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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f72009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
Peter Oberparleiterb99b87f72009-06-17 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56 drivers that have been replaced by something else, and/or are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 Dunlap34ad92c22005-10-30 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. McKenney9fc52d82013-01-08 15:48:33 -0800456 depends on PREEMPT
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. McKenney9fc52d82013-01-08 15:48:33 -0800464 Select this option if you are unsure.
465
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700466config TINY_RCU
467 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700468 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700469 help
470 This option selects the RCU implementation that is
471 designed for UP systems from which real-time response
472 is not required. This option greatly reduces the
473 memory footprint of RCU.
474
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700475config TINY_PREEMPT_RCU
476 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700477 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700478 help
479 This option selects the RCU implementation that is designed
480 for real-time UP systems. This option greatly reduces the
481 memory footprint of RCU.
482
Mike Travisc903ff82009-01-15 12:28:29 -0800483endchoice
484
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700485config PREEMPT_RCU
486 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
487 help
488 This option enables preemptible-RCU code that is common between
489 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
490
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700491config RCU_STALL_COMMON
492 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
493 help
494 This option enables RCU CPU stall code that is common between
495 the TINY and TREE variants of RCU. The purpose is to allow
496 the tiny variants to disable RCU CPU stall warnings, while
497 making these warnings mandatory for the tree variants.
498
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100499config CONTEXT_TRACKING
500 bool
501
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200502config RCU_USER_QS
503 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100504 depends on HAVE_CONTEXT_TRACKING && SMP
505 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200506 help
507 This option sets hooks on kernel / userspace boundaries and
508 puts RCU in extended quiescent state when the CPU runs in
509 userspace. It means that when a CPU runs in userspace, it is
510 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700511 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200512
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200513 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100514 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700515 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200516
517 If unsure say N
518
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100519config CONTEXT_TRACKING_FORCE
520 bool "Force context tracking"
521 depends on CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200522 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100523 Probe on user/kernel boundaries by default in order to
524 test the features that rely on it such as userspace RCU extended
525 quiescent states.
526 This test is there for debugging until we have a real user like the
527 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200528
Mike Travisc903ff82009-01-15 12:28:29 -0800529config RCU_FANOUT
530 int "Tree-based hierarchical RCU fanout value"
531 range 2 64 if 64BIT
532 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700533 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800534 default 64 if 64BIT
535 default 32 if !64BIT
536 help
537 This option controls the fanout of hierarchical implementations
538 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700539 large numbers of CPUs. This value must be at least the fourth
540 root of NR_CPUS, which allows NR_CPUS to be insanely large.
541 The default value of RCU_FANOUT should be used for production
542 systems, but if you are stress-testing the RCU implementation
543 itself, small RCU_FANOUT values allow you to test large-system
544 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800545
546 Select a specific number if testing RCU itself.
547 Take the default if unsure.
548
Paul E. McKenney8932a632012-04-19 12:20:14 -0700549config RCU_FANOUT_LEAF
550 int "Tree-based hierarchical RCU leaf-level fanout value"
551 range 2 RCU_FANOUT if 64BIT
552 range 2 RCU_FANOUT if !64BIT
553 depends on TREE_RCU || TREE_PREEMPT_RCU
554 default 16
555 help
556 This option controls the leaf-level fanout of hierarchical
557 implementations of RCU, and allows trading off cache misses
558 against lock contention. Systems that synchronize their
559 scheduling-clock interrupts for energy-efficiency reasons will
560 want the default because the smaller leaf-level fanout keeps
561 lock contention levels acceptably low. Very large systems
562 (hundreds or thousands of CPUs) will instead want to set this
563 value to the maximum value possible in order to reduce the
564 number of cache misses incurred during RCU's grace-period
565 initialization. These systems tend to run CPU-bound, and thus
566 are not helped by synchronized interrupts, and thus tend to
567 skew them, which reduces lock contention enough that large
568 leaf-level fanouts work well.
569
570 Select a specific number if testing RCU itself.
571
572 Select the maximum permissible value for large systems.
573
574 Take the default if unsure.
575
Mike Travisc903ff82009-01-15 12:28:29 -0800576config RCU_FANOUT_EXACT
577 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700578 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800579 default n
580 help
581 This option forces use of the exact RCU_FANOUT value specified,
582 regardless of imbalances in the hierarchy. This is useful for
583 testing RCU itself, and might one day be useful on systems with
584 strong NUMA behavior.
585
586 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
587
588 Say N if unsure.
589
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800590config RCU_FAST_NO_HZ
591 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700592 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800593 default n
594 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700595 This option causes RCU to attempt to accelerate grace periods in
596 order to allow CPUs to enter dynticks-idle state more quickly.
597 On the other hand, this option increases the overhead of the
598 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800599
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700600 Say Y if energy efficiency is critically important, and you don't
601 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800602
603 Say N if you are unsure.
604
Mike Travisc903ff82009-01-15 12:28:29 -0800605config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700606 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800607 select DEBUG_FS
608 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700609 This option provides tracing for the TREE_RCU and
610 TREE_PREEMPT_RCU implementations, permitting Makefile to
611 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800612
Paul E. McKenney24278d12010-09-27 17:25:23 -0700613config RCU_BOOST
614 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800615 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700616 default n
617 help
618 This option boosts the priority of preempted RCU readers that
619 block the current preemptible RCU grace period for too long.
