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Roman Zippel80daa562008-01-14 04:51:16 +01001config ARCH
2 string
3 option env="ARCH"
4
5config KERNELVERSION
6 string
7 option env="KERNELVERSION"
8
Roman Zippelface4372006-06-08 22:12:45 -07009config DEFCONFIG_LIST
10 string
Paolo 'Blaisorblade' Giarrussob2670eac2006-10-19 23:28:23 -070011 depends on !UML
Roman Zippelface4372006-06-08 22:12:45 -070012 option defconfig_list
13 default "/lib/modules/$UNAME_RELEASE/.config"
14 default "/etc/kernel-config"
15 default "/boot/config-$UNAME_RELEASE"
Sam Ravnborg73531902008-05-25 23:03:18 +020016 default "$ARCH_DEFCONFIG"
Roman Zippelface4372006-06-08 22:12:45 -070017 default "arch/$ARCH/defconfig"
18
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -070019config CONSTRUCTORS
20 bool
21 depends on !UML
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56 drivers that have been replaced by something else, and/or are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
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100489config CONTEXT_TRACKING
490 bool
491
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200492config RCU_USER_QS
493 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100494 depends on HAVE_CONTEXT_TRACKING && SMP
495 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200496 help
497 This option sets hooks on kernel / userspace boundaries and
498 puts RCU in extended quiescent state when the CPU runs in
499 userspace. It means that when a CPU runs in userspace, it is
500 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700501 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200502
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200503 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100504 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700505 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200506
507 If unsure say N
508
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100509config CONTEXT_TRACKING_FORCE
510 bool "Force context tracking"
511 depends on CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200512 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100513 Probe on user/kernel boundaries by default in order to
514 test the features that rely on it such as userspace RCU extended
515 quiescent states.
516 This test is there for debugging until we have a real user like the
517 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200518
Mike Travisc903ff82009-01-15 12:28:29 -0800519config RCU_FANOUT
520 int "Tree-based hierarchical RCU fanout value"
521 range 2 64 if 64BIT
522 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700523 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800524 default 64 if 64BIT
525 default 32 if !64BIT
526 help
527 This option controls the fanout of hierarchical implementations
528 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700529 large numbers of CPUs. This value must be at least the fourth
530 root of NR_CPUS, which allows NR_CPUS to be insanely large.
531 The default value of RCU_FANOUT should be used for production
532 systems, but if you are stress-testing the RCU implementation
533 itself, small RCU_FANOUT values allow you to test large-system
534 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800535
536 Select a specific number if testing RCU itself.
537 Take the default if unsure.
538
Paul E. McKenney8932a632012-04-19 12:20:14 -0700539config RCU_FANOUT_LEAF
540 int "Tree-based hierarchical RCU leaf-level fanout value"
541 range 2 RCU_FANOUT if 64BIT
542 range 2 RCU_FANOUT if !64BIT
543 depends on TREE_RCU || TREE_PREEMPT_RCU
544 default 16
545 help
546 This option controls the leaf-level fanout of hierarchical
547 implementations of RCU, and allows trading off cache misses
548 against lock contention. Systems that synchronize their
549 scheduling-clock interrupts for energy-efficiency reasons will
550 want the default because the smaller leaf-level fanout keeps
551 lock contention levels acceptably low. Very large systems
552 (hundreds or thousands of CPUs) will instead want to set this
553 value to the maximum value possible in order to reduce the
554 number of cache misses incurred during RCU's grace-period
555 initialization. These systems tend to run CPU-bound, and thus
556 are not helped by synchronized interrupts, and thus tend to
557 skew them, which reduces lock contention enough that large
558 leaf-level fanouts work well.
559
560 Select a specific number if testing RCU itself.
561
562 Select the maximum permissible value for large systems.
563
564 Take the default if unsure.
565
Mike Travisc903ff82009-01-15 12:28:29 -0800566config RCU_FANOUT_EXACT
567 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700568 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800569 default n
570 help
571 This option forces use of the exact RCU_FANOUT value specified,
572 regardless of imbalances in the hierarchy. This is useful for
573 testing RCU itself, and might one day be useful on systems with
574 strong NUMA behavior.
575
576 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
577
578 Say N if unsure.
579
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800580config RCU_FAST_NO_HZ
581 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700582 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800583 default n
584 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700585 This option causes RCU to attempt to accelerate grace periods in
586 order to allow CPUs to enter dynticks-idle state more quickly.
587 On the other hand, this option increases the overhead of the
588 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800589
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700590 Say Y if energy efficiency is critically important, and you don't
591 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800592
593 Say N if you are unsure.
594
Mike Travisc903ff82009-01-15 12:28:29 -0800595config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700596 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800597 select DEBUG_FS
598 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700599 This option provides tracing for the TREE_RCU and
600 TREE_PREEMPT_RCU implementations, permitting Makefile to
601 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800602
Paul E. McKenney24278d12010-09-27 17:25:23 -0700603config RCU_BOOST
604 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800605 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700606 default n
607 help
608 This option boosts the priority of preempted RCU readers that
609 block the current preemptible RCU grace period for too long.
