blob: 1862c6893078868c3ddbf5e124e7c3dd8e1ed2dc [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56 drivers that have been replaced by something else, and/or are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
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530270config FHANDLE
271 bool "open by fhandle syscalls"
272 select EXPORTFS
273 help
274 If you say Y here, a user level program will be able to map
275 file names to handle and then later use the handle for
276 different file system operations. This is useful in implementing
277 userspace file servers, which now track files using handles instead
278 of names. The handle would remain the same even if file names
279 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
280 syscalls.
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282config AUDIT
283 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100284 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 help
286 Enable auditing infrastructure that can be used with another
287 kernel subsystem, such as SELinux (which requires this for
288 logging of avc messages output). Does not do system-call
289 auditing without CONFIG_AUDITSYSCALL.
290
291config AUDITSYSCALL
292 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100293 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 default y if SECURITY_SELINUX
295 help
296 Enable low-overhead system-call auditing infrastructure that
297 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500298 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
Eric Paris939a67f2009-12-17 20:12:06 -0500300config AUDIT_WATCH
301 def_bool y
302 depends on AUDITSYSCALL
303 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
Al Viro74c3cbe2007-07-22 08:04:18 -0400305config AUDIT_TREE
306 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400307 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500308 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400309
Eric Paris633b4542012-01-03 14:23:08 -0500310config AUDIT_LOGINUID_IMMUTABLE
311 bool "Make audit loginuid immutable"
312 depends on AUDIT
313 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800314 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500315 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
316 but should instead only allow setting its loginuid if it was never
317 previously set. On systems which use systemd or a similar central
318 process to restart login services this should be set to true. On older
319 systems in which an admin would typically have to directly stop and
320 start processes this should be set to false. Setting this to true allows
321 one to drop potentially dangerous capabilites from the login tasks,
322 but may not be backwards compatible with older init systems.
323
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000324source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200325source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000326
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200327menu "CPU/Task time and stats accounting"
328
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200329choice
330 prompt "Cputime accounting"
331 default TICK_CPU_ACCOUNTING if !PPC64
332 default VIRT_CPU_ACCOUNTING if PPC64
333
334# Kind of a stub config for the pure tick based cputime accounting
335config TICK_CPU_ACCOUNTING
336 bool "Simple tick based cputime accounting"
337 depends on !S390
338 help
339 This is the basic tick based cputime accounting that maintains
340 statistics about user, system and idle time spent on per jiffies
341 granularity.
342
343 If unsure, say Y.
344
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200345config VIRT_CPU_ACCOUNTING
346 bool "Deterministic task and CPU time accounting"
347 depends on HAVE_VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200348 help
349 Select this option to enable more accurate task and CPU time
350 accounting. This is done by reading a CPU counter on each
351 kernel entry and exit and on transitions within the kernel
352 between system, softirq and hardirq state, so there is a
353 small performance impact. In the case of s390 or IBM POWER > 5,
354 this also enables accounting of stolen time on logically-partitioned
355 systems.
356
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200357config IRQ_TIME_ACCOUNTING
358 bool "Fine granularity task level IRQ time accounting"
359 depends on HAVE_IRQ_TIME_ACCOUNTING
360 help
361 Select this option to enable fine granularity task irq time
362 accounting. This is done by reading a timestamp on each
363 transitions between softirq and hardirq state, so there can be a
364 small performance impact.
365
366 If in doubt, say N here.
367
368endchoice
369
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200370config BSD_PROCESS_ACCT
371 bool "BSD Process Accounting"
372 help
373 If you say Y here, a user level program will be able to instruct the
374 kernel (via a special system call) to write process accounting
375 information to a file: whenever a process exits, information about
376 that process will be appended to the file by the kernel. The
377 information includes things such as creation time, owning user,
378 command name, memory usage, controlling terminal etc. (the complete
379 list is in the struct acct in <file:include/linux/acct.h>). It is
380 up to the user level program to do useful things with this
381 information. This is generally a good idea, so say Y.
382
383config BSD_PROCESS_ACCT_V3
384 bool "BSD Process Accounting version 3 file format"
385 depends on BSD_PROCESS_ACCT
386 default n
387 help
388 If you say Y here, the process accounting information is written
389 in a new file format that also logs the process IDs of each
390 process and it's parent. Note that this file format is incompatible
391 with previous v0/v1/v2 file formats, so you will need updated tools
392 for processing it. A preliminary version of these tools is available
393 at <http://www.gnu.org/software/acct/>.
394
395config TASKSTATS
396 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
397 depends on NET
398 default n
399 help
400 Export selected statistics for tasks/processes through the
401 generic netlink interface. Unlike BSD process accounting, the
402 statistics are available during the lifetime of tasks/processes as
403 responses to commands. Like BSD accounting, they are sent to user
404 space on task exit.
405
406 Say N if unsure.
407
408config TASK_DELAY_ACCT
409 bool "Enable per-task delay accounting (EXPERIMENTAL)"
410 depends on TASKSTATS
411 help
412 Collect information on time spent by a task waiting for system
413 resources like cpu, synchronous block I/O completion and swapping
414 in pages. Such statistics can help in setting a task's priorities
415 relative to other tasks for cpu, io, rss limits etc.
416
417 Say N if unsure.
418
419config TASK_XACCT
420 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
421 depends on TASKSTATS
422 help
423 Collect extended task accounting data and send the data
424 to userland for processing over the taskstats interface.
425
426 Say N if unsure.
427
428config TASK_IO_ACCOUNTING
429 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
430 depends on TASK_XACCT
431 help
432 Collect information on the number of bytes of storage I/O which this
433 task has caused.