620 This option also prevents heavy loads from blocking RCU
621 callback invocation for all flavors of RCU.
622
623 Say Y here if you are working with real-time apps or heavy loads
624 Say N here if you are unsure.
625
626config RCU_BOOST_PRIO
627 int "Real-time priority to boost RCU readers to"
628 range 1 99
629 depends on RCU_BOOST
630 default 1
631 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700632 This option specifies the real-time priority to which long-term
633 preempted RCU readers are to be boosted. If you are working
634 with a real-time application that has one or more CPU-bound
635 threads running at a real-time priority level, you should set
636 RCU_BOOST_PRIO to a priority higher then the highest-priority
637 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
638 of 1 is appropriate in the common case, which is real-time
639 applications that do not have any CPU-bound threads.
640
641 Some real-time applications might not have a single real-time
642 thread that saturates a given CPU, but instead might have
643 multiple real-time threads that, taken together, fully utilize
644 that CPU. In this case, you should set RCU_BOOST_PRIO to
645 a priority higher than the lowest-priority thread that is
646 conspiring to prevent the CPU from running any non-real-time
647 tasks. For example, if one thread at priority 10 and another
648 thread at priority 5 are between themselves fully consuming
649 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
650 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700651
652 Specify the real-time priority, or take the default if unsure.
653
654config RCU_BOOST_DELAY
655 int "Milliseconds to delay boosting after RCU grace-period start"
656 range 0 3000
657 depends on RCU_BOOST
658 default 500
659 help
660 This option specifies the time to wait after the beginning of
661 a given grace period before priority-boosting preempted RCU
662 readers blocking that grace period. Note that any RCU reader
663 blocking an expedited RCU grace period is boosted immediately.
664
665 Accept the default if unsure.
666
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700667config RCU_NOCB_CPU
668 bool "Offload RCU callback processing from boot-selected CPUs"
669 depends on TREE_RCU || TREE_PREEMPT_RCU
670 default n
671 help
672 Use this option to reduce OS jitter for aggressive HPC or
673 real-time workloads. It can also be used to offload RCU
674 callback invocation to energy-efficient CPUs in battery-powered
675 asymmetric multiprocessors.
676
677 This option offloads callback invocation from the set of
678 CPUs specified at boot time by the rcu_nocbs parameter.
679 For each such CPU, a kthread ("rcuoN") will be created to
680 invoke callbacks, where the "N" is the CPU being offloaded.
681 Nothing prevents this kthread from running on the specified
682 CPUs, but (1) the kthreads may be preempted between each
683 callback, and (2) affinity or cgroups can be used to force
684 the kthreads to run on whatever set of CPUs is desired.
685
686 Say Y here if you want reduced OS jitter on selected CPUs.
687 Say N here if you are unsure.
688
Mike Travisc903ff82009-01-15 12:28:29 -0800689endmenu # "RCU Subsystem"
690
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700692 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 ---help---
694 This option enables the complete Linux kernel ".config" file
695 contents to be saved in the kernel. It provides documentation
696 of which kernel options are used in a running kernel or in an
697 on-disk kernel. This information can be extracted from the kernel
698 image file with the script scripts/extract-ikconfig and used as
699 input to rebuild the current kernel or to build another kernel.
700 It can also be extracted from a running kernel by reading
701 /proc/config.gz if enabled (below).
702
703config IKCONFIG_PROC
704 bool "Enable access to .config through /proc/config.gz"
705 depends on IKCONFIG && PROC_FS
706 ---help---
707 This option enables access to the kernel configuration file
708 through /proc/config.gz.
709
Alistair John Strachan794543a2007-05-08 00:31:15 -0700710config LOG_BUF_SHIFT
711 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
712 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700713 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700714 help
715 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700716 Examples:
717 17 => 128 KB
718 16 => 64 KB
719 15 => 32 KB
720 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700721 13 => 8 KB
722 12 => 4 KB
723
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800724#
725# Architectures with an unreliable sched_clock() should select this:
726#
727config HAVE_UNSTABLE_SCHED_CLOCK
728 bool
729
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200730#
731# For architectures that want to enable the support for NUMA-affine scheduler
732# balancing logic:
733#
734config ARCH_SUPPORTS_NUMA_BALANCING
735 bool
736
737# For architectures that (ab)use NUMA to represent different memory regions
738# all cpu-local but of different latencies, such as SuperH.
739#
740config ARCH_WANT_NUMA_VARIABLE_LOCALITY
741 bool
742
743#
744# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
745config ARCH_WANTS_PROT_NUMA_PROT_NONE
746 bool
747
748config ARCH_USES_NUMA_PROT_NONE
749 bool
750 default y
751 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
752 depends on NUMA_BALANCING
753
Mel Gorman1a687c22012-11-22 11:16:36 +0000754config NUMA_BALANCING_DEFAULT_ENABLED
755 bool "Automatically enable NUMA aware memory/task placement"
756 default y
757 depends on NUMA_BALANCING
758 help
759 If set, autonumic NUMA balancing will be enabled if running on a NUMA
760 machine.