610 This option also prevents heavy loads from blocking RCU
611 callback invocation for all flavors of RCU.
612
613 Say Y here if you are working with real-time apps or heavy loads
614 Say N here if you are unsure.
615
616config RCU_BOOST_PRIO
617 int "Real-time priority to boost RCU readers to"
618 range 1 99
619 depends on RCU_BOOST
620 default 1
621 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700622 This option specifies the real-time priority to which long-term
623 preempted RCU readers are to be boosted. If you are working
624 with a real-time application that has one or more CPU-bound
625 threads running at a real-time priority level, you should set
626 RCU_BOOST_PRIO to a priority higher then the highest-priority
627 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
628 of 1 is appropriate in the common case, which is real-time
629 applications that do not have any CPU-bound threads.
630
631 Some real-time applications might not have a single real-time
632 thread that saturates a given CPU, but instead might have
633 multiple real-time threads that, taken together, fully utilize
634 that CPU. In this case, you should set RCU_BOOST_PRIO to
635 a priority higher than the lowest-priority thread that is
636 conspiring to prevent the CPU from running any non-real-time
637 tasks. For example, if one thread at priority 10 and another
638 thread at priority 5 are between themselves fully consuming
639 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
640 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700641
642 Specify the real-time priority, or take the default if unsure.
643
644config RCU_BOOST_DELAY
645 int "Milliseconds to delay boosting after RCU grace-period start"
646 range 0 3000
647 depends on RCU_BOOST
648 default 500
649 help
650 This option specifies the time to wait after the beginning of
651 a given grace period before priority-boosting preempted RCU
652 readers blocking that grace period. Note that any RCU reader
653 blocking an expedited RCU grace period is boosted immediately.
654
655 Accept the default if unsure.
656
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700657config RCU_NOCB_CPU
658 bool "Offload RCU callback processing from boot-selected CPUs"
659 depends on TREE_RCU || TREE_PREEMPT_RCU
660 default n
661 help
662 Use this option to reduce OS jitter for aggressive HPC or
663 real-time workloads. It can also be used to offload RCU
664 callback invocation to energy-efficient CPUs in battery-powered
665 asymmetric multiprocessors.
666
667 This option offloads callback invocation from the set of
668 CPUs specified at boot time by the rcu_nocbs parameter.
669 For each such CPU, a kthread ("rcuoN") will be created to
670 invoke callbacks, where the "N" is the CPU being offloaded.
671 Nothing prevents this kthread from running on the specified
672 CPUs, but (1) the kthreads may be preempted between each
673 callback, and (2) affinity or cgroups can be used to force
674 the kthreads to run on whatever set of CPUs is desired.
675
676 Say Y here if you want reduced OS jitter on selected CPUs.
677 Say N here if you are unsure.
678
Mike Travisc903ff82009-01-15 12:28:29 -0800679endmenu # "RCU Subsystem"
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700682 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 ---help---
684 This option enables the complete Linux kernel ".config" file
685 contents to be saved in the kernel. It provides documentation
686 of which kernel options are used in a running kernel or in an
687 on-disk kernel. This information can be extracted from the kernel
688 image file with the script scripts/extract-ikconfig and used as
689 input to rebuild the current kernel or to build another kernel.
690 It can also be extracted from a running kernel by reading
691 /proc/config.gz if enabled (below).
692
693config IKCONFIG_PROC
694 bool "Enable access to .config through /proc/config.gz"
695 depends on IKCONFIG && PROC_FS
696 ---help---
697 This option enables access to the kernel configuration file
698 through /proc/config.gz.
699
Alistair John Strachan794543a2007-05-08 00:31:15 -0700700config LOG_BUF_SHIFT
701 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
702 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700703 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700704 help
705 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700706 Examples:
707 17 => 128 KB
708 16 => 64 KB
709 15 => 32 KB
710 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700711 13 => 8 KB
712 12 => 4 KB
713
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800714#
715# Architectures with an unreliable sched_clock() should select this:
716#
717config HAVE_UNSTABLE_SCHED_CLOCK
718 bool
719
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200720#
721# For architectures that want to enable the support for NUMA-affine scheduler
722# balancing logic:
723#
724config ARCH_SUPPORTS_NUMA_BALANCING
725 bool
726
727# For architectures that (ab)use NUMA to represent different memory regions
728# all cpu-local but of different latencies, such as SuperH.
729#
730config ARCH_WANT_NUMA_VARIABLE_LOCALITY
731 bool
732
733#
734# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
735config ARCH_WANTS_PROT_NUMA_PROT_NONE
736 bool
737
738config ARCH_USES_NUMA_PROT_NONE
739 bool
740 default y
741 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
742 depends on NUMA_BALANCING
743
Mel Gorman1a687c22012-11-22 11:16:36 +0000744config NUMA_BALANCING_DEFAULT_ENABLED
745 bool "Automatically enable NUMA aware memory/task placement"
746 default y
747 depends on NUMA_BALANCING
748 help
749 If set, autonumic NUMA balancing will be enabled if running on a NUMA
750 machine.