434
435 Say N if unsure.
436
437endmenu # "CPU/Task time and stats accounting"
438
Mike Travisc903ff82009-01-15 12:28:29 -0800439menu "RCU Subsystem"
440
441choice
442 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700443 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800444
Mike Travisc903ff82009-01-15 12:28:29 -0800445config TREE_RCU
446 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700447 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800448 help
449 This option selects the RCU implementation that is
450 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700451 thousands of CPUs. It also scales down nicely to
452 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800453
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700454config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700455 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700456 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700457 help
458 This option selects the RCU implementation that is
459 designed for very large SMP systems with hundreds or
460 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700461 is also required. It also scales down nicely to
462 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700463
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700464config TINY_RCU
465 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700466 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700467 help
468 This option selects the RCU implementation that is
469 designed for UP systems from which real-time response
470 is not required. This option greatly reduces the
471 memory footprint of RCU.
472
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700473config TINY_PREEMPT_RCU
474 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700475 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700476 help
477 This option selects the RCU implementation that is designed
478 for real-time UP systems. This option greatly reduces the
479 memory footprint of RCU.
480
Mike Travisc903ff82009-01-15 12:28:29 -0800481endchoice
482
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700483config PREEMPT_RCU
484 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
485 help
486 This option enables preemptible-RCU code that is common between
487 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
488
Mike Travisc903ff82009-01-15 12:28:29 -0800489config RCU_FANOUT
490 int "Tree-based hierarchical RCU fanout value"
491 range 2 64 if 64BIT
492 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700493 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800494 default 64 if 64BIT
495 default 32 if !64BIT
496 help
497 This option controls the fanout of hierarchical implementations
498 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700499 large numbers of CPUs. This value must be at least the fourth
500 root of NR_CPUS, which allows NR_CPUS to be insanely large.
501 The default value of RCU_FANOUT should be used for production
502 systems, but if you are stress-testing the RCU implementation
503 itself, small RCU_FANOUT values allow you to test large-system
504 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800505
506 Select a specific number if testing RCU itself.
507 Take the default if unsure.
508
Paul E. McKenney8932a632012-04-19 12:20:14 -0700509config RCU_FANOUT_LEAF
510 int "Tree-based hierarchical RCU leaf-level fanout value"
511 range 2 RCU_FANOUT if 64BIT
512 range 2 RCU_FANOUT if !64BIT
513 depends on TREE_RCU || TREE_PREEMPT_RCU
514 default 16
515 help
516 This option controls the leaf-level fanout of hierarchical
517 implementations of RCU, and allows trading off cache misses
518 against lock contention. Systems that synchronize their
519 scheduling-clock interrupts for energy-efficiency reasons will
520 want the default because the smaller leaf-level fanout keeps
521 lock contention levels acceptably low. Very large systems
522 (hundreds or thousands of CPUs) will instead want to set this
523 value to the maximum value possible in order to reduce the
524 number of cache misses incurred during RCU's grace-period
525 initialization. These systems tend to run CPU-bound, and thus
526 are not helped by synchronized interrupts, and thus tend to
527 skew them, which reduces lock contention enough that large
528 leaf-level fanouts work well.
529
530 Select a specific number if testing RCU itself.
531
532 Select the maximum permissible value for large systems.
533
534 Take the default if unsure.
535
Mike Travisc903ff82009-01-15 12:28:29 -0800536config RCU_FANOUT_EXACT
537 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700538 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800539 default n
540 help
541 This option forces use of the exact RCU_FANOUT value specified,
542 regardless of imbalances in the hierarchy. This is useful for
543 testing RCU itself, and might one day be useful on systems with
544 strong NUMA behavior.
545
546 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
547
548 Say N if unsure.
549
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800550config RCU_FAST_NO_HZ
551 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700552 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800553 default n
554 help
555 This option causes RCU to attempt to accelerate grace periods
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700556 in order to allow CPUs to enter dynticks-idle state more
557 quickly. On the other hand, this option increases the overhead
558 of the dynticks-idle checking, particularly on systems with
559 large numbers of CPUs.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800560
561 Say Y if energy efficiency is critically important, particularly
562 if you have relatively few CPUs.
563
564 Say N if you are unsure.
565
Mike Travisc903ff82009-01-15 12:28:29 -0800566config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700567 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800568 select DEBUG_FS
569 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700570 This option provides tracing for the TREE_RCU and
571 TREE_PREEMPT_RCU implementations, permitting Makefile to
572 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800573
Paul E. McKenney24278d12010-09-27 17:25:23 -0700574config RCU_BOOST
575 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800576 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700577 default n
578 help
579 This option boosts the priority of preempted RCU readers that
580 block the current preemptible RCU grace period for too long.
581 This option also prevents heavy loads from blocking RCU
582 callback invocation for all flavors of RCU.
583
584 Say Y here if you are working with real-time apps or heavy loads
585 Say N here if you are unsure.
586
587config RCU_BOOST_PRIO
588 int "Real-time priority to boost RCU readers to"
589 range 1 99
590 depends on RCU_BOOST
591 default 1
592 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700593 This option specifies the real-time priority to which long-term
594 preempted RCU readers are to be boosted. If you are working
595 with a real-time application that has one or more CPU-bound
596 threads running at a real-time priority level, you should set
597 RCU_BOOST_PRIO to a priority higher then the highest-priority
598 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
599 of 1 is appropriate in the common case, which is real-time
600 applications that do not have any CPU-bound threads.