761
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200762config NUMA_BALANCING
763 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200764 depends on ARCH_SUPPORTS_NUMA_BALANCING
765 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
766 depends on SMP && NUMA && MIGRATION
767 help
768 This option adds support for automatic NUMA aware memory/task placement.
769 The mechanism is quite primitive and is based on migrating memory when
770 it is references to the node the task is running on.
771
772 This system will be inactive on UMA systems.
773
Li Zefan23964d22009-01-15 13:50:58 -0800774menuconfig CGROUPS
775 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800776 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700777 help
Li Zefan23964d22009-01-15 13:50:58 -0800778 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800779 use with process control subsystems such as Cpusets, CFS, memory
780 controls or device isolation.
781 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800782 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800783 - Documentation/cgroups/ (features for grouping, isolation
784 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700785
786 Say N if unsure.
787
Li Zefan23964d22009-01-15 13:50:58 -0800788if CGROUPS
789
Paul Menage006cb992007-10-18 23:39:43 -0700790config CGROUP_DEBUG
791 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700792 default n
Paul Menage006cb992007-10-18 23:39:43 -0700793 help
794 This option enables a simple cgroup subsystem that
795 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800796 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700797
Li Zefan23964d22009-01-15 13:50:58 -0800798 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700799
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700800config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800801 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800802 help
803 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700804 cgroup.
805
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700806config CGROUP_DEVICE
807 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700808 help
809 Provides a cgroup implementing whitelists for devices which
810 a process in the cgroup can mknod or open.
811
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812config CPUSETS
813 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700815 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 allow dynamically partitioning a system into sets of CPUs and
817 Memory Nodes and assigning tasks to run only within those sets.
818 This is primarily useful on large SMP or NUMA systems.
819
820 Say N if unsure.
821
Li Zefan23964d22009-01-15 13:50:58 -0800822config PROC_PID_CPUSET
823 bool "Include legacy /proc/<pid>/cpuset file"
824 depends on CPUSETS
825 default y
826
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100827config CGROUP_CPUACCT
828 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100829 help
830 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800831 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100832
Pavel Emelianove552b662008-02-07 00:13:49 -0800833config RESOURCE_COUNTERS
834 bool "Resource counters"
835 help
836 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800837 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800838
Andrew Mortonc255a452012-07-31 16:43:02 -0700839config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800840 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700841 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700842 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800843 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700844 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100845 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800846
847 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700848 associated with each page of memory in the system. By this,
849 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
850 usage tracking struct at boot. Total amount of this is printed out
851 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800852
853 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700854 sure you need the memory resource controller. Even when you enable
855 this, you can set "cgroup_disable=memory" at your boot option to
856 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800857 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800858
Balbir Singhcf475ad2008-04-29 01:00:16 -0700859 This config option also selects MM_OWNER config option, which
860 could in turn add some fork/exit overhead.
861
Andrew Mortonc255a452012-07-31 16:43:02 -0700862config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700863 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700864 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800865 help
866 Add swap management feature to memory resource controller. When you
867 enable this, you can limit mem+swap usage per cgroup. In other words,
868 when you disable this, memory resource controller has no cares to
869 usage of swap...a process can exhaust all of the swap. This extension
870 is useful when you want to avoid exhaustion swap but this itself
871 adds more overheads and consumes memory for remembering information.
872 Especially if you use 32bit system or small memory system, please
873 be careful about enabling this. When memory resource controller
874 is disabled by boot option, this will be automatically disabled and
875 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700876 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700877 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
878 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700879config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800880 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700881 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800882 default y
883 help
884 Memory Resource Controller Swap Extension comes with its price in
885 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700886 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800887 and let the user enable it by swapaccount boot command line
888 parameter should have this option unselected.
889 For those who want to have the feature enabled by default should
890 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700891 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700892config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000893 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700894 depends on MEMCG && EXPERIMENTAL
Glauber Costa510fc4e2012-12-18 14:21:47 -0800895 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000896 help
897 The Kernel Memory extension for Memory Resource Controller can limit
898 the amount of memory used by kernel objects in the system. Those are
899 fundamentally different from the entities handled by the standard
900 Memory Controller, which are page-based, and can be swapped. Users of
901 the kmem extension can use it to guarantee that no group of processes
902 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800903
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700904config CGROUP_HUGETLB
905 bool "HugeTLB Resource Controller for Control Groups"
906 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
907 default n
908 help
909 Provides a cgroup Resource Controller for HugeTLB pages.
910 When you enable this, you can put a per cgroup limit on HugeTLB usage.
911 The limit is enforced during page fault. Since HugeTLB doesn't
912 support page reclaim, enforcing the limit at page fault time implies
913 that, the application will get SIGBUS signal if it tries to access
914 HugeTLB pages beyond its limit. This requires the application to know
915 beforehand how much HugeTLB pages it would require for its use. The
916 control group is tracked in the third page lru pointer. This means
917 that we cannot use the controller with huge page less than 3 pages.
918
Stephane Eraniane5d13672011-02-14 11:20:01 +0200919config CGROUP_PERF
920 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
921 depends on PERF_EVENTS && CGROUPS
922 help
923 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800924 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200925 designated cpu.
