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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56 drivers that have been replaced by something else, and/or are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 Weisbeckerabf917c2012-07-25 07:56:04 +0200329config VIRT_CPU_ACCOUNTING
330 bool
331
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200332choice
333 prompt "Cputime accounting"
334 default TICK_CPU_ACCOUNTING if !PPC64
335 default VIRT_CPU_ACCOUNTING if PPC64
336
337# Kind of a stub config for the pure tick based cputime accounting
338config TICK_CPU_ACCOUNTING
339 bool "Simple tick based cputime accounting"
340 depends on !S390
341 help
342 This is the basic tick based cputime accounting that maintains
343 statistics about user, system and idle time spent on per jiffies
344 granularity.
345
346 If unsure, say Y.
347
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200348config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200349 bool "Deterministic task and CPU time accounting"
350 depends on HAVE_VIRT_CPU_ACCOUNTING
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200351 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200352 help
353 Select this option to enable more accurate task and CPU time
354 accounting. This is done by reading a CPU counter on each
355 kernel entry and exit and on transitions within the kernel
356 between system, softirq and hardirq state, so there is a
357 small performance impact. In the case of s390 or IBM POWER > 5,
358 this also enables accounting of stolen time on logically-partitioned
359 systems.
360
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200361config VIRT_CPU_ACCOUNTING_GEN
362 bool "Full dynticks CPU time accounting"
363 depends on HAVE_CONTEXT_TRACKING && 64BIT
364 select VIRT_CPU_ACCOUNTING
365 select CONTEXT_TRACKING
366 help
367 Select this option to enable task and CPU time accounting on full
368 dynticks systems. This accounting is implemented by watching every
369 kernel-user boundaries using the context tracking subsystem.
370 The accounting is thus performed at the expense of some significant
371 overhead.
372
373 For now this is only useful if you are working on the full
374 dynticks subsystem development.
375
376 If unsure, say N.
377
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200378config IRQ_TIME_ACCOUNTING
379 bool "Fine granularity task level IRQ time accounting"
380 depends on HAVE_IRQ_TIME_ACCOUNTING
381 help
382 Select this option to enable fine granularity task irq time
383 accounting. This is done by reading a timestamp on each
384 transitions between softirq and hardirq state, so there can be a
385 small performance impact.
386
387 If in doubt, say N here.
388
389endchoice
390
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200391config BSD_PROCESS_ACCT
392 bool "BSD Process Accounting"
393 help
394 If you say Y here, a user level program will be able to instruct the
395 kernel (via a special system call) to write process accounting
396 information to a file: whenever a process exits, information about
397 that process will be appended to the file by the kernel. The
398 information includes things such as creation time, owning user,
399 command name, memory usage, controlling terminal etc. (the complete
400 list is in the struct acct in <file:include/linux/acct.h>). It is
401 up to the user level program to do useful things with this
402 information. This is generally a good idea, so say Y.
403
404config BSD_PROCESS_ACCT_V3
405 bool "BSD Process Accounting version 3 file format"
406 depends on BSD_PROCESS_ACCT
407 default n
408 help
409 If you say Y here, the process accounting information is written
410 in a new file format that also logs the process IDs of each
411 process and it's parent. Note that this file format is incompatible
412 with previous v0/v1/v2 file formats, so you will need updated tools
413 for processing it. A preliminary version of these tools is available
414 at <http://www.gnu.org/software/acct/>.
415
416config TASKSTATS
417 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
418 depends on NET
419 default n
420 help
421 Export selected statistics for tasks/processes through the
422 generic netlink interface. Unlike BSD process accounting, the
423 statistics are available during the lifetime of tasks/processes as
424 responses to commands. Like BSD accounting, they are sent to user
425 space on task exit.
426
427 Say N if unsure.
428
429config TASK_DELAY_ACCT
430 bool "Enable per-task delay accounting (EXPERIMENTAL)"
431 depends on TASKSTATS
432 help
433 Collect information on time spent by a task waiting for system
434 resources like cpu, synchronous block I/O completion and swapping
435 in pages. Such statistics can help in setting a task's priorities
436 relative to other tasks for cpu, io, rss limits etc.
437
438 Say N if unsure.
439
440config TASK_XACCT
441 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
442 depends on TASKSTATS
443 help
444 Collect extended task accounting data and send the data
445 to userland for processing over the taskstats interface.
446
447 Say N if unsure.
448
449config TASK_IO_ACCOUNTING
450 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
451 depends on TASK_XACCT
452 help
453 Collect information on the number of bytes of storage I/O which this
454 task has caused.