751
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200752config NUMA_BALANCING
753 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200754 depends on ARCH_SUPPORTS_NUMA_BALANCING
755 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
756 depends on SMP && NUMA && MIGRATION
757 help
758 This option adds support for automatic NUMA aware memory/task placement.
759 The mechanism is quite primitive and is based on migrating memory when
760 it is references to the node the task is running on.
761
762 This system will be inactive on UMA systems.
763
Li Zefan23964d22009-01-15 13:50:58 -0800764menuconfig CGROUPS
765 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800766 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700767 help
Li Zefan23964d22009-01-15 13:50:58 -0800768 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800769 use with process control subsystems such as Cpusets, CFS, memory
770 controls or device isolation.
771 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800772 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800773 - Documentation/cgroups/ (features for grouping, isolation
774 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700775
776 Say N if unsure.
777
Li Zefan23964d22009-01-15 13:50:58 -0800778if CGROUPS
779
Paul Menage006cb992007-10-18 23:39:43 -0700780config CGROUP_DEBUG
781 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700782 default n
Paul Menage006cb992007-10-18 23:39:43 -0700783 help
784 This option enables a simple cgroup subsystem that
785 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800786 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700787
Li Zefan23964d22009-01-15 13:50:58 -0800788 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700789
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700790config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800791 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800792 help
793 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700794 cgroup.
795
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700796config CGROUP_DEVICE
797 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700798 help
799 Provides a cgroup implementing whitelists for devices which
800 a process in the cgroup can mknod or open.
801
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802config CPUSETS
803 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700805 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 allow dynamically partitioning a system into sets of CPUs and
807 Memory Nodes and assigning tasks to run only within those sets.
808 This is primarily useful on large SMP or NUMA systems.
809
810 Say N if unsure.
811
Li Zefan23964d22009-01-15 13:50:58 -0800812config PROC_PID_CPUSET
813 bool "Include legacy /proc/<pid>/cpuset file"
814 depends on CPUSETS
815 default y
816
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100817config CGROUP_CPUACCT
818 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100819 help
820 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800821 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100822
Pavel Emelianove552b662008-02-07 00:13:49 -0800823config RESOURCE_COUNTERS
824 bool "Resource counters"
825 help
826 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800827 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800828
Andrew Mortonc255a452012-07-31 16:43:02 -0700829config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800830 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700831 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700832 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800833 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700834 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100835 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800836
837 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700838 associated with each page of memory in the system. By this,
839 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
840 usage tracking struct at boot. Total amount of this is printed out
841 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800842
843 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700844 sure you need the memory resource controller. Even when you enable
845 this, you can set "cgroup_disable=memory" at your boot option to
846 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800847 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800848
Balbir Singhcf475ad2008-04-29 01:00:16 -0700849 This config option also selects MM_OWNER config option, which
850 could in turn add some fork/exit overhead.
851
Andrew Mortonc255a452012-07-31 16:43:02 -0700852config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700853 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700854 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800855 help
856 Add swap management feature to memory resource controller. When you
857 enable this, you can limit mem+swap usage per cgroup. In other words,
858 when you disable this, memory resource controller has no cares to
859 usage of swap...a process can exhaust all of the swap. This extension
860 is useful when you want to avoid exhaustion swap but this itself
861 adds more overheads and consumes memory for remembering information.
862 Especially if you use 32bit system or small memory system, please
863 be careful about enabling this. When memory resource controller
864 is disabled by boot option, this will be automatically disabled and
865 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700866 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700867 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
868 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700869config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800870 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700871 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800872 default y
873 help
874 Memory Resource Controller Swap Extension comes with its price in
875 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700876 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800877 and let the user enable it by swapaccount boot command line
878 parameter should have this option unselected.
879 For those who want to have the feature enabled by default should
880 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700881 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700882config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000883 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700884 depends on MEMCG && EXPERIMENTAL
Glauber Costa510fc4e2012-12-18 14:21:47 -0800885 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000886 default n
887 help
888 The Kernel Memory extension for Memory Resource Controller can limit
889 the amount of memory used by kernel objects in the system. Those are
890 fundamentally different from the entities handled by the standard
891 Memory Controller, which are page-based, and can be swapped. Users of
892 the kmem extension can use it to guarantee that no group of processes
893 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800894
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700895config CGROUP_HUGETLB
896 bool "HugeTLB Resource Controller for Control Groups"
897 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
898 default n
899 help
900 Provides a cgroup Resource Controller for HugeTLB pages.
901 When you enable this, you can put a per cgroup limit on HugeTLB usage.
902 The limit is enforced during page fault. Since HugeTLB doesn't
903 support page reclaim, enforcing the limit at page fault time implies
904 that, the application will get SIGBUS signal if it tries to access
905 HugeTLB pages beyond its limit. This requires the application to know
906 beforehand how much HugeTLB pages it would require for its use. The
907 control group is tracked in the third page lru pointer. This means
908 that we cannot use the controller with huge page less than 3 pages.
909
Stephane Eraniane5d13672011-02-14 11:20:01 +0200910config CGROUP_PERF
911 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
912 depends on PERF_EVENTS && CGROUPS
913 help
914 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800915 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200916 designated cpu.