926
927 Say N if unsure.
928
Dhaval Giani7c941432010-01-20 13:26:18 +0100929menuconfig CGROUP_SCHED
930 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100931 default n
932 help
933 This feature lets CPU scheduler recognize task groups and control CPU
934 bandwidth allocation to such task groups. It uses cgroups to group
935 tasks.
936
937if CGROUP_SCHED
938config FAIR_GROUP_SCHED
939 bool "Group scheduling for SCHED_OTHER"
940 depends on CGROUP_SCHED
941 default CGROUP_SCHED
942
Paul Turnerab84d312011-07-21 09:43:28 -0700943config CFS_BANDWIDTH
944 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
945 depends on EXPERIMENTAL
946 depends on FAIR_GROUP_SCHED
947 default n
948 help
949 This option allows users to define CPU bandwidth rates (limits) for
950 tasks running within the fair group scheduler. Groups with no limit
951 set are considered to be unconstrained and will run with no
952 restriction.
953 See tip/Documentation/scheduler/sched-bwc.txt for more information.
954
Dhaval Giani7c941432010-01-20 13:26:18 +0100955config RT_GROUP_SCHED
956 bool "Group scheduling for SCHED_RR/FIFO"
957 depends on EXPERIMENTAL
958 depends on CGROUP_SCHED
959 default n
960 help
961 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800962 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100963 schedule realtime tasks for non-root users until you allocate
964 realtime bandwidth for them.
965 See Documentation/scheduler/sched-rt-group.txt for more information.
966
967endif #CGROUP_SCHED
968
Vivek Goyalafc24d42010-04-26 19:27:56 +0200969config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800970 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700971 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200972 default n
973 ---help---
974 Generic block IO controller cgroup interface. This is the common
975 cgroup interface which should be used by various IO controlling
976 policies.
977
978 Currently, CFQ IO scheduler uses it to recognize task groups and
979 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400980 to such task groups. It is also used by bio throttling logic in
981 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200982
983 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400984 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000985 enabling proportional weight division of disk bandwidth in CFQ, set
986 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000987 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200988
989 See Documentation/cgroups/blkio-controller.txt for more information.
990
991config DEBUG_BLK_CGROUP
992 bool "Enable Block IO controller debugging"
993 depends on BLK_CGROUP
994 default n
995 ---help---
996 Enable some debugging help. Currently it exports additional stat
997 files in a cgroup which can be useful for debugging.
998
Li Zefan23964d22009-01-15 13:50:58 -0800999endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001000
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001001config CHECKPOINT_RESTORE
1002 bool "Checkpoint/restore support" if EXPERT
1003 default n
1004 help
1005 Enables additional kernel features in a sake of checkpoint/restore.
1006 In particular it adds auxiliary prctl codes to setup process text,
1007 data and heap segment sizes, and a few additional /proc filesystem
1008 entries.
1009
1010 If unsure, say N here.
1011
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001012menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001013 bool "Namespaces support" if EXPERT
1014 default !EXPERT
Pavel Emelyanovc5289a692008-02-08 04:18:19 -08001015 help
1016 Provides the way to make tasks work with different objects using
1017 the same id. For example same IPC id may refer to different objects
1018 or same user id or pid may refer to different tasks when used in
1019 different namespaces.
1020
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001021if NAMESPACES
1022
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001023config UTS_NS
1024 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001025 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001026 help
1027 In this namespace tasks see different info provided with the
1028 uname() system call
1029
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001030config IPC_NS
1031 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001032 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001033 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001034 help
1035 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001036 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001037
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001038config USER_NS
1039 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001040 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001041 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001042 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001043
Eric W. Biederman5673a942011-11-17 10:23:55 -08001044 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001045 help
1046 This allows containers, i.e. vservers, to use user namespaces
1047 to provide different user info for different servers.
1048 If unsure, say N.
1049
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001050config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001051 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001052 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001053 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001054 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001055 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001056 pid namespaces. This is a building block of containers.
1057
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001058config NET_NS
1059 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001060 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001061 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001062 help
1063 Allow user space to create what appear to be multiple instances
1064 of the network stack.
1065
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001066endif # NAMESPACES
1067
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001068config UIDGID_CONVERTED
1069 # True if all of the selected software conmponents are known
1070 # to have uid_t and gid_t converted to kuid_t and kgid_t
1071 # where appropriate and are otherwise safe to use with
1072 # the user namespace.
1073 bool
1074 default y
1075
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001076 # Networking
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001077 depends on NET_9P = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001078
1079 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001080 depends on 9P_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001081 depends on AFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001082 depends on CEPH_FS = n
1083 depends on CIFS = n
1084 depends on CODA_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001085 depends on GFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001086 depends on NCP_FS = n
1087 depends on NFSD = n
1088 depends on NFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001089 depends on OCFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001090 depends on XFS_FS = n
1091
Eric W. Biederman5673a942011-11-17 10:23:55 -08001092config UIDGID_STRICT_TYPE_CHECKS
1093 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001094 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001095 default n
1096 help
1097 While the nececessary conversions are being added to all subsystems this option allows
1098 the code to continue to build for unconverted subsystems.
