428 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700429 is also required. It also scales down nicely to
430 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700431
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700432config TINY_RCU
433 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700434 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700435 help
436 This option selects the RCU implementation that is
437 designed for UP systems from which real-time response
438 is not required. This option greatly reduces the
439 memory footprint of RCU.
440
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700441config TINY_PREEMPT_RCU
442 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700443 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700444 help
445 This option selects the RCU implementation that is designed
446 for real-time UP systems. This option greatly reduces the
447 memory footprint of RCU.
448
Mike Travisc903ff82009-01-15 12:28:29 -0800449endchoice
450
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700451config PREEMPT_RCU
452 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
453 help
454 This option enables preemptible-RCU code that is common between
455 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
456
Mike Travisc903ff82009-01-15 12:28:29 -0800457config RCU_FANOUT
458 int "Tree-based hierarchical RCU fanout value"
459 range 2 64 if 64BIT
460 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700461 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800462 default 64 if 64BIT
463 default 32 if !64BIT
464 help
465 This option controls the fanout of hierarchical implementations
466 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700467 large numbers of CPUs. This value must be at least the fourth
468 root of NR_CPUS, which allows NR_CPUS to be insanely large.
469 The default value of RCU_FANOUT should be used for production
470 systems, but if you are stress-testing the RCU implementation
471 itself, small RCU_FANOUT values allow you to test large-system
472 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800473
474 Select a specific number if testing RCU itself.
475 Take the default if unsure.
476
Paul E. McKenney8932a632012-04-19 12:20:14 -0700477config RCU_FANOUT_LEAF
478 int "Tree-based hierarchical RCU leaf-level fanout value"
479 range 2 RCU_FANOUT if 64BIT
480 range 2 RCU_FANOUT if !64BIT
481 depends on TREE_RCU || TREE_PREEMPT_RCU
482 default 16
483 help
484 This option controls the leaf-level fanout of hierarchical
485 implementations of RCU, and allows trading off cache misses
486 against lock contention. Systems that synchronize their
487 scheduling-clock interrupts for energy-efficiency reasons will
488 want the default because the smaller leaf-level fanout keeps
489 lock contention levels acceptably low. Very large systems
490 (hundreds or thousands of CPUs) will instead want to set this
491 value to the maximum value possible in order to reduce the
492 number of cache misses incurred during RCU's grace-period
493 initialization. These systems tend to run CPU-bound, and thus
494 are not helped by synchronized interrupts, and thus tend to
495 skew them, which reduces lock contention enough that large
496 leaf-level fanouts work well.
497
498 Select a specific number if testing RCU itself.
499
500 Select the maximum permissible value for large systems.
501
502 Take the default if unsure.
503
Mike Travisc903ff82009-01-15 12:28:29 -0800504config RCU_FANOUT_EXACT
505 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700506 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800507 default n
508 help
509 This option forces use of the exact RCU_FANOUT value specified,
510 regardless of imbalances in the hierarchy. This is useful for
511 testing RCU itself, and might one day be useful on systems with
512 strong NUMA behavior.
513
514 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
515
516 Say N if unsure.
517
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800518config RCU_FAST_NO_HZ
519 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700520 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800521 default n
522 help
523 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700524 in order to allow CPUs to enter dynticks-idle state more
525 quickly. On the other hand, this option increases the overhead
526 of the dynticks-idle checking, particularly on systems with
527 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800528
529 Say Y if energy efficiency is critically important, particularly
530 if you have relatively few CPUs.
531
532 Say N if you are unsure.
533
Mike Travisc903ff82009-01-15 12:28:29 -0800534config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700535 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800536 select DEBUG_FS
537 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700538 This option provides tracing for the TREE_RCU and
539 TREE_PREEMPT_RCU implementations, permitting Makefile to
540 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800541
Paul E. McKenney24278d12010-09-27 17:25:23 -0700542config RCU_BOOST
543 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800544 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700545 default n
546 help
547 This option boosts the priority of preempted RCU readers that
548 block the current preemptible RCU grace period for too long.
549 This option also prevents heavy loads from blocking RCU
550 callback invocation for all flavors of RCU.
551
552 Say Y here if you are working with real-time apps or heavy loads
553 Say N here if you are unsure.
554
555config RCU_BOOST_PRIO
556 int "Real-time priority to boost RCU readers to"
557 range 1 99
558 depends on RCU_BOOST
559 default 1
560 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700561 This option specifies the real-time priority to which long-term
562 preempted RCU readers are to be boosted. If you are working
563 with a real-time application that has one or more CPU-bound
564 threads running at a real-time priority level, you should set
565 RCU_BOOST_PRIO to a priority higher then the highest-priority
566 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
567 of 1 is appropriate in the common case, which is real-time
568 applications that do not have any CPU-bound threads.