455
456 Say N if unsure.
457
458endmenu # "CPU/Task time and stats accounting"
459
Mike Travisc903ff82009-01-15 12:28:29 -0800460menu "RCU Subsystem"
461
462choice
463 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700464 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800465
Mike Travisc903ff82009-01-15 12:28:29 -0800466config TREE_RCU
467 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700468 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800469 help
470 This option selects the RCU implementation that is
471 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700472 thousands of CPUs. It also scales down nicely to
473 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800474
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700475config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700476 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700477 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700478 help
479 This option selects the RCU implementation that is
480 designed for very large SMP systems with hundreds or
481 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700482 is also required. It also scales down nicely to
483 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700484
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700485config TINY_RCU
486 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700487 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700488 help
489 This option selects the RCU implementation that is
490 designed for UP systems from which real-time response
491 is not required. This option greatly reduces the
492 memory footprint of RCU.
493
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700494config TINY_PREEMPT_RCU
495 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700496 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700497 help
498 This option selects the RCU implementation that is designed
499 for real-time UP systems. This option greatly reduces the
500 memory footprint of RCU.
501
Mike Travisc903ff82009-01-15 12:28:29 -0800502endchoice
503
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700504config PREEMPT_RCU
505 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
506 help
507 This option enables preemptible-RCU code that is common between
508 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
509
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100510config CONTEXT_TRACKING
511 bool
512
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200513config RCU_USER_QS
514 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100515 depends on HAVE_CONTEXT_TRACKING && SMP
516 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200517 help
518 This option sets hooks on kernel / userspace boundaries and
519 puts RCU in extended quiescent state when the CPU runs in
520 userspace. It means that when a CPU runs in userspace, it is
521 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700522 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200523
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200524 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100525 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700526 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200527
528 If unsure say N
529
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100530config CONTEXT_TRACKING_FORCE
531 bool "Force context tracking"
532 depends on CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200533 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100534 Probe on user/kernel boundaries by default in order to
535 test the features that rely on it such as userspace RCU extended
536 quiescent states.
537 This test is there for debugging until we have a real user like the
538 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200539
Mike Travisc903ff82009-01-15 12:28:29 -0800540config RCU_FANOUT
541 int "Tree-based hierarchical RCU fanout value"
542 range 2 64 if 64BIT
543 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700544 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800545 default 64 if 64BIT
546 default 32 if !64BIT
547 help
548 This option controls the fanout of hierarchical implementations
549 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700550 large numbers of CPUs. This value must be at least the fourth
551 root of NR_CPUS, which allows NR_CPUS to be insanely large.
552 The default value of RCU_FANOUT should be used for production
553 systems, but if you are stress-testing the RCU implementation
554 itself, small RCU_FANOUT values allow you to test large-system
555 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800556
557 Select a specific number if testing RCU itself.
558 Take the default if unsure.
559
Paul E. McKenney8932a632012-04-19 12:20:14 -0700560config RCU_FANOUT_LEAF
561 int "Tree-based hierarchical RCU leaf-level fanout value"
562 range 2 RCU_FANOUT if 64BIT
563 range 2 RCU_FANOUT if !64BIT
564 depends on TREE_RCU || TREE_PREEMPT_RCU
565 default 16
566 help
567 This option controls the leaf-level fanout of hierarchical
568 implementations of RCU, and allows trading off cache misses
569 against lock contention. Systems that synchronize their
570 scheduling-clock interrupts for energy-efficiency reasons will
571 want the default because the smaller leaf-level fanout keeps
572 lock contention levels acceptably low. Very large systems
573 (hundreds or thousands of CPUs) will instead want to set this
574 value to the maximum value possible in order to reduce the
575 number of cache misses incurred during RCU's grace-period
576 initialization. These systems tend to run CPU-bound, and thus
577 are not helped by synchronized interrupts, and thus tend to
578 skew them, which reduces lock contention enough that large
579 leaf-level fanouts work well.
580
581 Select a specific number if testing RCU itself.
582
583 Select the maximum permissible value for large systems.
584
585 Take the default if unsure.
586
Mike Travisc903ff82009-01-15 12:28:29 -0800587config RCU_FANOUT_EXACT
588 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700589 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800590 default n
591 help
592 This option forces use of the exact RCU_FANOUT value specified,
593 regardless of imbalances in the hierarchy. This is useful for
594 testing RCU itself, and might one day be useful on systems with
595 strong NUMA behavior.
596
597 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
598
599 Say N if unsure.
600
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800601config RCU_FAST_NO_HZ
602 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700603 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800604 default n
605 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700606 This option causes RCU to attempt to accelerate grace periods in
607 order to allow CPUs to enter dynticks-idle state more quickly.