1099
1100 Say Y here if you want the strict type checking enabled
1101
Mike Galbraith5091faa2010-11-30 14:18:03 +01001102config SCHED_AUTOGROUP
1103 bool "Automatic process group scheduling"
1104 select EVENTFD
1105 select CGROUPS
1106 select CGROUP_SCHED
1107 select FAIR_GROUP_SCHED
1108 help
1109 This option optimizes the scheduler for common desktop workloads by
1110 automatically creating and populating task groups. This separation
1111 of workloads isolates aggressive CPU burners (like build jobs) from
1112 desktop applications. Task group autogeneration is currently based
1113 upon task session.
1114
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001115config MM_OWNER
1116 bool
1117
1118config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001119 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001120 depends on SYSFS
1121 default n
1122 help
1123 This option adds code that switches the layout of the "block" class
1124 devices, to not show up in /sys/class/block/, but only in
1125 /sys/block/.
1126
1127 This switch is only active when the sysfs.deprecated=1 boot option is
1128 passed or the SYSFS_DEPRECATED_V2 option is set.
1129
1130 This option allows new kernels to run on old distributions and tools,
1131 which might get confused by /sys/class/block/. Since 2007/2008 all
1132 major distributions and tools handle this just fine.
1133
1134 Recent distributions and userspace tools after 2009/2010 depend on
1135 the existence of /sys/class/block/, and will not work with this
1136 option enabled.
1137
1138 Only if you are using a new kernel on an old distribution, you might
1139 need to say Y here.
1140
1141config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001142 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001143 default n
1144 depends on SYSFS
1145 depends on SYSFS_DEPRECATED
1146 help
1147 Enable deprecated sysfs by default.
1148
1149 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1150 option.
1151
1152 Only if you are using a new kernel on an old distribution, you might
1153 need to say Y here. Even then, odds are you would not need it
1154 enabled, you can always pass the boot option if absolutely necessary.
1155
1156config RELAY
1157 bool "Kernel->user space relay support (formerly relayfs)"
1158 help
1159 This option enables support for relay interface support in
1160 certain file systems (such as debugfs).
1161 It is designed to provide an efficient mechanism for tools and
1162 facilities to relay large amounts of data from kernel space to
1163 user space.
1164
1165 If unsure, say N.
1166
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001167config BLK_DEV_INITRD
1168 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1169 depends on BROKEN || !FRV
1170 help
1171 The initial RAM filesystem is a ramfs which is loaded by the
1172 boot loader (loadlin or lilo) and that is mounted as root
1173 before the normal boot procedure. It is typically used to
1174 load modules needed to mount the "real" root file system,
1175 etc. See <file:Documentation/initrd.txt> for details.
1176
1177 If RAM disk support (BLK_DEV_RAM) is also included, this
1178 also enables initial RAM disk (initrd) support and adds
1179 15 Kbytes (more on some other architectures) to the kernel size.
1180
1181 If unsure say Y.
1182
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001183if BLK_DEV_INITRD
1184
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001185source "usr/Kconfig"
1186
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001187endif
1188
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001189config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001190 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001191 help
1192 Enabling this option will pass "-Os" instead of "-O2" to gcc
1193 resulting in a smaller kernel.
1194
jkacur775a7222008-07-16 00:31:16 +02001195 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001196
Randy Dunlap08470622006-09-30 23:28:13 -07001197config SYSCTL
1198 bool
1199
Randy Dunlapb943c462009-03-10 12:55:46 -07001200config ANON_INODES
1201 bool
1202
David Rientjes6a108a12011-01-20 14:44:16 -08001203menuconfig EXPERT
1204 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001205 # Unhide debug options, to make the on-by-default options visible
1206 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 help
1208 This option allows certain base kernel options and settings
1209 to be disabled or tweaked. This is for specialized
1210 environments which can tolerate a "non-standard" kernel.
1211 Only use this if you really know what you are doing.
1212
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001213config HAVE_UID16
1214 bool
1215
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001216config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001217 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001218 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001219 default y
1220 help
1221 This enables the legacy 16-bit UID syscall wrappers.
1222
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001223config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001224 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001225 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001226 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001227 select SYSCTL
1228 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001229 sys_sysctl uses binary paths that have been found challenging
1230 to properly maintain and use. The interface in /proc/sys
1231 using paths with ascii names is now the primary path to this
1232 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001233
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001234 Almost nothing using the binary sysctl interface so if you are
1235 trying to save some space it is probably safe to disable this,
1236 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001237
WANG Congc736de62011-11-02 13:39:25 -07001238 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001239
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001240config SYSCTL_EXCEPTION_TRACE
1241 bool
1242 help
1243 Enable support for /proc/sys/debug/exception-trace.
1244
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001246 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 default y
1248 help
1249 Say Y here to let the kernel print out symbolic crash information and
1250 symbolic stack backtraces. This increases the size of the kernel
1251 somewhat, as all symbols have to be loaded into the kernel image.