569
570 Some real-time applications might not have a single real-time
571 thread that saturates a given CPU, but instead might have
572 multiple real-time threads that, taken together, fully utilize
573 that CPU. In this case, you should set RCU_BOOST_PRIO to
574 a priority higher than the lowest-priority thread that is
575 conspiring to prevent the CPU from running any non-real-time
576 tasks. For example, if one thread at priority 10 and another
577 thread at priority 5 are between themselves fully consuming
578 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
579 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700580
581 Specify the real-time priority, or take the default if unsure.
582
583config RCU_BOOST_DELAY
584 int "Milliseconds to delay boosting after RCU grace-period start"
585 range 0 3000
586 depends on RCU_BOOST
587 default 500
588 help
589 This option specifies the time to wait after the beginning of
590 a given grace period before priority-boosting preempted RCU
591 readers blocking that grace period. Note that any RCU reader
592 blocking an expedited RCU grace period is boosted immediately.
593
594 Accept the default if unsure.
595
Mike Travisc903ff82009-01-15 12:28:29 -0800596endmenu # "RCU Subsystem"
597
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700599 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 ---help---
601 This option enables the complete Linux kernel ".config" file
602 contents to be saved in the kernel. It provides documentation
603 of which kernel options are used in a running kernel or in an
604 on-disk kernel. This information can be extracted from the kernel
605 image file with the script scripts/extract-ikconfig and used as
606 input to rebuild the current kernel or to build another kernel.
607 It can also be extracted from a running kernel by reading
608 /proc/config.gz if enabled (below).
609
610config IKCONFIG_PROC
611 bool "Enable access to .config through /proc/config.gz"
612 depends on IKCONFIG && PROC_FS
613 ---help---
614 This option enables access to the kernel configuration file
615 through /proc/config.gz.
616
Alistair John Strachan794543a2007-05-08 00:31:15 -0700617config LOG_BUF_SHIFT
618 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
619 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700620 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700621 help
622 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700623 Examples:
624 17 => 128 KB
625 16 => 64 KB
626 15 => 32 KB
627 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700628 13 => 8 KB
629 12 => 4 KB
630
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800631#
632# Architectures with an unreliable sched_clock() should select this:
633#
634config HAVE_UNSTABLE_SCHED_CLOCK
635 bool
636
Li Zefan23964d22009-01-15 13:50:58 -0800637menuconfig CGROUPS
638 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800639 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700640 help
Li Zefan23964d22009-01-15 13:50:58 -0800641 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800642 use with process control subsystems such as Cpusets, CFS, memory
643 controls or device isolation.
644 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800645 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800646 - Documentation/cgroups/ (features for grouping, isolation
647 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700648
649 Say N if unsure.
650
Li Zefan23964d22009-01-15 13:50:58 -0800651if CGROUPS
652
Paul Menage006cb992007-10-18 23:39:43 -0700653config CGROUP_DEBUG
654 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700655 default n
Paul Menage006cb992007-10-18 23:39:43 -0700656 help
657 This option enables a simple cgroup subsystem that
658 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800659 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700660
Li Zefan23964d22009-01-15 13:50:58 -0800661 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700662
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700663config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800664 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800665 help
666 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700667 cgroup.
668
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700669config CGROUP_DEVICE
670 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700671 help
672 Provides a cgroup implementing whitelists for devices which
673 a process in the cgroup can mknod or open.
674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675config CPUSETS
676 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700678 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 allow dynamically partitioning a system into sets of CPUs and
680 Memory Nodes and assigning tasks to run only within those sets.
681 This is primarily useful on large SMP or NUMA systems.
682
683 Say N if unsure.
684
Li Zefan23964d22009-01-15 13:50:58 -0800685config PROC_PID_CPUSET
686 bool "Include legacy /proc/<pid>/cpuset file"
687 depends on CPUSETS
688 default y
689
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100690config CGROUP_CPUACCT
691 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100692 help
693 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800694 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100695
Pavel Emelianove552b662008-02-07 00:13:49 -0800696config RESOURCE_COUNTERS
697 bool "Resource counters"
698 help
699 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800700 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800701
Andrew Mortonc255a452012-07-31 16:43:02 -0700702config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800703 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700704 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700705 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800706 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700707 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100708 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800709
710 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700711 associated with each page of memory in the system. By this,
712 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
713 usage tracking struct at boot. Total amount of this is printed out
714 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800715
716 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700717 sure you need the memory resource controller. Even when you enable
718 this, you can set "cgroup_disable=memory" at your boot option to
719 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800720 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800721
Balbir Singhcf475ad2008-04-29 01:00:16 -0700722 This config option also selects MM_OWNER config option, which
723 could in turn add some fork/exit overhead.