608 On the other hand, this option increases the overhead of the
609 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800610
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700611 Say Y if energy efficiency is critically important, and you don't
612 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800613
614 Say N if you are unsure.
615
Mike Travisc903ff82009-01-15 12:28:29 -0800616config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700617 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800618 select DEBUG_FS
619 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700620 This option provides tracing for the TREE_RCU and
621 TREE_PREEMPT_RCU implementations, permitting Makefile to
622 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800623
Paul E. McKenney24278d12010-09-27 17:25:23 -0700624config RCU_BOOST
625 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800626 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700627 default n
628 help
629 This option boosts the priority of preempted RCU readers that
630 block the current preemptible RCU grace period for too long.
631 This option also prevents heavy loads from blocking RCU
632 callback invocation for all flavors of RCU.
633
634 Say Y here if you are working with real-time apps or heavy loads
635 Say N here if you are unsure.
636
637config RCU_BOOST_PRIO
638 int "Real-time priority to boost RCU readers to"
639 range 1 99
640 depends on RCU_BOOST
641 default 1
642 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700643 This option specifies the real-time priority to which long-term
644 preempted RCU readers are to be boosted. If you are working
645 with a real-time application that has one or more CPU-bound
646 threads running at a real-time priority level, you should set
647 RCU_BOOST_PRIO to a priority higher then the highest-priority
648 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
649 of 1 is appropriate in the common case, which is real-time
650 applications that do not have any CPU-bound threads.
651
652 Some real-time applications might not have a single real-time
653 thread that saturates a given CPU, but instead might have
654 multiple real-time threads that, taken together, fully utilize
655 that CPU. In this case, you should set RCU_BOOST_PRIO to
656 a priority higher than the lowest-priority thread that is
657 conspiring to prevent the CPU from running any non-real-time
658 tasks. For example, if one thread at priority 10 and another
659 thread at priority 5 are between themselves fully consuming
660 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
661 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700662
663 Specify the real-time priority, or take the default if unsure.
664
665config RCU_BOOST_DELAY
666 int "Milliseconds to delay boosting after RCU grace-period start"
667 range 0 3000
668 depends on RCU_BOOST
669 default 500
670 help
671 This option specifies the time to wait after the beginning of
672 a given grace period before priority-boosting preempted RCU
673 readers blocking that grace period. Note that any RCU reader
674 blocking an expedited RCU grace period is boosted immediately.
675
676 Accept the default if unsure.
677
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700678config RCU_NOCB_CPU
679 bool "Offload RCU callback processing from boot-selected CPUs"
680 depends on TREE_RCU || TREE_PREEMPT_RCU
681 default n
682 help
683 Use this option to reduce OS jitter for aggressive HPC or
684 real-time workloads. It can also be used to offload RCU
685 callback invocation to energy-efficient CPUs in battery-powered
686 asymmetric multiprocessors.
687
688 This option offloads callback invocation from the set of
689 CPUs specified at boot time by the rcu_nocbs parameter.
690 For each such CPU, a kthread ("rcuoN") will be created to
691 invoke callbacks, where the "N" is the CPU being offloaded.
692 Nothing prevents this kthread from running on the specified
693 CPUs, but (1) the kthreads may be preempted between each
694 callback, and (2) affinity or cgroups can be used to force
695 the kthreads to run on whatever set of CPUs is desired.
696
697 Say Y here if you want reduced OS jitter on selected CPUs.
698 Say N here if you are unsure.
699
Mike Travisc903ff82009-01-15 12:28:29 -0800700endmenu # "RCU Subsystem"
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700703 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 ---help---
705 This option enables the complete Linux kernel ".config" file
706 contents to be saved in the kernel. It provides documentation
707 of which kernel options are used in a running kernel or in an
708 on-disk kernel. This information can be extracted from the kernel
709 image file with the script scripts/extract-ikconfig and used as
710 input to rebuild the current kernel or to build another kernel.
711 It can also be extracted from a running kernel by reading
712 /proc/config.gz if enabled (below).
713
714config IKCONFIG_PROC
715 bool "Enable access to .config through /proc/config.gz"
716 depends on IKCONFIG && PROC_FS
717 ---help---
718 This option enables access to the kernel configuration file
719 through /proc/config.gz.