601
602 Some real-time applications might not have a single real-time
603 thread that saturates a given CPU, but instead might have
604 multiple real-time threads that, taken together, fully utilize
605 that CPU. In this case, you should set RCU_BOOST_PRIO to
606 a priority higher than the lowest-priority thread that is
607 conspiring to prevent the CPU from running any non-real-time
608 tasks. For example, if one thread at priority 10 and another
609 thread at priority 5 are between themselves fully consuming
610 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
611 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700612
613 Specify the real-time priority, or take the default if unsure.
614
615config RCU_BOOST_DELAY
616 int "Milliseconds to delay boosting after RCU grace-period start"
617 range 0 3000
618 depends on RCU_BOOST
619 default 500
620 help
621 This option specifies the time to wait after the beginning of
622 a given grace period before priority-boosting preempted RCU
623 readers blocking that grace period. Note that any RCU reader
624 blocking an expedited RCU grace period is boosted immediately.
625
626 Accept the default if unsure.
627
Mike Travisc903ff82009-01-15 12:28:29 -0800628endmenu # "RCU Subsystem"
629
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700631 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 ---help---
633 This option enables the complete Linux kernel ".config" file
634 contents to be saved in the kernel. It provides documentation
635 of which kernel options are used in a running kernel or in an
636 on-disk kernel. This information can be extracted from the kernel
637 image file with the script scripts/extract-ikconfig and used as
638 input to rebuild the current kernel or to build another kernel.
639 It can also be extracted from a running kernel by reading
640 /proc/config.gz if enabled (below).
641
642config IKCONFIG_PROC
643 bool "Enable access to .config through /proc/config.gz"
644 depends on IKCONFIG && PROC_FS
645 ---help---
646 This option enables access to the kernel configuration file
647 through /proc/config.gz.
648
Alistair John Strachan794543a2007-05-08 00:31:15 -0700649config LOG_BUF_SHIFT
650 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
651 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700652 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700653 help
654 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700655 Examples:
656 17 => 128 KB
657 16 => 64 KB
658 15 => 32 KB
659 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700660 13 => 8 KB
661 12 => 4 KB
662
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800663#
664# Architectures with an unreliable sched_clock() should select this:
665#
666config HAVE_UNSTABLE_SCHED_CLOCK
667 bool
668
Li Zefan23964d22009-01-15 13:50:58 -0800669menuconfig CGROUPS
670 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800671 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700672 help
Li Zefan23964d22009-01-15 13:50:58 -0800673 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800674 use with process control subsystems such as Cpusets, CFS, memory
675 controls or device isolation.
676 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800677 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800678 - Documentation/cgroups/ (features for grouping, isolation
679 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700680
681 Say N if unsure.
682
Li Zefan23964d22009-01-15 13:50:58 -0800683if CGROUPS
684
Paul Menage006cb992007-10-18 23:39:43 -0700685config CGROUP_DEBUG
686 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700687 default n
Paul Menage006cb992007-10-18 23:39:43 -0700688 help
689 This option enables a simple cgroup subsystem that
690 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800691 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700692
Li Zefan23964d22009-01-15 13:50:58 -0800693 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700694
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700695config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800696 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800697 help
698 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700699 cgroup.
700
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700701config CGROUP_DEVICE
702 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700703 help
704 Provides a cgroup implementing whitelists for devices which
705 a process in the cgroup can mknod or open.
706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707config CPUSETS
708 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700710 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 allow dynamically partitioning a system into sets of CPUs and
712 Memory Nodes and assigning tasks to run only within those sets.
713 This is primarily useful on large SMP or NUMA systems.
714
715 Say N if unsure.
716
Li Zefan23964d22009-01-15 13:50:58 -0800717config PROC_PID_CPUSET
718 bool "Include legacy /proc/<pid>/cpuset file"
719 depends on CPUSETS
720 default y
721
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100722config CGROUP_CPUACCT
723 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100724 help
725 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800726 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100727
Pavel Emelianove552b662008-02-07 00:13:49 -0800728config RESOURCE_COUNTERS
729 bool "Resource counters"
730 help
731 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800732 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800733
Andrew Mortonc255a452012-07-31 16:43:02 -0700734config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800735 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700736 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700737 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800738 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700739 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100740 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800741
742 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700743 associated with each page of memory in the system. By this,
744 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
745 usage tracking struct at boot. Total amount of this is printed out
746 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800747
748 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700749 sure you need the memory resource controller. Even when you enable
750 this, you can set "cgroup_disable=memory" at your boot option to
751 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800752 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800753
Balbir Singhcf475ad2008-04-29 01:00:16 -0700754 This config option also selects MM_OWNER config option, which
755 could in turn add some fork/exit overhead.
756
Andrew Mortonc255a452012-07-31 16:43:02 -0700757config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700758 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700759 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800760 help
761 Add swap management feature to memory resource controller. When you
762 enable this, you can limit mem+swap usage per cgroup. In other words,
763 when you disable this, memory resource controller has no cares to
764 usage of swap...a process can exhaust all of the swap. This extension
765 is useful when you want to avoid exhaustion swap but this itself
766 adds more overheads and consumes memory for remembering information.
767 Especially if you use 32bit system or small memory system, please
768 be careful about enabling this. When memory resource controller
769 is disabled by boot option, this will be automatically disabled and
770 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700771 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700772 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
773 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700774config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800775 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700776 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800777 default y
778 help
779 Memory Resource Controller Swap Extension comes with its price in
780 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700781 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800782 and let the user enable it by swapaccount boot command line
783 parameter should have this option unselected.