724
Andrew Mortonc255a452012-07-31 16:43:02 -0700725config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700726 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700727 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800728 help
729 Add swap management feature to memory resource controller. When you
730 enable this, you can limit mem+swap usage per cgroup. In other words,
731 when you disable this, memory resource controller has no cares to
732 usage of swap...a process can exhaust all of the swap. This extension
733 is useful when you want to avoid exhaustion swap but this itself
734 adds more overheads and consumes memory for remembering information.
735 Especially if you use 32bit system or small memory system, please
736 be careful about enabling this. When memory resource controller
737 is disabled by boot option, this will be automatically disabled and
738 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700739 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700740 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
741 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700742config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800743 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700744 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800745 default y
746 help
747 Memory Resource Controller Swap Extension comes with its price in
748 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700749 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800750 and let the user enable it by swapaccount boot command line
751 parameter should have this option unselected.
752 For those who want to have the feature enabled by default should
753 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700754 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700755config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000756 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700757 depends on MEMCG && EXPERIMENTAL
Glauber Costae5671df2011-12-11 21:47:01 +0000758 default n
759 help
760 The Kernel Memory extension for Memory Resource Controller can limit
761 the amount of memory used by kernel objects in the system. Those are
762 fundamentally different from the entities handled by the standard
763 Memory Controller, which are page-based, and can be swapped. Users of
764 the kmem extension can use it to guarantee that no group of processes
765 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800766
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700767config CGROUP_HUGETLB
768 bool "HugeTLB Resource Controller for Control Groups"
769 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
770 default n
771 help
772 Provides a cgroup Resource Controller for HugeTLB pages.
773 When you enable this, you can put a per cgroup limit on HugeTLB usage.
774 The limit is enforced during page fault. Since HugeTLB doesn't
775 support page reclaim, enforcing the limit at page fault time implies
776 that, the application will get SIGBUS signal if it tries to access
777 HugeTLB pages beyond its limit. This requires the application to know
778 beforehand how much HugeTLB pages it would require for its use. The
779 control group is tracked in the third page lru pointer. This means
780 that we cannot use the controller with huge page less than 3 pages.
781
Stephane Eraniane5d13672011-02-14 11:20:01 +0200782config CGROUP_PERF
783 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
784 depends on PERF_EVENTS && CGROUPS
785 help
786 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800787 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200788 designated cpu.
789
790 Say N if unsure.
791
Dhaval Giani7c941432010-01-20 13:26:18 +0100792menuconfig CGROUP_SCHED
793 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100794 default n
795 help
796 This feature lets CPU scheduler recognize task groups and control CPU
797 bandwidth allocation to such task groups. It uses cgroups to group
798 tasks.
799
800if CGROUP_SCHED
801config FAIR_GROUP_SCHED
802 bool "Group scheduling for SCHED_OTHER"
803 depends on CGROUP_SCHED
804 default CGROUP_SCHED
805
Paul Turnerab84d312011-07-21 09:43:28 -0700806config CFS_BANDWIDTH
807 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
808 depends on EXPERIMENTAL
809 depends on FAIR_GROUP_SCHED
810 default n
811 help
812 This option allows users to define CPU bandwidth rates (limits) for
813 tasks running within the fair group scheduler. Groups with no limit
814 set are considered to be unconstrained and will run with no
815 restriction.
816 See tip/Documentation/scheduler/sched-bwc.txt for more information.
817
Dhaval Giani7c941432010-01-20 13:26:18 +0100818config RT_GROUP_SCHED
819 bool "Group scheduling for SCHED_RR/FIFO"
820 depends on EXPERIMENTAL
821 depends on CGROUP_SCHED
822 default n
823 help
824 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800825 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100826 schedule realtime tasks for non-root users until you allocate
827 realtime bandwidth for them.
828 See Documentation/scheduler/sched-rt-group.txt for more information.
829
830endif #CGROUP_SCHED
831
Vivek Goyalafc24d42010-04-26 19:27:56 +0200832config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800833 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700834 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200835 default n
836 ---help---
837 Generic block IO controller cgroup interface. This is the common
838 cgroup interface which should be used by various IO controlling
839 policies.
840
841 Currently, CFQ IO scheduler uses it to recognize task groups and
842 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400843 to such task groups. It is also used by bio throttling logic in
844 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200845
846 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400847 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000848 enabling proportional weight division of disk bandwidth in CFQ, set
849 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000850 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200851
852 See Documentation/cgroups/blkio-controller.txt for more information.
853
854config DEBUG_BLK_CGROUP
855 bool "Enable Block IO controller debugging"
856 depends on BLK_CGROUP
857 default n
858 ---help---
859 Enable some debugging help. Currently it exports additional stat
860 files in a cgroup which can be useful for debugging.