720
Alistair John Strachan794543a2007-05-08 00:31:15 -0700721config LOG_BUF_SHIFT
722 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
723 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700724 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700725 help
726 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700727 Examples:
728 17 => 128 KB
729 16 => 64 KB
730 15 => 32 KB
731 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700732 13 => 8 KB
733 12 => 4 KB
734
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800735#
736# Architectures with an unreliable sched_clock() should select this:
737#
738config HAVE_UNSTABLE_SCHED_CLOCK
739 bool
740
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200741#
742# For architectures that want to enable the support for NUMA-affine scheduler
743# balancing logic:
744#
745config ARCH_SUPPORTS_NUMA_BALANCING
746 bool
747
748# For architectures that (ab)use NUMA to represent different memory regions
749# all cpu-local but of different latencies, such as SuperH.
750#
751config ARCH_WANT_NUMA_VARIABLE_LOCALITY
752 bool
753
754#
755# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
756config ARCH_WANTS_PROT_NUMA_PROT_NONE
757 bool
758
759config ARCH_USES_NUMA_PROT_NONE
760 bool
761 default y
762 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
763 depends on NUMA_BALANCING
764
Mel Gorman1a687c22012-11-22 11:16:36 +0000765config NUMA_BALANCING_DEFAULT_ENABLED
766 bool "Automatically enable NUMA aware memory/task placement"
767 default y
768 depends on NUMA_BALANCING
769 help
770 If set, autonumic NUMA balancing will be enabled if running on a NUMA
771 machine.
772
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200773config NUMA_BALANCING
774 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200775 depends on ARCH_SUPPORTS_NUMA_BALANCING
776 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
777 depends on SMP && NUMA && MIGRATION
778 help
779 This option adds support for automatic NUMA aware memory/task placement.
780 The mechanism is quite primitive and is based on migrating memory when
781 it is references to the node the task is running on.
782
783 This system will be inactive on UMA systems.
784
Li Zefan23964d22009-01-15 13:50:58 -0800785menuconfig CGROUPS
786 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800787 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700788 help
Li Zefan23964d22009-01-15 13:50:58 -0800789 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800790 use with process control subsystems such as Cpusets, CFS, memory
791 controls or device isolation.
792 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800793 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800794 - Documentation/cgroups/ (features for grouping, isolation
795 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700796
797 Say N if unsure.
798
Li Zefan23964d22009-01-15 13:50:58 -0800799if CGROUPS
800
Paul Menage006cb992007-10-18 23:39:43 -0700801config CGROUP_DEBUG
802 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700803 default n
Paul Menage006cb992007-10-18 23:39:43 -0700804 help
805 This option enables a simple cgroup subsystem that
806 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800807 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700808
Li Zefan23964d22009-01-15 13:50:58 -0800809 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700810
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700811config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800812 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800813 help
814 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700815 cgroup.
816
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700817config CGROUP_DEVICE
818 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700819 help
820 Provides a cgroup implementing whitelists for devices which
821 a process in the cgroup can mknod or open.
822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823config CPUSETS
824 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700826 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 allow dynamically partitioning a system into sets of CPUs and
828 Memory Nodes and assigning tasks to run only within those sets.
829 This is primarily useful on large SMP or NUMA systems.
830
831 Say N if unsure.
832
Li Zefan23964d22009-01-15 13:50:58 -0800833config PROC_PID_CPUSET
834 bool "Include legacy /proc/<pid>/cpuset file"
835 depends on CPUSETS
836 default y
837
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100838config CGROUP_CPUACCT
839 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100840 help
841 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800842 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100843
Pavel Emelianove552b662008-02-07 00:13:49 -0800844config RESOURCE_COUNTERS
845 bool "Resource counters"
846 help
847 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800848 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800849
Andrew Mortonc255a452012-07-31 16:43:02 -0700850config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800851 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700852 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700853 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800854 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700855 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100856 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800857
858 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700859 associated with each page of memory in the system. By this,
860 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
861 usage tracking struct at boot. Total amount of this is printed out
862 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800863
864 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700865 sure you need the memory resource controller. Even when you enable
866 this, you can set "cgroup_disable=memory" at your boot option to
867 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800868 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800869
Balbir Singhcf475ad2008-04-29 01:00:16 -0700870 This config option also selects MM_OWNER config option, which
871 could in turn add some fork/exit overhead.
872
Andrew Mortonc255a452012-07-31 16:43:02 -0700873config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700874 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700875 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800876 help
877 Add swap management feature to memory resource controller. When you
878 enable this, you can limit mem+swap usage per cgroup. In other words,
879 when you disable this, memory resource controller has no cares to
880 usage of swap...a process can exhaust all of the swap. This extension
881 is useful when you want to avoid exhaustion swap but this itself
882 adds more overheads and consumes memory for remembering information.