784 For those who want to have the feature enabled by default should
785 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700786 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700787config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000788 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700789 depends on MEMCG && EXPERIMENTAL
Glauber Costae5671df2011-12-11 21:47:01 +0000790 default n
791 help
792 The Kernel Memory extension for Memory Resource Controller can limit
793 the amount of memory used by kernel objects in the system. Those are
794 fundamentally different from the entities handled by the standard
795 Memory Controller, which are page-based, and can be swapped. Users of
796 the kmem extension can use it to guarantee that no group of processes
797 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800798
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700799config CGROUP_HUGETLB
800 bool "HugeTLB Resource Controller for Control Groups"
801 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
802 default n
803 help
804 Provides a cgroup Resource Controller for HugeTLB pages.
805 When you enable this, you can put a per cgroup limit on HugeTLB usage.
806 The limit is enforced during page fault. Since HugeTLB doesn't
807 support page reclaim, enforcing the limit at page fault time implies
808 that, the application will get SIGBUS signal if it tries to access
809 HugeTLB pages beyond its limit. This requires the application to know
810 beforehand how much HugeTLB pages it would require for its use. The
811 control group is tracked in the third page lru pointer. This means
812 that we cannot use the controller with huge page less than 3 pages.
813
Stephane Eraniane5d13672011-02-14 11:20:01 +0200814config CGROUP_PERF
815 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
816 depends on PERF_EVENTS && CGROUPS
817 help
818 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800819 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200820 designated cpu.
821
822 Say N if unsure.
823
Dhaval Giani7c941432010-01-20 13:26:18 +0100824menuconfig CGROUP_SCHED
825 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100826 default n
827 help
828 This feature lets CPU scheduler recognize task groups and control CPU
829 bandwidth allocation to such task groups. It uses cgroups to group
830 tasks.
831
832if CGROUP_SCHED
833config FAIR_GROUP_SCHED
834 bool "Group scheduling for SCHED_OTHER"
835 depends on CGROUP_SCHED
836 default CGROUP_SCHED
837
Paul Turnerab84d312011-07-21 09:43:28 -0700838config CFS_BANDWIDTH
839 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
840 depends on EXPERIMENTAL
841 depends on FAIR_GROUP_SCHED
842 default n
843 help
844 This option allows users to define CPU bandwidth rates (limits) for
845 tasks running within the fair group scheduler. Groups with no limit
846 set are considered to be unconstrained and will run with no
847 restriction.
848 See tip/Documentation/scheduler/sched-bwc.txt for more information.
849
Dhaval Giani7c941432010-01-20 13:26:18 +0100850config RT_GROUP_SCHED
851 bool "Group scheduling for SCHED_RR/FIFO"
852 depends on EXPERIMENTAL
853 depends on CGROUP_SCHED
854 default n
855 help
856 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800857 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100858 schedule realtime tasks for non-root users until you allocate
859 realtime bandwidth for them.
860 See Documentation/scheduler/sched-rt-group.txt for more information.
861
862endif #CGROUP_SCHED
863
Vivek Goyalafc24d42010-04-26 19:27:56 +0200864config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800865 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700866 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200867 default n
868 ---help---
869 Generic block IO controller cgroup interface. This is the common
870 cgroup interface which should be used by various IO controlling
871 policies.
872
873 Currently, CFQ IO scheduler uses it to recognize task groups and
874 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400875 to such task groups. It is also used by bio throttling logic in
876 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200877
878 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400879 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000880 enabling proportional weight division of disk bandwidth in CFQ, set
881 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000882 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200883
884 See Documentation/cgroups/blkio-controller.txt for more information.
885
886config DEBUG_BLK_CGROUP
887 bool "Enable Block IO controller debugging"
888 depends on BLK_CGROUP
889 default n
890 ---help---
891 Enable some debugging help. Currently it exports additional stat
892 files in a cgroup which can be useful for debugging.
893
Li Zefan23964d22009-01-15 13:50:58 -0800894endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800895
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800896config CHECKPOINT_RESTORE
897 bool "Checkpoint/restore support" if EXPERT
898 default n
899 help
900 Enables additional kernel features in a sake of checkpoint/restore.
901 In particular it adds auxiliary prctl codes to setup process text,
902 data and heap segment sizes, and a few additional /proc filesystem
903 entries.
904
905 If unsure, say N here.
906
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700907menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800908 bool "Namespaces support" if EXPERT
909 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -0800910 help
911 Provides the way to make tasks work with different objects using
912 the same id. For example same IPC id may refer to different objects
913 or same user id or pid may refer to different tasks when used in
914 different namespaces.
915
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700916if NAMESPACES
917
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800918config UTS_NS
919 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700920 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -0800921 help
922 In this namespace tasks see different info provided with the
923 uname() system call
924
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800925config IPC_NS
926 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700927 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700928 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800929 help
930 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700931 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800932
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800933config USER_NS
934 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700935 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700936 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -0800937 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700938
Eric W. Biederman5673a942011-11-17 10:23:55 -0800939 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -0800940 help
941 This allows containers, i.e. vservers, to use user namespaces
942 to provide different user info for different servers.
943 If unsure, say N.
944
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800945config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -0700946 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700947 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800948 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +0300949 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +0100950 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -0800951 pid namespaces. This is a building block of containers.
952
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800953config NET_NS
954 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700955 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -0700956 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -0800957 help
958 Allow user space to create what appear to be multiple instances
959 of the network stack.
960
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700961endif # NAMESPACES
962
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700963config UIDGID_CONVERTED
964 # True if all of the selected software conmponents are known
965 # to have uid_t and gid_t converted to kuid_t and kgid_t
966 # where appropriate and are otherwise safe to use with
967 # the user namespace.