861
Li Zefan23964d22009-01-15 13:50:58 -0800862endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800863
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800864config CHECKPOINT_RESTORE
865 bool "Checkpoint/restore support" if EXPERT
866 default n
867 help
868 Enables additional kernel features in a sake of checkpoint/restore.
869 In particular it adds auxiliary prctl codes to setup process text,
870 data and heap segment sizes, and a few additional /proc filesystem
871 entries.
872
873 If unsure, say N here.
874
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700875menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800876 bool "Namespaces support" if EXPERT
877 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800878 help
879 Provides the way to make tasks work with different objects using
880 the same id. For example same IPC id may refer to different objects
881 or same user id or pid may refer to different tasks when used in
882 different namespaces.
883
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700884if NAMESPACES
885
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800886config UTS_NS
887 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700888 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800889 help
890 In this namespace tasks see different info provided with the
891 uname() system call
892
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800893config IPC_NS
894 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700895 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700896 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800897 help
898 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700899 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800900
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800901config USER_NS
902 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700903 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700904 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -0800905 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700906
Eric W. Biederman5673a942011-11-17 10:23:55 -0800907 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800908 help
909 This allows containers, i.e. vservers, to use user namespaces
910 to provide different user info for different servers.
911 If unsure, say N.
912
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800913config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700914 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700915 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800916 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300917 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100918 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800919 pid namespaces. This is a building block of containers.
920
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800921config NET_NS
922 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700923 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700924 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800925 help
926 Allow user space to create what appear to be multiple instances
927 of the network stack.
928
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700929endif # NAMESPACES
930
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700931config UIDGID_CONVERTED
932 # True if all of the selected software conmponents are known
933 # to have uid_t and gid_t converted to kuid_t and kgid_t
934 # where appropriate and are otherwise safe to use with
935 # the user namespace.
936 bool
937 default y
938
939 # List of kernel pieces that need user namespace work
940 # Features
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700941 depends on SYSVIPC = n
942 depends on IMA = n
943 depends on EVM = n
944 depends on KEYS = n
945 depends on AUDIT = n
946 depends on AUDITSYSCALL = n
947 depends on TASKSTATS = n
948 depends on TRACING = n
949 depends on FS_POSIX_ACL = n
950 depends on QUOTA = n
951 depends on QUOTACTL = n
952 depends on DEBUG_CREDENTIALS = n
953 depends on BSD_PROCESS_ACCT = n
954 depends on DRM = n
955 depends on PROC_EVENTS = n
956
957 # Networking
958 depends on NET = n
959 depends on NET_9P = n
960 depends on IPX = n
961 depends on PHONET = n
962 depends on NET_CLS_FLOW = n
963 depends on NETFILTER_XT_MATCH_OWNER = n
964 depends on NETFILTER_XT_MATCH_RECENT = n
965 depends on NETFILTER_XT_TARGET_LOG = n
966 depends on NETFILTER_NETLINK_LOG = n
967 depends on INET = n
968 depends on IPV6 = n
969 depends on IP_SCTP = n
970 depends on AF_RXRPC = n
971 depends on LLC2 = n
972 depends on NET_KEY = n
973 depends on INET_DIAG = n
974 depends on DNS_RESOLVER = n
975 depends on AX25 = n
976 depends on ATALK = n
977
978 # Filesystems
979 depends on USB_DEVICEFS = n
980 depends on USB_GADGETFS = n
981 depends on USB_FUNCTIONFS = n
982 depends on DEVTMPFS = n
983 depends on XENFS = n
984
985 depends on 9P_FS = n
986 depends on ADFS_FS = n
987 depends on AFFS_FS = n
988 depends on AFS_FS = n
989 depends on AUTOFS4_FS = n
990 depends on BEFS_FS = n
991 depends on BFS_FS = n
992 depends on BTRFS_FS = n
993 depends on CEPH_FS = n
994 depends on CIFS = n
995 depends on CODA_FS = n
996 depends on CONFIGFS_FS = n
997 depends on CRAMFS = n
998 depends on DEBUG_FS = n
999 depends on ECRYPT_FS = n
1000 depends on EFS_FS = n
1001 depends on EXOFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001002 depends on FAT_FS = n
1003 depends on FUSE_FS = n
1004 depends on GFS2_FS = n
1005 depends on HFS_FS = n
1006 depends on HFSPLUS_FS = n
1007 depends on HPFS_FS = n
1008 depends on HUGETLBFS = n
1009 depends on ISO9660_FS = n
1010 depends on JFFS2_FS = n
1011 depends on JFS_FS = n
1012 depends on LOGFS = n
1013 depends on MINIX_FS = n
1014 depends on NCP_FS = n
1015 depends on NFSD = n
1016 depends on NFS_FS = n
1017 depends on NILFS2_FS = n
1018 depends on NTFS_FS = n
1019 depends on OCFS2_FS = n
1020 depends on OMFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001021 depends on QNX4FS_FS = n
1022 depends on QNX6FS_FS = n
1023 depends on REISERFS_FS = n
1024 depends on SQUASHFS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001025 depends on SYSV_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001026 depends on UBIFS_FS = n
1027 depends on UDF_FS = n
1028 depends on UFS_FS = n
1029 depends on VXFS_FS = n
1030 depends on XFS_FS = n
1031
1032 depends on !UML || HOSTFS = n
1033
1034 # The rare drivers that won't build
1035 depends on AIRO = n
1036 depends on AIRO_CS = n
1037 depends on TUN = n
1038 depends on INFINIBAND_QIB = n
1039 depends on BLK_DEV_LOOP = n
1040 depends on ANDROID_BINDER_IPC = n
1041
1042 # Security modules
1043 depends on SECURITY_TOMOYO = n
1044 depends on SECURITY_APPARMOR = n
1045
Eric W. Biederman5673a942011-11-17 10:23:55 -08001046config UIDGID_STRICT_TYPE_CHECKS
1047 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001048 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001049 default n
1050 help
1051 While the nececessary conversions are being added to all subsystems this option allows
1052 the code to continue to build for unconverted subsystems.