883 Especially if you use 32bit system or small memory system, please
884 be careful about enabling this. When memory resource controller
885 is disabled by boot option, this will be automatically disabled and
886 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700887 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700888 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
889 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700890config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800891 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700892 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800893 default y
894 help
895 Memory Resource Controller Swap Extension comes with its price in
896 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700897 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800898 and let the user enable it by swapaccount boot command line
899 parameter should have this option unselected.
900 For those who want to have the feature enabled by default should
901 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700902 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700903config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000904 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700905 depends on MEMCG && EXPERIMENTAL
Glauber Costa510fc4e2012-12-18 14:21:47 -0800906 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000907 help
908 The Kernel Memory extension for Memory Resource Controller can limit
909 the amount of memory used by kernel objects in the system. Those are
910 fundamentally different from the entities handled by the standard
911 Memory Controller, which are page-based, and can be swapped. Users of
912 the kmem extension can use it to guarantee that no group of processes
913 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800914
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700915config CGROUP_HUGETLB
916 bool "HugeTLB Resource Controller for Control Groups"
917 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
918 default n
919 help
920 Provides a cgroup Resource Controller for HugeTLB pages.
921 When you enable this, you can put a per cgroup limit on HugeTLB usage.
922 The limit is enforced during page fault. Since HugeTLB doesn't
923 support page reclaim, enforcing the limit at page fault time implies
924 that, the application will get SIGBUS signal if it tries to access
925 HugeTLB pages beyond its limit. This requires the application to know
926 beforehand how much HugeTLB pages it would require for its use. The
927 control group is tracked in the third page lru pointer. This means
928 that we cannot use the controller with huge page less than 3 pages.
929
Stephane Eraniane5d13672011-02-14 11:20:01 +0200930config CGROUP_PERF
931 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
932 depends on PERF_EVENTS && CGROUPS
933 help
934 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800935 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200936 designated cpu.
937
938 Say N if unsure.
939
Dhaval Giani7c941432010-01-20 13:26:18 +0100940menuconfig CGROUP_SCHED
941 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100942 default n
943 help
944 This feature lets CPU scheduler recognize task groups and control CPU
945 bandwidth allocation to such task groups. It uses cgroups to group
946 tasks.
947
948if CGROUP_SCHED
949config FAIR_GROUP_SCHED
950 bool "Group scheduling for SCHED_OTHER"
951 depends on CGROUP_SCHED
952 default CGROUP_SCHED
953
Paul Turnerab84d312011-07-21 09:43:28 -0700954config CFS_BANDWIDTH
955 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
956 depends on EXPERIMENTAL
957 depends on FAIR_GROUP_SCHED
958 default n
959 help
960 This option allows users to define CPU bandwidth rates (limits) for
961 tasks running within the fair group scheduler. Groups with no limit
962 set are considered to be unconstrained and will run with no
963 restriction.
964 See tip/Documentation/scheduler/sched-bwc.txt for more information.
965
Dhaval Giani7c941432010-01-20 13:26:18 +0100966config RT_GROUP_SCHED
967 bool "Group scheduling for SCHED_RR/FIFO"
968 depends on EXPERIMENTAL
969 depends on CGROUP_SCHED
970 default n
971 help
972 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800973 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100974 schedule realtime tasks for non-root users until you allocate
975 realtime bandwidth for them.
976 See Documentation/scheduler/sched-rt-group.txt for more information.
977
978endif #CGROUP_SCHED
979
Vivek Goyalafc24d42010-04-26 19:27:56 +0200980config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800981 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700982 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200983 default n
984 ---help---
985 Generic block IO controller cgroup interface. This is the common
986 cgroup interface which should be used by various IO controlling
987 policies.
988
989 Currently, CFQ IO scheduler uses it to recognize task groups and
990 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400991 to such task groups. It is also used by bio throttling logic in
992 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200993
994 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400995 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000996 enabling proportional weight division of disk bandwidth in CFQ, set
997 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000998 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200999
1000 See Documentation/cgroups/blkio-controller.txt for more information.
1001
1002config DEBUG_BLK_CGROUP
1003 bool "Enable Block IO controller debugging"
1004 depends on BLK_CGROUP
1005 default n
1006 ---help---
1007 Enable some debugging help. Currently it exports additional stat
1008 files in a cgroup which can be useful for debugging.
1009
Li Zefan23964d22009-01-15 13:50:58 -08001010endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001011
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001012config CHECKPOINT_RESTORE
1013 bool "Checkpoint/restore support" if EXPERT
1014 default n
1015 help
1016 Enables additional kernel features in a sake of checkpoint/restore.
1017 In particular it adds auxiliary prctl codes to setup process text,
1018 data and heap segment sizes, and a few additional /proc filesystem
1019 entries.