968 bool
969 default y
970
971 # List of kernel pieces that need user namespace work
972 # Features
Eric W. Biedermane1c972b2012-04-21 04:09:01 -0700973 depends on SYSVIPC = n
974 depends on IMA = n
975 depends on EVM = n
976 depends on KEYS = n
977 depends on AUDIT = n
978 depends on AUDITSYSCALL = n
979 depends on TASKSTATS = n
980 depends on TRACING = n
981 depends on FS_POSIX_ACL = n
982 depends on QUOTA = n
983 depends on QUOTACTL = n
984 depends on DEBUG_CREDENTIALS = n
985 depends on BSD_PROCESS_ACCT = n
986 depends on DRM = n
987 depends on PROC_EVENTS = n
988
989 # Networking
990 depends on NET = n
991 depends on NET_9P = n
992 depends on IPX = n
993 depends on PHONET = n
994 depends on NET_CLS_FLOW = n
995 depends on NETFILTER_XT_MATCH_OWNER = n
996 depends on NETFILTER_XT_MATCH_RECENT = n
997 depends on NETFILTER_XT_TARGET_LOG = n
998 depends on NETFILTER_NETLINK_LOG = n
999 depends on INET = n
1000 depends on IPV6 = n
1001 depends on IP_SCTP = n
1002 depends on AF_RXRPC = n
1003 depends on LLC2 = n
1004 depends on NET_KEY = n
1005 depends on INET_DIAG = n
1006 depends on DNS_RESOLVER = n
1007 depends on AX25 = n
1008 depends on ATALK = n
1009
1010 # Filesystems
1011 depends on USB_DEVICEFS = n
1012 depends on USB_GADGETFS = n
1013 depends on USB_FUNCTIONFS = n
1014 depends on DEVTMPFS = n
1015 depends on XENFS = n
1016
1017 depends on 9P_FS = n
1018 depends on ADFS_FS = n
1019 depends on AFFS_FS = n
1020 depends on AFS_FS = n
1021 depends on AUTOFS4_FS = n
1022 depends on BEFS_FS = n
1023 depends on BFS_FS = n
1024 depends on BTRFS_FS = n
1025 depends on CEPH_FS = n
1026 depends on CIFS = n
1027 depends on CODA_FS = n
1028 depends on CONFIGFS_FS = n
1029 depends on CRAMFS = n
1030 depends on DEBUG_FS = n
1031 depends on ECRYPT_FS = n
1032 depends on EFS_FS = n
1033 depends on EXOFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001034 depends on FAT_FS = n
1035 depends on FUSE_FS = n
1036 depends on GFS2_FS = n
1037 depends on HFS_FS = n
1038 depends on HFSPLUS_FS = n
1039 depends on HPFS_FS = n
1040 depends on HUGETLBFS = n
1041 depends on ISO9660_FS = n
1042 depends on JFFS2_FS = n
1043 depends on JFS_FS = n
1044 depends on LOGFS = n
1045 depends on MINIX_FS = n
1046 depends on NCP_FS = n
1047 depends on NFSD = n
1048 depends on NFS_FS = n
1049 depends on NILFS2_FS = n
1050 depends on NTFS_FS = n
1051 depends on OCFS2_FS = n
1052 depends on OMFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001053 depends on QNX4FS_FS = n
1054 depends on QNX6FS_FS = n
1055 depends on REISERFS_FS = n
1056 depends on SQUASHFS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001057 depends on SYSV_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001058 depends on UBIFS_FS = n
1059 depends on UDF_FS = n
1060 depends on UFS_FS = n
1061 depends on VXFS_FS = n
1062 depends on XFS_FS = n
1063
1064 depends on !UML || HOSTFS = n
1065
1066 # The rare drivers that won't build
1067 depends on AIRO = n
1068 depends on AIRO_CS = n
1069 depends on TUN = n
1070 depends on INFINIBAND_QIB = n
1071 depends on BLK_DEV_LOOP = n
1072 depends on ANDROID_BINDER_IPC = n
1073
1074 # Security modules
1075 depends on SECURITY_TOMOYO = n
1076 depends on SECURITY_APPARMOR = n
1077
Eric W. Biederman5673a942011-11-17 10:23:55 -08001078config UIDGID_STRICT_TYPE_CHECKS
1079 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001080 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001081 default n
1082 help
1083 While the nececessary conversions are being added to all subsystems this option allows
1084 the code to continue to build for unconverted subsystems.
1085
1086 Say Y here if you want the strict type checking enabled
1087
Mike Galbraith5091faa2010-11-30 14:18:03 +01001088config SCHED_AUTOGROUP
1089 bool "Automatic process group scheduling"
1090 select EVENTFD
1091 select CGROUPS
1092 select CGROUP_SCHED
1093 select FAIR_GROUP_SCHED
1094 help
1095 This option optimizes the scheduler for common desktop workloads by
1096 automatically creating and populating task groups. This separation
1097 of workloads isolates aggressive CPU burners (like build jobs) from
1098 desktop applications. Task group autogeneration is currently based
1099 upon task session.
1100
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001101config MM_OWNER
1102 bool
1103
1104config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001105 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001106 depends on SYSFS
1107 default n
1108 help
1109 This option adds code that switches the layout of the "block" class
1110 devices, to not show up in /sys/class/block/, but only in
1111 /sys/block/.
1112
1113 This switch is only active when the sysfs.deprecated=1 boot option is
1114 passed or the SYSFS_DEPRECATED_V2 option is set.
1115
1116 This option allows new kernels to run on old distributions and tools,
1117 which might get confused by /sys/class/block/. Since 2007/2008 all
1118 major distributions and tools handle this just fine.
1119
1120 Recent distributions and userspace tools after 2009/2010 depend on
1121 the existence of /sys/class/block/, and will not work with this
1122 option enabled.