1053
1054 Say Y here if you want the strict type checking enabled
1055
Mike Galbraith5091faa2010-11-30 14:18:03 +01001056config SCHED_AUTOGROUP
1057 bool "Automatic process group scheduling"
1058 select EVENTFD
1059 select CGROUPS
1060 select CGROUP_SCHED
1061 select FAIR_GROUP_SCHED
1062 help
1063 This option optimizes the scheduler for common desktop workloads by
1064 automatically creating and populating task groups. This separation
1065 of workloads isolates aggressive CPU burners (like build jobs) from
1066 desktop applications. Task group autogeneration is currently based
1067 upon task session.
1068
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001069config MM_OWNER
1070 bool
1071
1072config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001073 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001074 depends on SYSFS
1075 default n
1076 help
1077 This option adds code that switches the layout of the "block" class
1078 devices, to not show up in /sys/class/block/, but only in
1079 /sys/block/.
1080
1081 This switch is only active when the sysfs.deprecated=1 boot option is
1082 passed or the SYSFS_DEPRECATED_V2 option is set.
1083
1084 This option allows new kernels to run on old distributions and tools,
1085 which might get confused by /sys/class/block/. Since 2007/2008 all
1086 major distributions and tools handle this just fine.
1087
1088 Recent distributions and userspace tools after 2009/2010 depend on
1089 the existence of /sys/class/block/, and will not work with this
1090 option enabled.
1091
1092 Only if you are using a new kernel on an old distribution, you might
1093 need to say Y here.
1094
1095config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001096 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001097 default n
1098 depends on SYSFS
1099 depends on SYSFS_DEPRECATED
1100 help
1101 Enable deprecated sysfs by default.
1102
1103 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1104 option.
1105
1106 Only if you are using a new kernel on an old distribution, you might
1107 need to say Y here. Even then, odds are you would not need it
1108 enabled, you can always pass the boot option if absolutely necessary.
1109
1110config RELAY
1111 bool "Kernel->user space relay support (formerly relayfs)"
1112 help
1113 This option enables support for relay interface support in
1114 certain file systems (such as debugfs).
1115 It is designed to provide an efficient mechanism for tools and
1116 facilities to relay large amounts of data from kernel space to
1117 user space.
1118
1119 If unsure, say N.
1120
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001121config BLK_DEV_INITRD
1122 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1123 depends on BROKEN || !FRV
1124 help
1125 The initial RAM filesystem is a ramfs which is loaded by the
1126 boot loader (loadlin or lilo) and that is mounted as root
1127 before the normal boot procedure. It is typically used to
1128 load modules needed to mount the "real" root file system,
1129 etc. See <file:Documentation/initrd.txt> for details.
1130
1131 If RAM disk support (BLK_DEV_RAM) is also included, this
1132 also enables initial RAM disk (initrd) support and adds
1133 15 Kbytes (more on some other architectures) to the kernel size.
1134
1135 If unsure say Y.
1136
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001137if BLK_DEV_INITRD
1138
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001139source "usr/Kconfig"
1140
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001141endif
1142
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001143config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001144 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001145 help
1146 Enabling this option will pass "-Os" instead of "-O2" to gcc
1147 resulting in a smaller kernel.
1148
jkacur775a7222008-07-16 00:31:16 +02001149 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001150
Randy Dunlap08470622006-09-30 23:28:13 -07001151config SYSCTL
1152 bool
1153
Randy Dunlapb943c462009-03-10 12:55:46 -07001154config ANON_INODES
1155 bool
1156
David Rientjes6a108a12011-01-20 14:44:16 -08001157menuconfig EXPERT
1158 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001159 # Unhide debug options, to make the on-by-default options visible
1160 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 help
1162 This option allows certain base kernel options and settings
1163 to be disabled or tweaked. This is for specialized
1164 environments which can tolerate a "non-standard" kernel.