1020
1021 If unsure, say N here.
1022
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001023menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001024 bool "Namespaces support" if EXPERT
1025 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001026 help
1027 Provides the way to make tasks work with different objects using
1028 the same id. For example same IPC id may refer to different objects
1029 or same user id or pid may refer to different tasks when used in
1030 different namespaces.
1031
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001032if NAMESPACES
1033
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001034config UTS_NS
1035 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001036 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001037 help
1038 In this namespace tasks see different info provided with the
1039 uname() system call
1040
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001041config IPC_NS
1042 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001043 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001044 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001045 help
1046 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001047 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001048
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001049config USER_NS
1050 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001051 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001052 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001053 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001054
Eric W. Biederman5673a942011-11-17 10:23:55 -08001055 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001056 help
1057 This allows containers, i.e. vservers, to use user namespaces
1058 to provide different user info for different servers.
1059 If unsure, say N.
1060
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001061config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001062 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001063 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001064 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001065 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001066 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001067 pid namespaces. This is a building block of containers.
1068
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001069config NET_NS
1070 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001071 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001072 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001073 help
1074 Allow user space to create what appear to be multiple instances
1075 of the network stack.
1076
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001077endif # NAMESPACES
1078
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001079config UIDGID_CONVERTED
1080 # True if all of the selected software conmponents are known
1081 # to have uid_t and gid_t converted to kuid_t and kgid_t
1082 # where appropriate and are otherwise safe to use with
1083 # the user namespace.
1084 bool
1085 default y
1086
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001087 # Networking
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001088 depends on NET_9P = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001089
1090 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001091 depends on 9P_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001092 depends on AFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001093 depends on CEPH_FS = n
1094 depends on CIFS = n
1095 depends on CODA_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001096 depends on GFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001097 depends on NCP_FS = n
1098 depends on NFSD = n
1099 depends on NFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001100 depends on OCFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001101 depends on XFS_FS = n
1102
Eric W. Biederman5673a942011-11-17 10:23:55 -08001103config UIDGID_STRICT_TYPE_CHECKS
1104 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001105 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001106 default n
1107 help
1108 While the nececessary conversions are being added to all subsystems this option allows
1109 the code to continue to build for unconverted subsystems.
1110
1111 Say Y here if you want the strict type checking enabled
1112
Mike Galbraith5091faa2010-11-30 14:18:03 +01001113config SCHED_AUTOGROUP
1114 bool "Automatic process group scheduling"
1115 select EVENTFD
1116 select CGROUPS
1117 select CGROUP_SCHED
1118 select FAIR_GROUP_SCHED
1119 help
1120 This option optimizes the scheduler for common desktop workloads by
1121 automatically creating and populating task groups. This separation
1122 of workloads isolates aggressive CPU burners (like build jobs) from
1123 desktop applications. Task group autogeneration is currently based
1124 upon task session.
1125
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001126config MM_OWNER
1127 bool
1128
1129config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001130 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001131 depends on SYSFS
1132 default n
1133 help
1134 This option adds code that switches the layout of the "block" class
1135 devices, to not show up in /sys/class/block/, but only in
1136 /sys/block/.
1137
1138 This switch is only active when the sysfs.deprecated=1 boot option is
1139 passed or the SYSFS_DEPRECATED_V2 option is set.
1140
1141 This option allows new kernels to run on old distributions and tools,
1142 which might get confused by /sys/class/block/. Since 2007/2008 all
1143 major distributions and tools handle this just fine.
1144
1145 Recent distributions and userspace tools after 2009/2010 depend on
1146 the existence of /sys/class/block/, and will not work with this
1147 option enabled.
1148
1149 Only if you are using a new kernel on an old distribution, you might
1150 need to say Y here.
1151
1152config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001153 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001154 default n
1155 depends on SYSFS
1156 depends on SYSFS_DEPRECATED
1157 help
1158 Enable deprecated sysfs by default.
1159
1160 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1161 option.
1162
1163 Only if you are using a new kernel on an old distribution, you might
1164 need to say Y here. Even then, odds are you would not need it
1165 enabled, you can always pass the boot option if absolutely necessary.
1166
1167config RELAY
1168 bool "Kernel->user space relay support (formerly relayfs)"
1169 help
1170 This option enables support for relay interface support in
1171 certain file systems (such as debugfs).
1172 It is designed to provide an efficient mechanism for tools and
1173 facilities to relay large amounts of data from kernel space to
1174 user space.