1123
1124 Only if you are using a new kernel on an old distribution, you might
1125 need to say Y here.
1126
1127config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001128 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001129 default n
1130 depends on SYSFS
1131 depends on SYSFS_DEPRECATED
1132 help
1133 Enable deprecated sysfs by default.
1134
1135 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1136 option.
1137
1138 Only if you are using a new kernel on an old distribution, you might
1139 need to say Y here. Even then, odds are you would not need it
1140 enabled, you can always pass the boot option if absolutely necessary.
1141
1142config RELAY
1143 bool "Kernel->user space relay support (formerly relayfs)"
1144 help
1145 This option enables support for relay interface support in
1146 certain file systems (such as debugfs).
1147 It is designed to provide an efficient mechanism for tools and
1148 facilities to relay large amounts of data from kernel space to
1149 user space.
1150
1151 If unsure, say N.
1152
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001153config BLK_DEV_INITRD
1154 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1155 depends on BROKEN || !FRV
1156 help
1157 The initial RAM filesystem is a ramfs which is loaded by the
1158 boot loader (loadlin or lilo) and that is mounted as root
1159 before the normal boot procedure. It is typically used to
1160 load modules needed to mount the "real" root file system,
1161 etc. See <file:Documentation/initrd.txt> for details.
1162
1163 If RAM disk support (BLK_DEV_RAM) is also included, this
1164 also enables initial RAM disk (initrd) support and adds
1165 15 Kbytes (more on some other architectures) to the kernel size.
1166
1167 If unsure say Y.
1168
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001169if BLK_DEV_INITRD
1170
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001171source "usr/Kconfig"
1172
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001173endif
1174
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001175config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001176 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001177 help
1178 Enabling this option will pass "-Os" instead of "-O2" to gcc
1179 resulting in a smaller kernel.
1180
jkacur775a7222008-07-16 00:31:16 +02001181 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001182
Randy Dunlap08470622006-09-30 23:28:13 -07001183config SYSCTL
1184 bool
1185
Randy Dunlapb943c462009-03-10 12:55:46 -07001186config ANON_INODES
1187 bool
1188
David Rientjes6a108a12011-01-20 14:44:16 -08001189menuconfig EXPERT
1190 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001191 # Unhide debug options, to make the on-by-default options visible
1192 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 help
1194 This option allows certain base kernel options and settings
1195 to be disabled or tweaked. This is for specialized
1196 environments which can tolerate a "non-standard" kernel.
1197 Only use this if you really know what you are doing.
1198
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001199config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001200 bool "Enable 16-bit UID system calls" if EXPERT
David S. Miller09337f52008-04-26 03:17:12 -07001201 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 -07001202 default y
1203 help
1204 This enables the legacy 16-bit UID syscall wrappers.
1205
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001206config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001207 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001208 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001209 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001210 select SYSCTL
1211 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001212 sys_sysctl uses binary paths that have been found challenging
1213 to properly maintain and use. The interface in /proc/sys
1214 using paths with ascii names is now the primary path to this
1215 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001216
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001217 Almost nothing using the binary sysctl interface so if you are
1218 trying to save some space it is probably safe to disable this,
1219 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001220
WANG Congc736de62011-11-02 13:39:25 -07001221 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001222
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001224 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 default y
1226 help
1227 Say Y here to let the kernel print out symbolic crash information and
1228 symbolic stack backtraces. This increases the size of the kernel
1229 somewhat, as all symbols have to be loaded into the kernel image.
1230
1231config KALLSYMS_ALL
1232 bool "Include all symbols in kallsyms"
1233 depends on DEBUG_KERNEL && KALLSYMS
1234 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001235 Normally kallsyms only contains the symbols of functions for nicer
1236 OOPS messages and backtraces (i.e., symbols from the text and inittext
1237 sections). This is sufficient for most cases. And only in very rare
1238 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1239 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001241 This option makes sure that all symbols are loaded into the kernel
1242 image (i.e., symbols from all sections) in cost of increased kernel
1243 size (depending on the kernel configuration, it may be 300KiB or
1244 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001246 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001247
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001248config HOTPLUG
David Rientjes6a108a12011-01-20 14:44:16 -08001249 bool "Support for hot-pluggable devices" if EXPERT
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001250 default y
1251 help
1252 This option is provided for the case where no hotplug or uevent
1253 capabilities is wanted by the kernel. You should only consider
1254 disabling this option for embedded systems that do not use modules, a
1255 dynamic /dev tree, or dynamic device discovery. Just say Y.
1256
Matt Mackalld59745c2005-05-01 08:59:02 -07001257config PRINTK
1258 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001259 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001260 help
1261 This option enables normal printk support. Removing it
1262 eliminates most of the message strings from the kernel image
1263 and makes the kernel more or less silent. As this makes it
1264 very difficult to diagnose system problems, saying N here is
1265 strongly discouraged.
1266
Matt Mackallc8538a72005-05-01 08:59:01 -07001267config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001268 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001269 default y
1270 help
1271 Disabling this option eliminates support for BUG and WARN, reducing
1272 the size of your kernel image and potentially quietly ignoring
1273 numerous fatal conditions. You should only consider disabling this
1274 option for embedded systems with no facilities for reporting errors.
1275 Just say Y.
1276
Matt Mackall708e9a72006-01-08 01:05:25 -08001277config ELF_CORE
1278 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001279 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001280 help
1281 Enable support for generating core dumps. Disabling saves about 4k.
1282
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001283
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001284config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001285 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001286 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001287 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001288 default y
1289 help
1290 This option allows to disable the internal PC-Speaker
1291 support, saving some memory.