917
918 Say N if unsure.
919
Dhaval Giani7c941432010-01-20 13:26:18 +0100920menuconfig CGROUP_SCHED
921 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100922 default n
923 help
924 This feature lets CPU scheduler recognize task groups and control CPU
925 bandwidth allocation to such task groups. It uses cgroups to group
926 tasks.
927
928if CGROUP_SCHED
929config FAIR_GROUP_SCHED
930 bool "Group scheduling for SCHED_OTHER"
931 depends on CGROUP_SCHED
932 default CGROUP_SCHED
933
Paul Turnerab84d312011-07-21 09:43:28 -0700934config CFS_BANDWIDTH
935 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
936 depends on EXPERIMENTAL
937 depends on FAIR_GROUP_SCHED
938 default n
939 help
940 This option allows users to define CPU bandwidth rates (limits) for
941 tasks running within the fair group scheduler. Groups with no limit
942 set are considered to be unconstrained and will run with no
943 restriction.
944 See tip/Documentation/scheduler/sched-bwc.txt for more information.
945
Dhaval Giani7c941432010-01-20 13:26:18 +0100946config RT_GROUP_SCHED
947 bool "Group scheduling for SCHED_RR/FIFO"
948 depends on EXPERIMENTAL
949 depends on CGROUP_SCHED
950 default n
951 help
952 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800953 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100954 schedule realtime tasks for non-root users until you allocate
955 realtime bandwidth for them.
956 See Documentation/scheduler/sched-rt-group.txt for more information.
957
958endif #CGROUP_SCHED
959
Vivek Goyalafc24d42010-04-26 19:27:56 +0200960config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800961 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700962 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200963 default n
964 ---help---
965 Generic block IO controller cgroup interface. This is the common
966 cgroup interface which should be used by various IO controlling
967 policies.
968
969 Currently, CFQ IO scheduler uses it to recognize task groups and
970 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400971 to such task groups. It is also used by bio throttling logic in
972 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200973
974 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400975 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000976 enabling proportional weight division of disk bandwidth in CFQ, set
977 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000978 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200979
980 See Documentation/cgroups/blkio-controller.txt for more information.
981
982config DEBUG_BLK_CGROUP
983 bool "Enable Block IO controller debugging"
984 depends on BLK_CGROUP
985 default n
986 ---help---
987 Enable some debugging help. Currently it exports additional stat
988 files in a cgroup which can be useful for debugging.
989
Li Zefan23964d22009-01-15 13:50:58 -0800990endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800991
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800992config CHECKPOINT_RESTORE
993 bool "Checkpoint/restore support" if EXPERT
994 default n
995 help
996 Enables additional kernel features in a sake of checkpoint/restore.
997 In particular it adds auxiliary prctl codes to setup process text,
998 data and heap segment sizes, and a few additional /proc filesystem
999 entries.
1000
1001 If unsure, say N here.
1002
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001003menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001004 bool "Namespaces support" if EXPERT
1005 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001006 help
1007 Provides the way to make tasks work with different objects using
1008 the same id. For example same IPC id may refer to different objects
1009 or same user id or pid may refer to different tasks when used in
1010 different namespaces.
1011
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001012if NAMESPACES
1013
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001014config UTS_NS
1015 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001016 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001017 help
1018 In this namespace tasks see different info provided with the
1019 uname() system call
1020
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001021config IPC_NS
1022 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001023 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001024 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001025 help
1026 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001027 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001028
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001029config USER_NS
1030 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001031 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001032 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001033 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001034
Eric W. Biederman5673a942011-11-17 10:23:55 -08001035 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001036 help
1037 This allows containers, i.e. vservers, to use user namespaces
1038 to provide different user info for different servers.
1039 If unsure, say N.
1040
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001041config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001042 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001043 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001044 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001045 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001046 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001047 pid namespaces. This is a building block of containers.
1048
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001049config NET_NS
1050 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001051 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001052 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001053 help
1054 Allow user space to create what appear to be multiple instances
1055 of the network stack.
1056
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001057endif # NAMESPACES
1058
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001059config UIDGID_CONVERTED
1060 # True if all of the selected software conmponents are known
1061 # to have uid_t and gid_t converted to kuid_t and kgid_t
1062 # where appropriate and are otherwise safe to use with
1063 # the user namespace.
1064 bool
1065 default y
1066
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001067 # Networking
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001068 depends on NET_9P = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001069
1070 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001071 depends on 9P_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001072 depends on AFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001073 depends on CEPH_FS = n
1074 depends on CIFS = n
1075 depends on CODA_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001076 depends on GFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001077 depends on NCP_FS = n
1078 depends on NFSD = n
1079 depends on NFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001080 depends on OCFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001081 depends on XFS_FS = n
1082
Eric W. Biederman5673a942011-11-17 10:23:55 -08001083config UIDGID_STRICT_TYPE_CHECKS
1084 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001085 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001086 default n
1087 help
1088 While the nececessary conversions are being added to all subsystems this option allows
1089 the code to continue to build for unconverted subsystems.