1252
1253config KALLSYMS_ALL
1254 bool "Include all symbols in kallsyms"
1255 depends on DEBUG_KERNEL && KALLSYMS
1256 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001257 Normally kallsyms only contains the symbols of functions for nicer
1258 OOPS messages and backtraces (i.e., symbols from the text and inittext
1259 sections). This is sufficient for most cases. And only in very rare
1260 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1261 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001263 This option makes sure that all symbols are loaded into the kernel
1264 image (i.e., symbols from all sections) in cost of increased kernel
1265 size (depending on the kernel configuration, it may be 300KiB or
1266 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001268 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001269
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001270config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001271 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001272
Matt Mackalld59745c2005-05-01 08:59:02 -07001273config PRINTK
1274 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001275 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001276 help
1277 This option enables normal printk support. Removing it
1278 eliminates most of the message strings from the kernel image
1279 and makes the kernel more or less silent. As this makes it
1280 very difficult to diagnose system problems, saying N here is
1281 strongly discouraged.
1282
Matt Mackallc8538a72005-05-01 08:59:01 -07001283config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001284 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001285 default y
1286 help
1287 Disabling this option eliminates support for BUG and WARN, reducing
1288 the size of your kernel image and potentially quietly ignoring
1289 numerous fatal conditions. You should only consider disabling this
1290 option for embedded systems with no facilities for reporting errors.
1291 Just say Y.
1292
Matt Mackall708e9a72006-01-08 01:05:25 -08001293config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001294 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001295 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001296 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001297 help
1298 Enable support for generating core dumps. Disabling saves about 4k.
1299
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001300
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001301config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001302 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001303 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001304 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001305 default y
1306 help
1307 This option allows to disable the internal PC-Speaker
1308 support, saving some memory.
1309
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001310config HAVE_PCSPKR_PLATFORM
1311 bool
1312
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313config BASE_FULL
1314 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001315 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 help
1317 Disabling this option reduces the size of miscellaneous core
1318 kernel data structures. This saves memory on small machines,
1319 but may reduce performance.
1320
1321config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001322 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001324 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 help
1326 Disabling this option will cause the kernel to be built without
1327 support for "fast userspace mutexes". The resulting kernel may not
1328 run glibc-based applications correctly.
1329
1330config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001331 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001333 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 help
1335 Disabling this option will cause the kernel to be built without
1336 support for epoll family of system calls.
1337
Davide Libenzifba2afa2007-05-10 22:23:13 -07001338config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001339 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001340 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001341 default y
1342 help
1343 Enable the signalfd() system call that allows to receive signals
1344 on a file descriptor.
1345
1346 If unsure, say Y.
1347
Davide Libenzib215e282007-05-10 22:23:16 -07001348config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001349 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001350 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001351 default y
1352 help
1353 Enable the timerfd() system call that allows to receive timer
1354 events on a file descriptor.
1355
1356 If unsure, say Y.
1357
Davide Libenzie1ad7462007-05-10 22:23:19 -07001358config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001359 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001360 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001361 default y
1362 help
1363 Enable the eventfd() system call that allows to receive both
1364 kernel notification (ie. KAIO) or userspace notifications.
1365
1366 If unsure, say Y.
1367
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001369 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 default y
1371 depends on MMU
1372 help
1373 The shmem is an internal filesystem used to manage shared memory.
1374 It is backed by swap and manages resource limits. It is also exported
1375 to userspace as tmpfs if TMPFS is enabled. Disabling this
1376 option replaces shmem and tmpfs with the much simpler ramfs code,
1377 which may be appropriate on small systems without swap.
1378
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001379config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001380 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001381 default y
1382 help
1383 This option enables POSIX asynchronous I/O which may by used
1384 by some high performance threaded applications. Disabling
1385 this option saves about 7k.
1386
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001387config EMBEDDED
1388 bool "Embedded system"
1389 select EXPERT
1390 help
1391 This option should be enabled if compiling the kernel for
1392 an embedded system so certain expert options are available
1393 for configuration.
1394
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001395config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001396 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001397 help
1398 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001399
Peter Zijlstra906010b2009-09-21 16:08:49 +02001400config PERF_USE_VMALLOC
1401 bool
1402 help
1403 See tools/perf/design.txt for details
1404
Ingo Molnar57c0c152009-09-21 12:20:38 +02001405menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001406
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001407config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001408 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001409 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001410 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001411 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001412 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001413 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001414 Enable kernel support for various performance events provided
1415 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001416
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001417 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001418 use of generic tracepoints.
1419
1420 Most modern CPUs support performance events via performance
1421 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001422 types of hw events: such as instructions executed, cachemisses
1423 suffered, or branches mis-predicted - without slowing down the
1424 kernel or applications. These registers can also trigger interrupts
1425 when a threshold number of events have passed - and can thus be
1426 used to profile the code that runs on that CPU.
1427
Ingo Molnar57c0c152009-09-21 12:20:38 +02001428 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001429 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001430 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001431 provides per task and per CPU counters, and it provides event
1432 capabilities on top of those.
1433
1434 Say Y if unsure.
1435
Peter Zijlstra906010b2009-09-21 16:08:49 +02001436config DEBUG_PERF_USE_VMALLOC
1437 default n
1438 bool "Debug: use vmalloc to back perf mmap() buffers"
1439 depends on PERF_EVENTS && DEBUG_KERNEL
1440 select PERF_USE_VMALLOC
1441 help
1442 Use vmalloc memory to back perf mmap() buffers.
1443
1444 Mostly useful for debugging the vmalloc code on platforms
1445 that don't require it.