1292
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001293config HAVE_PCSPKR_PLATFORM
1294 bool
1295
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296config BASE_FULL
1297 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001298 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 help
1300 Disabling this option reduces the size of miscellaneous core
1301 kernel data structures. This saves memory on small machines,
1302 but may reduce performance.
1303
1304config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001305 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001307 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 help
1309 Disabling this option will cause the kernel to be built without
1310 support for "fast userspace mutexes". The resulting kernel may not
1311 run glibc-based applications correctly.
1312
1313config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001314 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001316 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 help
1318 Disabling this option will cause the kernel to be built without
1319 support for epoll family of system calls.
1320
Davide Libenzifba2afa2007-05-10 22:23:13 -07001321config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001322 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001323 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001324 default y
1325 help
1326 Enable the signalfd() system call that allows to receive signals
1327 on a file descriptor.
1328
1329 If unsure, say Y.
1330
Davide Libenzib215e282007-05-10 22:23:16 -07001331config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001332 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001333 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001334 default y
1335 help
1336 Enable the timerfd() system call that allows to receive timer
1337 events on a file descriptor.
1338
1339 If unsure, say Y.
1340
Davide Libenzie1ad7462007-05-10 22:23:19 -07001341config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001342 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001343 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001344 default y
1345 help
1346 Enable the eventfd() system call that allows to receive both
1347 kernel notification (ie. KAIO) or userspace notifications.
1348
1349 If unsure, say Y.
1350
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001352 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 default y
1354 depends on MMU
1355 help
1356 The shmem is an internal filesystem used to manage shared memory.
1357 It is backed by swap and manages resource limits. It is also exported
1358 to userspace as tmpfs if TMPFS is enabled. Disabling this
1359 option replaces shmem and tmpfs with the much simpler ramfs code,
1360 which may be appropriate on small systems without swap.
1361
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001362config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001363 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001364 default y
1365 help
1366 This option enables POSIX asynchronous I/O which may by used
1367 by some high performance threaded applications. Disabling
1368 this option saves about 7k.
1369
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001370config EMBEDDED
1371 bool "Embedded system"
1372 select EXPERT
1373 help
1374 This option should be enabled if compiling the kernel for
1375 an embedded system so certain expert options are available
1376 for configuration.
1377
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001378config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001379 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001380 help
1381 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001382
Peter Zijlstra906010b2009-09-21 16:08:49 +02001383config PERF_USE_VMALLOC
1384 bool
1385 help
1386 See tools/perf/design.txt for details
1387
Ingo Molnar57c0c152009-09-21 12:20:38 +02001388menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001389
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001390config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001391 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001392 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001393 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001394 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001395 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001396 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001397 Enable kernel support for various performance events provided
1398 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001399
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001400 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001401 use of generic tracepoints.
1402
1403 Most modern CPUs support performance events via performance
1404 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001405 types of hw events: such as instructions executed, cachemisses
1406 suffered, or branches mis-predicted - without slowing down the
1407 kernel or applications. These registers can also trigger interrupts
1408 when a threshold number of events have passed - and can thus be
1409 used to profile the code that runs on that CPU.
1410
Ingo Molnar57c0c152009-09-21 12:20:38 +02001411 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001412 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001413 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001414 provides per task and per CPU counters, and it provides event
1415 capabilities on top of those.
1416
1417 Say Y if unsure.
1418
Peter Zijlstra906010b2009-09-21 16:08:49 +02001419config DEBUG_PERF_USE_VMALLOC
1420 default n
1421 bool "Debug: use vmalloc to back perf mmap() buffers"
1422 depends on PERF_EVENTS && DEBUG_KERNEL
1423 select PERF_USE_VMALLOC
1424 help
1425 Use vmalloc memory to back perf mmap() buffers.
1426
1427 Mostly useful for debugging the vmalloc code on platforms
1428 that don't require it.
1429
1430 Say N if unsure.
1431
Thomas Gleixner0793a612008-12-04 20:12:29 +01001432endmenu
1433
Christoph Lameterf8891e52006-06-30 01:55:45 -07001434config VM_EVENT_COUNTERS
1435 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001436 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001437 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001438 VM event counters are needed for event counts to be shown.
1439 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001440 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001441 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001442
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001443config PCI_QUIRKS
1444 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001445 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001446 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001447 help
1448 This enables workarounds for various PCI chipset
1449 bugs/quirks. Disable this only if your target machine is
1450 unaffected by PCI quirks.
1451
Christoph Lameter41ecc552007-05-09 02:32:44 -07001452config SLUB_DEBUG
1453 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001454 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001455 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001456 help
1457 SLUB has extensive debug support features. Disabling these can
1458 result in significant savings in code size. This also disables
1459 SLUB sysfs support. /sys/slab will not exist and there will be
1460 no support for cache validation etc.
1461
Randy Dunlapb943c462009-03-10 12:55:46 -07001462config COMPAT_BRK
1463 bool "Disable heap randomization"
1464 default y
1465 help
1466 Randomizing heap placement makes heap exploits harder, but it
1467 also breaks ancient binaries (including anything libc5 based).
1468 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001469 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001470 /proc/sys/kernel/randomize_va_space to 2.
1471
1472 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1473
Christoph Lameter81819f02007-05-06 14:49:36 -07001474choice
1475 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001476 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001477 help
1478 This option allows to select a slab allocator.
1479
1480config SLAB
1481 bool "SLAB"
1482 help
1483 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001484 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001485 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001486
1487config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001488 bool "SLUB (Unqueued Allocator)"
1489 help
1490 SLUB is a slab allocator that minimizes cache line usage
1491 instead of managing queues of cached objects (SLAB approach).