1165 Only use this if you really know what you are doing.
1166
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001167config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001168 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -07001169 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 -07001170 default y
1171 help
1172 This enables the legacy 16-bit UID syscall wrappers.
1173
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001174config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001175 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001176 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001177 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001178 select SYSCTL
1179 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001180 sys_sysctl uses binary paths that have been found challenging
1181 to properly maintain and use. The interface in /proc/sys
1182 using paths with ascii names is now the primary path to this
1183 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001184
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001185 Almost nothing using the binary sysctl interface so if you are
1186 trying to save some space it is probably safe to disable this,
1187 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001188
WANG Congc736de62011-11-02 13:39:25 -07001189 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001190
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001192 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 default y
1194 help
1195 Say Y here to let the kernel print out symbolic crash information and
1196 symbolic stack backtraces. This increases the size of the kernel
1197 somewhat, as all symbols have to be loaded into the kernel image.
1198
1199config KALLSYMS_ALL
1200 bool "Include all symbols in kallsyms"
1201 depends on DEBUG_KERNEL && KALLSYMS
1202 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001203 Normally kallsyms only contains the symbols of functions for nicer
1204 OOPS messages and backtraces (i.e., symbols from the text and inittext
1205 sections). This is sufficient for most cases. And only in very rare
1206 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1207 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001209 This option makes sure that all symbols are loaded into the kernel
1210 image (i.e., symbols from all sections) in cost of increased kernel
1211 size (depending on the kernel configuration, it may be 300KiB or
1212 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001214 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001215
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001216config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001217 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001218 default y
1219 help
1220 This option is provided for the case where no hotplug or uevent
1221 capabilities is wanted by the kernel. You should only consider
1222 disabling this option for embedded systems that do not use modules, a
1223 dynamic /dev tree, or dynamic device discovery. Just say Y.
1224
Matt Mackalld59745c2005-05-01 08:59:02 -07001225config PRINTK
1226 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001227 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001228 help
1229 This option enables normal printk support. Removing it
1230 eliminates most of the message strings from the kernel image
1231 and makes the kernel more or less silent. As this makes it
1232 very difficult to diagnose system problems, saying N here is
1233 strongly discouraged.
1234
Matt Mackallc8538a72005-05-01 08:59:01 -07001235config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001236 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001237 default y
1238 help
1239 Disabling this option eliminates support for BUG and WARN, reducing
1240 the size of your kernel image and potentially quietly ignoring
1241 numerous fatal conditions. You should only consider disabling this
1242 option for embedded systems with no facilities for reporting errors.
1243 Just say Y.
1244
Matt Mackall708e9a72006-01-08 01:05:25 -08001245config ELF_CORE
1246 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001247 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001248 help
1249 Enable support for generating core dumps. Disabling saves about 4k.
1250
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001251
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001252config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001253 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001254 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001255 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001256 default y
1257 help
1258 This option allows to disable the internal PC-Speaker
1259 support, saving some memory.
1260
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001261config HAVE_PCSPKR_PLATFORM
1262 bool
1263
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264config BASE_FULL
1265 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001266 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 help
1268 Disabling this option reduces the size of miscellaneous core
1269 kernel data structures. This saves memory on small machines,
1270 but may reduce performance.
1271
1272config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001273 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001275 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 help
1277 Disabling this option will cause the kernel to be built without
1278 support for "fast userspace mutexes". The resulting kernel may not
1279 run glibc-based applications correctly.
1280
1281config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001282 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001284 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 help
1286 Disabling this option will cause the kernel to be built without
1287 support for epoll family of system calls.
1288
Davide Libenzifba2afa2007-05-10 22:23:13 -07001289config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001290 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001291 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001292 default y
1293 help
1294 Enable the signalfd() system call that allows to receive signals
1295 on a file descriptor.
1296
1297 If unsure, say Y.
1298
Davide Libenzib215e282007-05-10 22:23:16 -07001299config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001300 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001301 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001302 default y
1303 help
1304 Enable the timerfd() system call that allows to receive timer
1305 events on a file descriptor.
1306
1307 If unsure, say Y.
1308
Davide Libenzie1ad7462007-05-10 22:23:19 -07001309config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001310 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001311 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001312 default y
1313 help
1314 Enable the eventfd() system call that allows to receive both
1315 kernel notification (ie. KAIO) or userspace notifications.