1175
1176 If unsure, say N.
1177
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001178config BLK_DEV_INITRD
1179 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1180 depends on BROKEN || !FRV
1181 help
1182 The initial RAM filesystem is a ramfs which is loaded by the
1183 boot loader (loadlin or lilo) and that is mounted as root
1184 before the normal boot procedure. It is typically used to
1185 load modules needed to mount the "real" root file system,
1186 etc. See <file:Documentation/initrd.txt> for details.
1187
1188 If RAM disk support (BLK_DEV_RAM) is also included, this
1189 also enables initial RAM disk (initrd) support and adds
1190 15 Kbytes (more on some other architectures) to the kernel size.
1191
1192 If unsure say Y.
1193
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001194if BLK_DEV_INITRD
1195
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001196source "usr/Kconfig"
1197
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001198endif
1199
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001200config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001201 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001202 help
1203 Enabling this option will pass "-Os" instead of "-O2" to gcc
1204 resulting in a smaller kernel.
1205
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001206 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001207
Randy Dunlap08470622006-09-30 23:28:13 -07001208config SYSCTL
1209 bool
1210
Randy Dunlapb943c462009-03-10 12:55:46 -07001211config ANON_INODES
1212 bool
1213
David Rientjes6a108a12011-01-20 14:44:16 -08001214menuconfig EXPERT
1215 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001216 # Unhide debug options, to make the on-by-default options visible
1217 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 help
1219 This option allows certain base kernel options and settings
1220 to be disabled or tweaked. This is for specialized
1221 environments which can tolerate a "non-standard" kernel.
1222 Only use this if you really know what you are doing.
1223
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001224config HAVE_UID16
1225 bool
1226
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001227config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001228 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001229 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001230 default y
1231 help
1232 This enables the legacy 16-bit UID syscall wrappers.
1233
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001234config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001235 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001236 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001237 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001238 select SYSCTL
1239 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001240 sys_sysctl uses binary paths that have been found challenging
1241 to properly maintain and use. The interface in /proc/sys
1242 using paths with ascii names is now the primary path to this
1243 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001244
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001245 Almost nothing using the binary sysctl interface so if you are
1246 trying to save some space it is probably safe to disable this,
1247 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001248
WANG Congc736de62011-11-02 13:39:25 -07001249 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001250
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001251config SYSCTL_EXCEPTION_TRACE
1252 bool
1253 help
1254 Enable support for /proc/sys/debug/exception-trace.
1255
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001257 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 default y
1259 help
1260 Say Y here to let the kernel print out symbolic crash information and
1261 symbolic stack backtraces. This increases the size of the kernel
1262 somewhat, as all symbols have to be loaded into the kernel image.
1263
1264config KALLSYMS_ALL
1265 bool "Include all symbols in kallsyms"
1266 depends on DEBUG_KERNEL && KALLSYMS
1267 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001268 Normally kallsyms only contains the symbols of functions for nicer
1269 OOPS messages and backtraces (i.e., symbols from the text and inittext
1270 sections). This is sufficient for most cases. And only in very rare
1271 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1272 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001274 This option makes sure that all symbols are loaded into the kernel
1275 image (i.e., symbols from all sections) in cost of increased kernel
1276 size (depending on the kernel configuration, it may be 300KiB or
1277 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001279 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001280
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001281config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001282 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001283
Matt Mackalld59745c2005-05-01 08:59:02 -07001284config PRINTK
1285 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001286 bool "Enable support for printk" if EXPERT
Matt Mackalld59745c2005-05-01 08:59:02 -07001287 help
1288 This option enables normal printk support. Removing it
1289 eliminates most of the message strings from the kernel image
1290 and makes the kernel more or less silent. As this makes it
1291 very difficult to diagnose system problems, saying N here is
1292 strongly discouraged.
1293
Matt Mackallc8538a72005-05-01 08:59:01 -07001294config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001295 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001296 default y
1297 help
1298 Disabling this option eliminates support for BUG and WARN, reducing
1299 the size of your kernel image and potentially quietly ignoring
1300 numerous fatal conditions. You should only consider disabling this
1301 option for embedded systems with no facilities for reporting errors.
1302 Just say Y.
1303
Matt Mackall708e9a72006-01-08 01:05:25 -08001304config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001305 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001306 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001307 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001308 help
1309 Enable support for generating core dumps. Disabling saves about 4k.
1310
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001311
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001312config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001313 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001314 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001315 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001316 default y
1317 help
1318 This option allows to disable the internal PC-Speaker
1319 support, saving some memory.