1492 Per cpu caching is realized using slabs of objects instead
1493 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001494 and has enhanced diagnostics. SLUB is the default choice for
1495 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001496
1497config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001498 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001499 bool "SLOB (Simple Allocator)"
1500 help
Matt Mackall37291452008-02-04 22:29:38 -08001501 SLOB replaces the stock allocator with a drastically simpler
1502 allocator. SLOB is generally more space efficient but
1503 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001504
1505endchoice
1506
Jie Zhangea637632009-12-14 18:00:02 -08001507config MMAP_ALLOW_UNINITIALIZED
1508 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001509 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001510 default n
1511 help
1512 Normally, and according to the Linux spec, anonymous memory obtained
1513 from mmap() has it's contents cleared before it is passed to
1514 userspace. Enabling this config option allows you to request that
1515 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1516 providing a huge performance boost. If this option is not enabled,
1517 then the flag will be ignored.
1518
1519 This is taken advantage of by uClibc's malloc(), and also by
1520 ELF-FDPIC binfmt's brk and stack allocator.
1521
1522 Because of the obvious security issues, this option should only be
1523 enabled on embedded devices where you control what is run in
1524 userspace. Since that isn't generally a problem on no-MMU systems,
1525 it is normally safe to say Y here.
1526
1527 See Documentation/nommu-mmap.txt for more information.
1528
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001529config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001530 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001531 help
1532 Say Y here to enable the extended profiling support mechanisms used
1533 by profilers such as OProfile.
1534
Ingo Molnar5f87f112008-07-23 14:15:22 +02001535#
1536# Place an empty function call at each tracepoint site. Can be
1537# dynamically changed for a probe function.
1538#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001539config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001540 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001541
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001542source "arch/Kconfig"
1543
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544endmenu # General setup
1545
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001546config HAVE_GENERIC_DMA_COHERENT
1547 bool
1548 default n
1549
Linus Torvalds158a9622008-01-02 13:04:48 -08001550config SLABINFO
1551 bool
1552 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001553 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001554 default y
1555
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001556config RT_MUTEXES
1557 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001558
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559config BASE_SMALL
1560 int
1561 default 0 if BASE_FULL
1562 default 1 if !BASE_FULL
1563
Jan Engelhardt66da5732007-07-15 23:39:29 -07001564menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 bool "Enable loadable module support"
1566 help
1567 Kernel modules are small pieces of compiled code which can
1568 be inserted in the running kernel, rather than being
1569 permanently built into the kernel. You use the "modprobe"
1570 tool to add (and sometimes remove) them. If you say Y here,
1571 many parts of the kernel can be built as modules (by
1572 answering M instead of Y where indicated): this is most
1573 useful for infrequently used options which are not required
1574 for booting. For more information, see the man pages for
1575 modprobe, lsmod, modinfo, insmod and rmmod.
1576
1577 If you say Y here, you will need to run "make
1578 modules_install" to put the modules under /lib/modules/
1579 where modprobe can find them (you may need to be root to do
1580 this).
1581
1582 If unsure, say Y.
1583
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001584if MODULES
1585
Linus Torvalds826e4502008-05-04 17:04:16 -07001586config MODULE_FORCE_LOAD
1587 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001588 default n
1589 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001590 Allow loading of modules without version information (ie. modprobe
1591 --force). Forced module loading sets the 'F' (forced) taint flag and
1592 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001593
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594config MODULE_UNLOAD
1595 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 help
1597 Without this option you will not be able to unload any
1598 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001599 anyway), which makes your kernel smaller, faster
1600 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001601
1602config MODULE_FORCE_UNLOAD
1603 bool "Forced module unloading"
1604 depends on MODULE_UNLOAD && EXPERIMENTAL
1605 help
1606 This option allows you to force a module to unload, even if the
1607 kernel believes it is unsafe: the kernel will remove the module
1608 without waiting for anyone to stop using it (using the -f option to
1609 rmmod). This is mainly for kernel developers and desperate users.
1610 If unsure, say N.
1611
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001613 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 help
1615 Usually, you have to use modules compiled with your kernel.
1616 Saying Y here makes it sometimes possible to use modules
1617 compiled for different kernels, by adding enough information
1618 to the modules to (hopefully) spot any changes which would
1619 make them incompatible with the kernel you are running. If
1620 unsure, say N.
1621
1622config MODULE_SRCVERSION_ALL
1623 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 help
1625 Modules which contain a MODULE_VERSION get an extra "srcversion"
1626 field inserted into their modinfo section, which contains a
1627 sum of the source files which made it. This helps maintainers
1628 see exactly which source was used to build a module (since
1629 others sometimes change the module source without updating
1630 the version). With this option, such a "srcversion" field
1631 will be created for all modules. If unsure, say N.
1632
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001633endif # MODULES
1634
Rusty Russell98a79d62008-12-13 21:19:41 +10301635config INIT_ALL_POSSIBLE
1636 bool
1637 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301638 Back when each arch used to define their own cpu_online_mask and
1639 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301640 with all 1s, and others with all 0s. When they were centralised,
1641 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001642 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301643
Linus Torvalds1da177e2005-04-16 15:20:36 -07001644config STOP_MACHINE
1645 bool
1646 default y
1647 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1648 help
1649 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001650
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001651source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001652
1653config PREEMPT_NOTIFIERS
1654 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001655
Steffen Klassert16295be2010-01-06 19:47:10 +11001656config PADATA
1657 depends on SMP
1658 bool
1659
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001660source "kernel/Kconfig.locks"