1090
1091 Say Y here if you want the strict type checking enabled
1092
Mike Galbraith5091faa2010-11-30 14:18:03 +01001093config SCHED_AUTOGROUP
1094 bool "Automatic process group scheduling"
1095 select EVENTFD
1096 select CGROUPS
1097 select CGROUP_SCHED
1098 select FAIR_GROUP_SCHED
1099 help
1100 This option optimizes the scheduler for common desktop workloads by
1101 automatically creating and populating task groups. This separation
1102 of workloads isolates aggressive CPU burners (like build jobs) from
1103 desktop applications. Task group autogeneration is currently based
1104 upon task session.
1105
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001106config MM_OWNER
1107 bool
1108
1109config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001110 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001111 depends on SYSFS
1112 default n
1113 help
1114 This option adds code that switches the layout of the "block" class
1115 devices, to not show up in /sys/class/block/, but only in
1116 /sys/block/.
1117
1118 This switch is only active when the sysfs.deprecated=1 boot option is
1119 passed or the SYSFS_DEPRECATED_V2 option is set.
1120
1121 This option allows new kernels to run on old distributions and tools,
1122 which might get confused by /sys/class/block/. Since 2007/2008 all
1123 major distributions and tools handle this just fine.
1124
1125 Recent distributions and userspace tools after 2009/2010 depend on
1126 the existence of /sys/class/block/, and will not work with this
1127 option enabled.
1128
1129 Only if you are using a new kernel on an old distribution, you might
1130 need to say Y here.
1131
1132config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001133 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001134 default n
1135 depends on SYSFS
1136 depends on SYSFS_DEPRECATED
1137 help
1138 Enable deprecated sysfs by default.
1139
1140 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1141 option.
1142
1143 Only if you are using a new kernel on an old distribution, you might
1144 need to say Y here. Even then, odds are you would not need it
1145 enabled, you can always pass the boot option if absolutely necessary.
1146
1147config RELAY
1148 bool "Kernel->user space relay support (formerly relayfs)"
1149 help
1150 This option enables support for relay interface support in
1151 certain file systems (such as debugfs).
1152 It is designed to provide an efficient mechanism for tools and
1153 facilities to relay large amounts of data from kernel space to
1154 user space.
1155
1156 If unsure, say N.
1157
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001158config BLK_DEV_INITRD
1159 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1160 depends on BROKEN || !FRV
1161 help
1162 The initial RAM filesystem is a ramfs which is loaded by the
1163 boot loader (loadlin or lilo) and that is mounted as root
1164 before the normal boot procedure. It is typically used to
1165 load modules needed to mount the "real" root file system,
1166 etc. See <file:Documentation/initrd.txt> for details.
1167
1168 If RAM disk support (BLK_DEV_RAM) is also included, this
1169 also enables initial RAM disk (initrd) support and adds
1170 15 Kbytes (more on some other architectures) to the kernel size.
1171
1172 If unsure say Y.
1173
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001174if BLK_DEV_INITRD
1175
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001176source "usr/Kconfig"
1177
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001178endif
1179
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001180config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001181 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001182 help
1183 Enabling this option will pass "-Os" instead of "-O2" to gcc
1184 resulting in a smaller kernel.
1185
jkacur775a7222008-07-16 00:31:16 +02001186 If unsure, say Y.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001187
Randy Dunlap08470622006-09-30 23:28:13 -07001188config SYSCTL
1189 bool
1190
Randy Dunlapb943c462009-03-10 12:55:46 -07001191config ANON_INODES
1192 bool
1193
David Rientjes6a108a12011-01-20 14:44:16 -08001194menuconfig EXPERT
1195 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001196 # Unhide debug options, to make the on-by-default options visible
1197 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 help
1199 This option allows certain base kernel options and settings
1200 to be disabled or tweaked. This is for specialized
1201 environments which can tolerate a "non-standard" kernel.
1202 Only use this if you really know what you are doing.
1203
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001204config HAVE_UID16
1205 bool
1206
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001207config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001208 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001209 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001210 default y
1211 help
1212 This enables the legacy 16-bit UID syscall wrappers.
1213
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001214config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001215 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001216 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001217 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001218 select SYSCTL
1219 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001220 sys_sysctl uses binary paths that have been found challenging
1221 to properly maintain and use. The interface in /proc/sys
1222 using paths with ascii names is now the primary path to this
1223 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001224
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001225 Almost nothing using the binary sysctl interface so if you are
1226 trying to save some space it is probably safe to disable this,
1227 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001228
WANG Congc736de62011-11-02 13:39:25 -07001229 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001230
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001231config SYSCTL_EXCEPTION_TRACE
1232 bool
1233 help
1234 Enable support for /proc/sys/debug/exception-trace.
1235
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001237 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 default y
1239 help
1240 Say Y here to let the kernel print out symbolic crash information and
1241 symbolic stack backtraces. This increases the size of the kernel
1242 somewhat, as all symbols have to be loaded into the kernel image.