1446
1447 Say N if unsure.
1448
Thomas Gleixner0793a612008-12-04 20:12:29 +01001449endmenu
1450
Christoph Lameterf8891e52006-06-30 01:55:45 -07001451config VM_EVENT_COUNTERS
1452 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001453 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001454 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001455 VM event counters are needed for event counts to be shown.
1456 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001457 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001458 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001459
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001460config PCI_QUIRKS
1461 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001462 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001463 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001464 help
1465 This enables workarounds for various PCI chipset
1466 bugs/quirks. Disable this only if your target machine is
1467 unaffected by PCI quirks.
1468
Christoph Lameter41ecc552007-05-09 02:32:44 -07001469config SLUB_DEBUG
1470 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001471 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001472 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001473 help
1474 SLUB has extensive debug support features. Disabling these can
1475 result in significant savings in code size. This also disables
1476 SLUB sysfs support. /sys/slab will not exist and there will be
1477 no support for cache validation etc.
1478
Randy Dunlapb943c462009-03-10 12:55:46 -07001479config COMPAT_BRK
1480 bool "Disable heap randomization"
1481 default y
1482 help
1483 Randomizing heap placement makes heap exploits harder, but it
1484 also breaks ancient binaries (including anything libc5 based).
1485 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001486 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001487 /proc/sys/kernel/randomize_va_space to 2.
1488
1489 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1490
Christoph Lameter81819f02007-05-06 14:49:36 -07001491choice
1492 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001493 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001494 help
1495 This option allows to select a slab allocator.
1496
1497config SLAB
1498 bool "SLAB"
1499 help
1500 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001501 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001502 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001503
1504config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001505 bool "SLUB (Unqueued Allocator)"
1506 help
1507 SLUB is a slab allocator that minimizes cache line usage
1508 instead of managing queues of cached objects (SLAB approach).
1509 Per cpu caching is realized using slabs of objects instead
1510 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001511 and has enhanced diagnostics. SLUB is the default choice for
1512 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001513
1514config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001515 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001516 bool "SLOB (Simple Allocator)"
1517 help
Matt Mackall37291452008-02-04 22:29:38 -08001518 SLOB replaces the stock allocator with a drastically simpler
1519 allocator. SLOB is generally more space efficient but
1520 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001521
1522endchoice
1523
Jie Zhangea637632009-12-14 18:00:02 -08001524config MMAP_ALLOW_UNINITIALIZED
1525 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001526 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001527 default n
1528 help
1529 Normally, and according to the Linux spec, anonymous memory obtained
1530 from mmap() has it's contents cleared before it is passed to
1531 userspace. Enabling this config option allows you to request that
1532 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1533 providing a huge performance boost. If this option is not enabled,
1534 then the flag will be ignored.
1535
1536 This is taken advantage of by uClibc's malloc(), and also by
1537 ELF-FDPIC binfmt's brk and stack allocator.
1538
1539 Because of the obvious security issues, this option should only be
1540 enabled on embedded devices where you control what is run in
1541 userspace. Since that isn't generally a problem on no-MMU systems,
1542 it is normally safe to say Y here.
1543
1544 See Documentation/nommu-mmap.txt for more information.
1545
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001546config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001547 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001548 help
1549 Say Y here to enable the extended profiling support mechanisms used
1550 by profilers such as OProfile.
1551
Ingo Molnar5f87f112008-07-23 14:15:22 +02001552#
1553# Place an empty function call at each tracepoint site. Can be
1554# dynamically changed for a probe function.
1555#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001556config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001557 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001558
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001559source "arch/Kconfig"
1560
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561endmenu # General setup
1562
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001563config HAVE_GENERIC_DMA_COHERENT
1564 bool
1565 default n
1566
Linus Torvalds158a9622008-01-02 13:04:48 -08001567config SLABINFO
1568 bool
1569 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001570 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001571 default y
1572
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001573config RT_MUTEXES
1574 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001575
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576config BASE_SMALL
1577 int
1578 default 0 if BASE_FULL
1579 default 1 if !BASE_FULL
1580
Jan Engelhardt66da5732007-07-15 23:39:29 -07001581menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 bool "Enable loadable module support"
1583 help
1584 Kernel modules are small pieces of compiled code which can
1585 be inserted in the running kernel, rather than being
1586 permanently built into the kernel. You use the "modprobe"
1587 tool to add (and sometimes remove) them. If you say Y here,
1588 many parts of the kernel can be built as modules (by
1589 answering M instead of Y where indicated): this is most
1590 useful for infrequently used options which are not required
1591 for booting. For more information, see the man pages for
1592 modprobe, lsmod, modinfo, insmod and rmmod.
1593
1594 If you say Y here, you will need to run "make
1595 modules_install" to put the modules under /lib/modules/
1596 where modprobe can find them (you may need to be root to do
1597 this).