1316
1317 If unsure, say Y.
1318
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001320 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 default y
1322 depends on MMU
1323 help
1324 The shmem is an internal filesystem used to manage shared memory.
1325 It is backed by swap and manages resource limits. It is also exported
1326 to userspace as tmpfs if TMPFS is enabled. Disabling this
1327 option replaces shmem and tmpfs with the much simpler ramfs code,
1328 which may be appropriate on small systems without swap.
1329
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001330config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001331 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001332 default y
1333 help
1334 This option enables POSIX asynchronous I/O which may by used
1335 by some high performance threaded applications. Disabling
1336 this option saves about 7k.
1337
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001338config EMBEDDED
1339 bool "Embedded system"
1340 select EXPERT
1341 help
1342 This option should be enabled if compiling the kernel for
1343 an embedded system so certain expert options are available
1344 for configuration.
1345
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001346config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001347 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001348 help
1349 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001350
Peter Zijlstra906010b2009-09-21 16:08:49 +02001351config PERF_USE_VMALLOC
1352 bool
1353 help
1354 See tools/perf/design.txt for details
1355
Ingo Molnar57c0c152009-09-21 12:20:38 +02001356menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001357
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001358config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001359 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001360 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001361 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001362 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001363 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001364 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001365 Enable kernel support for various performance events provided
1366 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001367
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001368 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001369 use of generic tracepoints.
1370
1371 Most modern CPUs support performance events via performance
1372 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001373 types of hw events: such as instructions executed, cachemisses
1374 suffered, or branches mis-predicted - without slowing down the
1375 kernel or applications. These registers can also trigger interrupts
1376 when a threshold number of events have passed - and can thus be
1377 used to profile the code that runs on that CPU.
1378
Ingo Molnar57c0c152009-09-21 12:20:38 +02001379 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001380 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001381 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001382 provides per task and per CPU counters, and it provides event
1383 capabilities on top of those.
1384
1385 Say Y if unsure.
1386
Peter Zijlstra906010b2009-09-21 16:08:49 +02001387config DEBUG_PERF_USE_VMALLOC
1388 default n
1389 bool "Debug: use vmalloc to back perf mmap() buffers"
1390 depends on PERF_EVENTS && DEBUG_KERNEL
1391 select PERF_USE_VMALLOC
1392 help
1393 Use vmalloc memory to back perf mmap() buffers.
1394
1395 Mostly useful for debugging the vmalloc code on platforms
1396 that don't require it.
1397
1398 Say N if unsure.
1399
Thomas Gleixner0793a612008-12-04 20:12:29 +01001400endmenu
1401
Christoph Lameterf8891e52006-06-30 01:55:45 -07001402config VM_EVENT_COUNTERS
1403 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001404 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001405 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001406 VM event counters are needed for event counts to be shown.
1407 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001408 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001409 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001410
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001411config PCI_QUIRKS
1412 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001413 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001414 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001415 help
1416 This enables workarounds for various PCI chipset
1417 bugs/quirks. Disable this only if your target machine is
1418 unaffected by PCI quirks.
1419
Christoph Lameter41ecc552007-05-09 02:32:44 -07001420config SLUB_DEBUG
1421 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001422 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001423 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001424 help
1425 SLUB has extensive debug support features. Disabling these can
1426 result in significant savings in code size. This also disables
1427 SLUB sysfs support. /sys/slab will not exist and there will be
1428 no support for cache validation etc.
1429
Randy Dunlapb943c462009-03-10 12:55:46 -07001430config COMPAT_BRK
1431 bool "Disable heap randomization"
1432 default y
1433 help
1434 Randomizing heap placement makes heap exploits harder, but it
1435 also breaks ancient binaries (including anything libc5 based).
1436 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001437 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001438 /proc/sys/kernel/randomize_va_space to 2.
1439
1440 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1441
Christoph Lameter81819f02007-05-06 14:49:36 -07001442choice
1443 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001444 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001445 help
1446 This option allows to select a slab allocator.
1447
1448config SLAB
1449 bool "SLAB"
1450 help
1451 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001452 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001453 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001454
1455config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001456 bool "SLUB (Unqueued Allocator)"
1457 help
1458 SLUB is a slab allocator that minimizes cache line usage
1459 instead of managing queues of cached objects (SLAB approach).
1460 Per cpu caching is realized using slabs of objects instead
1461 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001462 and has enhanced diagnostics. SLUB is the default choice for
1463 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001464
1465config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001466 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001467 bool "SLOB (Simple Allocator)"
1468 help
Matt Mackall37291452008-02-04 22:29:38 -08001469 SLOB replaces the stock allocator with a drastically simpler
1470 allocator. SLOB is generally more space efficient but
1471 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001472
1473endchoice
1474
Jie Zhangea637632009-12-14 18:00:02 -08001475config MMAP_ALLOW_UNINITIALIZED
1476 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001477 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001478 default n
1479 help
1480 Normally, and according to the Linux spec, anonymous memory obtained
1481 from mmap() has it's contents cleared before it is passed to
1482 userspace. Enabling this config option allows you to request that
1483 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1484 providing a huge performance boost. If this option is not enabled,
1485 then the flag will be ignored.