1243
1244config KALLSYMS_ALL
1245 bool "Include all symbols in kallsyms"
1246 depends on DEBUG_KERNEL && KALLSYMS
1247 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001248 Normally kallsyms only contains the symbols of functions for nicer
1249 OOPS messages and backtraces (i.e., symbols from the text and inittext
1250 sections). This is sufficient for most cases. And only in very rare
1251 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1252 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001254 This option makes sure that all symbols are loaded into the kernel
1255 image (i.e., symbols from all sections) in cost of increased kernel
1256 size (depending on the kernel configuration, it may be 300KiB or
1257 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001259 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001260
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001261config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001262 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001263
Matt Mackalld59745c2005-05-01 08:59:02 -07001264config PRINTK
1265 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001266 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001267 help
1268 This option enables normal printk support. Removing it
1269 eliminates most of the message strings from the kernel image
1270 and makes the kernel more or less silent. As this makes it
1271 very difficult to diagnose system problems, saying N here is
1272 strongly discouraged.
1273
Matt Mackallc8538a72005-05-01 08:59:01 -07001274config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001275 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001276 default y
1277 help
1278 Disabling this option eliminates support for BUG and WARN, reducing
1279 the size of your kernel image and potentially quietly ignoring
1280 numerous fatal conditions. You should only consider disabling this
1281 option for embedded systems with no facilities for reporting errors.
1282 Just say Y.
1283
Matt Mackall708e9a72006-01-08 01:05:25 -08001284config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001285 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001286 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001287 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001288 help
1289 Enable support for generating core dumps. Disabling saves about 4k.
1290
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001291
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001292config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001293 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001294 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001295 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001296 default y
1297 help
1298 This option allows to disable the internal PC-Speaker
1299 support, saving some memory.
1300
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001301config HAVE_PCSPKR_PLATFORM
1302 bool
1303
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304config BASE_FULL
1305 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001306 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 help
1308 Disabling this option reduces the size of miscellaneous core
1309 kernel data structures. This saves memory on small machines,
1310 but may reduce performance.
1311
1312config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001313 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001315 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 help
1317 Disabling this option will cause the kernel to be built without
1318 support for "fast userspace mutexes". The resulting kernel may not
1319 run glibc-based applications correctly.
1320
1321config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001322 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001324 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 help
1326 Disabling this option will cause the kernel to be built without
1327 support for epoll family of system calls.
1328
Davide Libenzifba2afa2007-05-10 22:23:13 -07001329config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001330 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001331 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001332 default y
1333 help
1334 Enable the signalfd() system call that allows to receive signals
1335 on a file descriptor.
1336
1337 If unsure, say Y.
1338
Davide Libenzib215e282007-05-10 22:23:16 -07001339config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001340 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001341 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001342 default y
1343 help
1344 Enable the timerfd() system call that allows to receive timer
1345 events on a file descriptor.
1346
1347 If unsure, say Y.
1348
Davide Libenzie1ad7462007-05-10 22:23:19 -07001349config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001350 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001351 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001352 default y
1353 help
1354 Enable the eventfd() system call that allows to receive both
1355 kernel notification (ie. KAIO) or userspace notifications.
1356
1357 If unsure, say Y.
1358
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001360 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 default y
1362 depends on MMU
1363 help
1364 The shmem is an internal filesystem used to manage shared memory.
1365 It is backed by swap and manages resource limits. It is also exported
1366 to userspace as tmpfs if TMPFS is enabled. Disabling this
1367 option replaces shmem and tmpfs with the much simpler ramfs code,
1368 which may be appropriate on small systems without swap.
1369
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001370config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001371 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001372 default y
1373 help
1374 This option enables POSIX asynchronous I/O which may by used
1375 by some high performance threaded applications. Disabling
1376 this option saves about 7k.
1377
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001378config EMBEDDED
1379 bool "Embedded system"
1380 select EXPERT
1381 help
1382 This option should be enabled if compiling the kernel for
1383 an embedded system so certain expert options are available
1384 for configuration.
1385
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001386config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001387 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001388 help
1389 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001390
Peter Zijlstra906010b2009-09-21 16:08:49 +02001391config PERF_USE_VMALLOC
1392 bool
1393 help
1394 See tools/perf/design.txt for details
1395
Ingo Molnar57c0c152009-09-21 12:20:38 +02001396menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001397
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001398config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001399 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001400 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001401 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001402 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001403 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001404 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001405 Enable kernel support for various performance events provided
1406 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001407
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001408 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001409 use of generic tracepoints.
1410
1411 Most modern CPUs support performance events via performance
1412 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001413 types of hw events: such as instructions executed, cachemisses
1414 suffered, or branches mis-predicted - without slowing down the
1415 kernel or applications. These registers can also trigger interrupts
1416 when a threshold number of events have passed - and can thus be
1417 used to profile the code that runs on that CPU.
1418
Ingo Molnar57c0c152009-09-21 12:20:38 +02001419 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001420 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001421 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001422 provides per task and per CPU counters, and it provides event
1423 capabilities on top of those.
1424
1425 Say Y if unsure.
1426
Peter Zijlstra906010b2009-09-21 16:08:49 +02001427config DEBUG_PERF_USE_VMALLOC
1428 default n
1429 bool "Debug: use vmalloc to back perf mmap() buffers"
1430 depends on PERF_EVENTS && DEBUG_KERNEL
1431 select PERF_USE_VMALLOC
1432 help
1433 Use vmalloc memory to back perf mmap() buffers.
1434
1435 Mostly useful for debugging the vmalloc code on platforms
1436 that don't require it.