1598
1599 If unsure, say Y.
1600
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001601if MODULES
1602
Linus Torvalds826e4502008-05-04 17:04:16 -07001603config MODULE_FORCE_LOAD
1604 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001605 default n
1606 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001607 Allow loading of modules without version information (ie. modprobe
1608 --force). Forced module loading sets the 'F' (forced) taint flag and
1609 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001610
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611config MODULE_UNLOAD
1612 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 help
1614 Without this option you will not be able to unload any
1615 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001616 anyway), which makes your kernel smaller, faster
1617 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618
1619config MODULE_FORCE_UNLOAD
1620 bool "Forced module unloading"
1621 depends on MODULE_UNLOAD && EXPERIMENTAL
1622 help
1623 This option allows you to force a module to unload, even if the
1624 kernel believes it is unsafe: the kernel will remove the module
1625 without waiting for anyone to stop using it (using the -f option to
1626 rmmod). This is mainly for kernel developers and desperate users.
1627 If unsure, say N.
1628
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001630 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 help
1632 Usually, you have to use modules compiled with your kernel.
1633 Saying Y here makes it sometimes possible to use modules
1634 compiled for different kernels, by adding enough information
1635 to the modules to (hopefully) spot any changes which would
1636 make them incompatible with the kernel you are running. If
1637 unsure, say N.
1638
1639config MODULE_SRCVERSION_ALL
1640 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641 help
1642 Modules which contain a MODULE_VERSION get an extra "srcversion"
1643 field inserted into their modinfo section, which contains a
1644 sum of the source files which made it. This helps maintainers
1645 see exactly which source was used to build a module (since
1646 others sometimes change the module source without updating
1647 the version). With this option, such a "srcversion" field
1648 will be created for all modules. If unsure, say N.
1649
Rusty Russell106a4ee2012-09-26 10:09:40 +01001650config MODULE_SIG
1651 bool "Module signature verification"
1652 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001653 select KEYS
1654 select CRYPTO
1655 select ASYMMETRIC_KEY_TYPE
1656 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1657 select PUBLIC_KEY_ALGO_RSA
1658 select ASN1
1659 select OID_REGISTRY
1660 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001661 help
1662 Check modules for valid signatures upon load: the signature
1663 is simply appended to the module. For more information see
1664 Documentation/module-signing.txt.
1665
David Howellsea0b6dc2012-09-26 10:09:50 +01001666 !!!WARNING!!! If you enable this option, you MUST make sure that the
1667 module DOES NOT get stripped after being signed. This includes the
1668 debuginfo strip done by some packagers (such as rpmbuild) and
1669 inclusion into an initramfs that wants the module size reduced.
1670
Rusty Russell106a4ee2012-09-26 10:09:40 +01001671config MODULE_SIG_FORCE
1672 bool "Require modules to be validly signed"
1673 depends on MODULE_SIG
1674 help
1675 Reject unsigned modules or signed modules for which we don't have a
1676 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001677
1678choice
1679 prompt "Which hash algorithm should modules be signed with?"
1680 depends on MODULE_SIG
1681 help
1682 This determines which sort of hashing algorithm will be used during
1683 signature generation. This algorithm _must_ be built into the kernel
1684 directly so that signature verification can take place. It is not
1685 possible to load a signed module containing the algorithm to check
1686 the signature on that module.
1687
1688config MODULE_SIG_SHA1
1689 bool "Sign modules with SHA-1"
1690 select CRYPTO_SHA1
1691
1692config MODULE_SIG_SHA224
1693 bool "Sign modules with SHA-224"
1694 select CRYPTO_SHA256
1695
1696config MODULE_SIG_SHA256
1697 bool "Sign modules with SHA-256"
1698 select CRYPTO_SHA256
1699
1700config MODULE_SIG_SHA384
1701 bool "Sign modules with SHA-384"
1702 select CRYPTO_SHA512
1703
1704config MODULE_SIG_SHA512
1705 bool "Sign modules with SHA-512"
1706 select CRYPTO_SHA512
1707
1708endchoice
1709
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001710endif # MODULES
1711
Rusty Russell98a79d62008-12-13 21:19:41 +10301712config INIT_ALL_POSSIBLE
1713 bool
1714 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301715 Back when each arch used to define their own cpu_online_mask and
1716 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301717 with all 1s, and others with all 0s. When they were centralised,
1718 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001719 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301720
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721config STOP_MACHINE
1722 bool
1723 default y
1724 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1725 help
1726 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001727
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001728source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001729
1730config PREEMPT_NOTIFIERS
1731 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001732
Steffen Klassert16295be2010-01-06 19:47:10 +11001733config PADATA
1734 depends on SMP
1735 bool
1736
Andi Kleen754b7b62012-10-04 17:11:27 -07001737# Can be selected by architectures with broken toolchains
1738# that get confused by correct const<->read_only section
1739# mappings
1740config BROKEN_RODATA
1741 bool
1742
David Howells4520c6a2012-09-21 23:31:13 +01001743config ASN1
1744 tristate
1745 help
1746 Build a simple ASN.1 grammar compiler that produces a bytecode output
1747 that can be interpreted by the ASN.1 stream decoder and used to
1748 inform it as to what tags are to be expected in a stream and what
1749 functions to call on what tags.
1750
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001751source "kernel/Kconfig.locks"