1486
1487 This is taken advantage of by uClibc's malloc(), and also by
1488 ELF-FDPIC binfmt's brk and stack allocator.
1489
1490 Because of the obvious security issues, this option should only be
1491 enabled on embedded devices where you control what is run in
1492 userspace. Since that isn't generally a problem on no-MMU systems,
1493 it is normally safe to say Y here.
1494
1495 See Documentation/nommu-mmap.txt for more information.
1496
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001497config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001498 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001499 help
1500 Say Y here to enable the extended profiling support mechanisms used
1501 by profilers such as OProfile.
1502
Ingo Molnar5f87f112008-07-23 14:15:22 +02001503#
1504# Place an empty function call at each tracepoint site. Can be
1505# dynamically changed for a probe function.
1506#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001507config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001508 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001509
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001510source "arch/Kconfig"
1511
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512endmenu # General setup
1513
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001514config HAVE_GENERIC_DMA_COHERENT
1515 bool
1516 default n
1517
Linus Torvalds158a9622008-01-02 13:04:48 -08001518config SLABINFO
1519 bool
1520 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001521 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001522 default y
1523
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001524config RT_MUTEXES
1525 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001526
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527config BASE_SMALL
1528 int
1529 default 0 if BASE_FULL
1530 default 1 if !BASE_FULL
1531
Jan Engelhardt66da5732007-07-15 23:39:29 -07001532menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 bool "Enable loadable module support"
1534 help
1535 Kernel modules are small pieces of compiled code which can
1536 be inserted in the running kernel, rather than being
1537 permanently built into the kernel. You use the "modprobe"
1538 tool to add (and sometimes remove) them. If you say Y here,
1539 many parts of the kernel can be built as modules (by
1540 answering M instead of Y where indicated): this is most
1541 useful for infrequently used options which are not required
1542 for booting. For more information, see the man pages for
1543 modprobe, lsmod, modinfo, insmod and rmmod.
1544
1545 If you say Y here, you will need to run "make
1546 modules_install" to put the modules under /lib/modules/
1547 where modprobe can find them (you may need to be root to do
1548 this).
1549
1550 If unsure, say Y.
1551
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001552if MODULES
1553
Linus Torvalds826e4502008-05-04 17:04:16 -07001554config MODULE_FORCE_LOAD
1555 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001556 default n
1557 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001558 Allow loading of modules without version information (ie. modprobe
1559 --force). Forced module loading sets the 'F' (forced) taint flag and
1560 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001561
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562config MODULE_UNLOAD
1563 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 help
1565 Without this option you will not be able to unload any
1566 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001567 anyway), which makes your kernel smaller, faster
1568 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569
1570config MODULE_FORCE_UNLOAD
1571 bool "Forced module unloading"
1572 depends on MODULE_UNLOAD && EXPERIMENTAL
1573 help
1574 This option allows you to force a module to unload, even if the
1575 kernel believes it is unsafe: the kernel will remove the module
1576 without waiting for anyone to stop using it (using the -f option to
1577 rmmod). This is mainly for kernel developers and desperate users.
1578 If unsure, say N.
1579
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001581 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 help
1583 Usually, you have to use modules compiled with your kernel.
1584 Saying Y here makes it sometimes possible to use modules
1585 compiled for different kernels, by adding enough information
1586 to the modules to (hopefully) spot any changes which would
1587 make them incompatible with the kernel you are running. If
1588 unsure, say N.
1589
1590config MODULE_SRCVERSION_ALL
1591 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592 help
1593 Modules which contain a MODULE_VERSION get an extra "srcversion"
1594 field inserted into their modinfo section, which contains a
1595 sum of the source files which made it. This helps maintainers
1596 see exactly which source was used to build a module (since
1597 others sometimes change the module source without updating
1598 the version). With this option, such a "srcversion" field
1599 will be created for all modules. If unsure, say N.
1600
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001601endif # MODULES
1602
Rusty Russell98a79d62008-12-13 21:19:41 +10301603config INIT_ALL_POSSIBLE
1604 bool
1605 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301606 Back when each arch used to define their own cpu_online_mask and
1607 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301608 with all 1s, and others with all 0s. When they were centralised,
1609 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001610 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301611
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612config STOP_MACHINE
1613 bool
1614 default y
1615 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1616 help
1617 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001618
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001619source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001620
1621config PREEMPT_NOTIFIERS
1622 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001623
Steffen Klassert16295be2010-01-06 19:47:10 +11001624config PADATA
1625 depends on SMP
1626 bool
1627
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001628source "kernel/Kconfig.locks"