1437
1438 Say N if unsure.
1439
Thomas Gleixner0793a612008-12-04 20:12:29 +01001440endmenu
1441
Christoph Lameterf8891e52006-06-30 01:55:45 -07001442config VM_EVENT_COUNTERS
1443 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001444 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001445 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001446 VM event counters are needed for event counts to be shown.
1447 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001448 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001449 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001450
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001451config PCI_QUIRKS
1452 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001453 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001454 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001455 help
1456 This enables workarounds for various PCI chipset
1457 bugs/quirks. Disable this only if your target machine is
1458 unaffected by PCI quirks.
1459
Christoph Lameter41ecc552007-05-09 02:32:44 -07001460config SLUB_DEBUG
1461 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001462 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001463 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001464 help
1465 SLUB has extensive debug support features. Disabling these can
1466 result in significant savings in code size. This also disables
1467 SLUB sysfs support. /sys/slab will not exist and there will be
1468 no support for cache validation etc.
1469
Randy Dunlapb943c462009-03-10 12:55:46 -07001470config COMPAT_BRK
1471 bool "Disable heap randomization"
1472 default y
1473 help
1474 Randomizing heap placement makes heap exploits harder, but it
1475 also breaks ancient binaries (including anything libc5 based).
1476 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001477 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001478 /proc/sys/kernel/randomize_va_space to 2.
1479
1480 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1481
Christoph Lameter81819f02007-05-06 14:49:36 -07001482choice
1483 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001484 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001485 help
1486 This option allows to select a slab allocator.
1487
1488config SLAB
1489 bool "SLAB"
1490 help
1491 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001492 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001493 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001494
1495config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001496 bool "SLUB (Unqueued Allocator)"
1497 help
1498 SLUB is a slab allocator that minimizes cache line usage
1499 instead of managing queues of cached objects (SLAB approach).
1500 Per cpu caching is realized using slabs of objects instead
1501 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001502 and has enhanced diagnostics. SLUB is the default choice for
1503 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001504
1505config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001506 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001507 bool "SLOB (Simple Allocator)"
1508 help
Matt Mackall37291452008-02-04 22:29:38 -08001509 SLOB replaces the stock allocator with a drastically simpler
1510 allocator. SLOB is generally more space efficient but
1511 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001512
1513endchoice
1514
Jie Zhangea637632009-12-14 18:00:02 -08001515config MMAP_ALLOW_UNINITIALIZED
1516 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001517 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001518 default n
1519 help
1520 Normally, and according to the Linux spec, anonymous memory obtained
1521 from mmap() has it's contents cleared before it is passed to
1522 userspace. Enabling this config option allows you to request that
1523 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1524 providing a huge performance boost. If this option is not enabled,
1525 then the flag will be ignored.
1526
1527 This is taken advantage of by uClibc's malloc(), and also by
1528 ELF-FDPIC binfmt's brk and stack allocator.
1529
1530 Because of the obvious security issues, this option should only be
1531 enabled on embedded devices where you control what is run in
1532 userspace. Since that isn't generally a problem on no-MMU systems,
1533 it is normally safe to say Y here.
1534
1535 See Documentation/nommu-mmap.txt for more information.
1536
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001537config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001538 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001539 help
1540 Say Y here to enable the extended profiling support mechanisms used
1541 by profilers such as OProfile.
1542
Ingo Molnar5f87f112008-07-23 14:15:22 +02001543#
1544# Place an empty function call at each tracepoint site. Can be
1545# dynamically changed for a probe function.
1546#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001547config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001548 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001549
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001550source "arch/Kconfig"
1551
Linus Torvalds1da177e2005-04-16 15:20:36 -07001552endmenu # General setup
1553
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001554config HAVE_GENERIC_DMA_COHERENT
1555 bool
1556 default n
1557
Linus Torvalds158a9622008-01-02 13:04:48 -08001558config SLABINFO
1559 bool
1560 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001561 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001562 default y
1563
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001564config RT_MUTEXES
1565 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001566
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567config BASE_SMALL
1568 int
1569 default 0 if BASE_FULL
1570 default 1 if !BASE_FULL
1571
Jan Engelhardt66da5732007-07-15 23:39:29 -07001572menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573 bool "Enable loadable module support"
1574 help
1575 Kernel modules are small pieces of compiled code which can
1576 be inserted in the running kernel, rather than being
1577 permanently built into the kernel. You use the "modprobe"
1578 tool to add (and sometimes remove) them. If you say Y here,
1579 many parts of the kernel can be built as modules (by
1580 answering M instead of Y where indicated): this is most
1581 useful for infrequently used options which are not required
1582 for booting. For more information, see the man pages for
1583 modprobe, lsmod, modinfo, insmod and rmmod.
1584
1585 If you say Y here, you will need to run "make
1586 modules_install" to put the modules under /lib/modules/
1587 where modprobe can find them (you may need to be root to do
1588 this).
1589
1590 If unsure, say Y.
1591
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001592if MODULES
1593
Linus Torvalds826e4502008-05-04 17:04:16 -07001594config MODULE_FORCE_LOAD
1595 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001596 default n
1597 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001598 Allow loading of modules without version information (ie. modprobe
1599 --force). Forced module loading sets the 'F' (forced) taint flag and
1600 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001601
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602config MODULE_UNLOAD
1603 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 help
1605 Without this option you will not be able to unload any
1606 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001607 anyway), which makes your kernel smaller, faster
1608 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609
1610config MODULE_FORCE_UNLOAD
1611 bool "Forced module unloading"
1612 depends on MODULE_UNLOAD && EXPERIMENTAL
1613 help
1614 This option allows you to force a module to unload, even if the
1615 kernel believes it is unsafe: the kernel will remove the module
1616 without waiting for anyone to stop using it (using the -f option to
1617 rmmod). This is mainly for kernel developers and desperate users.
1618 If unsure, say N.
1619
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001621 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 help
1623 Usually, you have to use modules compiled with your kernel.
1624 Saying Y here makes it sometimes possible to use modules
1625 compiled for different kernels, by adding enough information
1626 to the modules to (hopefully) spot any changes which would
1627 make them incompatible with the kernel you are running. If
1628 unsure, say N.
1629
1630config MODULE_SRCVERSION_ALL
1631 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 help
1633 Modules which contain a MODULE_VERSION get an extra "srcversion"
1634 field inserted into their modinfo section, which contains a
1635 sum of the source files which made it. This helps maintainers
1636 see exactly which source was used to build a module (since
1637 others sometimes change the module source without updating
1638 the version). With this option, such a "srcversion" field
1639 will be created for all modules. If unsure, say N.
1640
Rusty Russell106a4ee2012-09-26 10:09:40 +01001641config MODULE_SIG
1642 bool "Module signature verification"
1643 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001644 select KEYS
1645 select CRYPTO
1646 select ASYMMETRIC_KEY_TYPE
1647 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1648 select PUBLIC_KEY_ALGO_RSA
1649 select ASN1
1650 select OID_REGISTRY
1651 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001652 help
1653 Check modules for valid signatures upon load: the signature
1654 is simply appended to the module. For more information see
1655 Documentation/module-signing.txt.
1656
David Howellsea0b6dc2012-09-26 10:09:50 +01001657 !!!WARNING!!! If you enable this option, you MUST make sure that the
1658 module DOES NOT get stripped after being signed. This includes the
1659 debuginfo strip done by some packagers (such as rpmbuild) and
1660 inclusion into an initramfs that wants the module size reduced.
1661
Rusty Russell106a4ee2012-09-26 10:09:40 +01001662config MODULE_SIG_FORCE
1663 bool "Require modules to be validly signed"
1664 depends on MODULE_SIG
1665 help
1666 Reject unsigned modules or signed modules for which we don't have a
1667 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001668
1669choice
1670 prompt "Which hash algorithm should modules be signed with?"
1671 depends on MODULE_SIG
1672 help
1673 This determines which sort of hashing algorithm will be used during
1674 signature generation. This algorithm _must_ be built into the kernel
1675 directly so that signature verification can take place. It is not
1676 possible to load a signed module containing the algorithm to check
1677 the signature on that module.
1678
1679config MODULE_SIG_SHA1
1680 bool "Sign modules with SHA-1"
1681 select CRYPTO_SHA1
1682
1683config MODULE_SIG_SHA224
1684 bool "Sign modules with SHA-224"
1685 select CRYPTO_SHA256
1686
1687config MODULE_SIG_SHA256
1688 bool "Sign modules with SHA-256"
1689 select CRYPTO_SHA256
1690
1691config MODULE_SIG_SHA384
1692 bool "Sign modules with SHA-384"
1693 select CRYPTO_SHA512
1694
1695config MODULE_SIG_SHA512
1696 bool "Sign modules with SHA-512"
1697 select CRYPTO_SHA512
1698
1699endchoice
1700
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001701endif # MODULES
1702
Rusty Russell98a79d62008-12-13 21:19:41 +10301703config INIT_ALL_POSSIBLE
1704 bool
1705 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301706 Back when each arch used to define their own cpu_online_mask and
1707 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301708 with all 1s, and others with all 0s. When they were centralised,
1709 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001710 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301711
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712config STOP_MACHINE
1713 bool
1714 default y
1715 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1716 help
1717 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001718
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001719source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001720
1721config PREEMPT_NOTIFIERS
1722 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001723
Steffen Klassert16295be2010-01-06 19:47:10 +11001724config PADATA
1725 depends on SMP
1726 bool
1727
Andi Kleen754b7b62012-10-04 17:11:27 -07001728# Can be selected by architectures with broken toolchains
1729# that get confused by correct const<->read_only section
1730# mappings
1731config BROKEN_RODATA
1732 bool
1733
David Howells4520c6a2012-09-21 23:31:13 +01001734config ASN1
1735 tristate
1736 help
1737 Build a simple ASN.1 grammar compiler that produces a bytecode output
1738 that can be interpreted by the ASN.1 stream decoder and used to
1739 inform it as to what tags are to be expected in a stream and what
1740 functions to call on what tags.
1741
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001742source "kernel/Kconfig.locks"