1320
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001321config HAVE_PCSPKR_PLATFORM
1322 bool
1323
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324config BASE_FULL
1325 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001326 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 help
1328 Disabling this option reduces the size of miscellaneous core
1329 kernel data structures. This saves memory on small machines,
1330 but may reduce performance.
1331
1332config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001333 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001335 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 help
1337 Disabling this option will cause the kernel to be built without
1338 support for "fast userspace mutexes". The resulting kernel may not
1339 run glibc-based applications correctly.
1340
1341config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001342 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001344 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 help
1346 Disabling this option will cause the kernel to be built without
1347 support for epoll family of system calls.
1348
Davide Libenzifba2afa2007-05-10 22:23:13 -07001349config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001350 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001351 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001352 default y
1353 help
1354 Enable the signalfd() system call that allows to receive signals
1355 on a file descriptor.
1356
1357 If unsure, say Y.
1358
Davide Libenzib215e282007-05-10 22:23:16 -07001359config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001360 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001361 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001362 default y
1363 help
1364 Enable the timerfd() system call that allows to receive timer
1365 events on a file descriptor.
1366
1367 If unsure, say Y.
1368
Davide Libenzie1ad7462007-05-10 22:23:19 -07001369config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001370 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001371 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001372 default y
1373 help
1374 Enable the eventfd() system call that allows to receive both
1375 kernel notification (ie. KAIO) or userspace notifications.
1376
1377 If unsure, say Y.
1378
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001380 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381 default y
1382 depends on MMU
1383 help
1384 The shmem is an internal filesystem used to manage shared memory.
1385 It is backed by swap and manages resource limits. It is also exported
1386 to userspace as tmpfs if TMPFS is enabled. Disabling this
1387 option replaces shmem and tmpfs with the much simpler ramfs code,
1388 which may be appropriate on small systems without swap.
1389
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001390config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001391 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001392 default y
1393 help
1394 This option enables POSIX asynchronous I/O which may by used
1395 by some high performance threaded applications. Disabling
1396 this option saves about 7k.
1397
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001398config EMBEDDED
1399 bool "Embedded system"
1400 select EXPERT
1401 help
1402 This option should be enabled if compiling the kernel for
1403 an embedded system so certain expert options are available
1404 for configuration.
1405
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001406config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001407 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001408 help
1409 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001410
Peter Zijlstra906010b2009-09-21 16:08:49 +02001411config PERF_USE_VMALLOC
1412 bool
1413 help
1414 See tools/perf/design.txt for details
1415
Ingo Molnar57c0c152009-09-21 12:20:38 +02001416menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001417
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001418config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001419 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001420 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001421 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001422 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001423 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001424 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001425 Enable kernel support for various performance events provided
1426 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001427
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001428 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001429 use of generic tracepoints.
1430
1431 Most modern CPUs support performance events via performance
1432 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001433 types of hw events: such as instructions executed, cachemisses
1434 suffered, or branches mis-predicted - without slowing down the
1435 kernel or applications. These registers can also trigger interrupts
1436 when a threshold number of events have passed - and can thus be
1437 used to profile the code that runs on that CPU.
1438
Ingo Molnar57c0c152009-09-21 12:20:38 +02001439 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001440 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001441 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001442 provides per task and per CPU counters, and it provides event
1443 capabilities on top of those.
1444
1445 Say Y if unsure.
1446
Peter Zijlstra906010b2009-09-21 16:08:49 +02001447config DEBUG_PERF_USE_VMALLOC
1448 default n
1449 bool "Debug: use vmalloc to back perf mmap() buffers"
1450 depends on PERF_EVENTS && DEBUG_KERNEL
1451 select PERF_USE_VMALLOC
1452 help
1453 Use vmalloc memory to back perf mmap() buffers.
1454
1455 Mostly useful for debugging the vmalloc code on platforms
1456 that don't require it.
1457
1458 Say N if unsure.
1459
Thomas Gleixner0793a612008-12-04 20:12:29 +01001460endmenu
1461
Christoph Lameterf8891e52006-06-30 01:55:45 -07001462config VM_EVENT_COUNTERS
1463 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001464 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001465 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001466 VM event counters are needed for event counts to be shown.
1467 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001468 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001469 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001470
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001471config PCI_QUIRKS
1472 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001473 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001474 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001475 help
1476 This enables workarounds for various PCI chipset
1477 bugs/quirks. Disable this only if your target machine is
1478 unaffected by PCI quirks.
1479
Christoph Lameter41ecc552007-05-09 02:32:44 -07001480config SLUB_DEBUG
1481 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001482 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001483 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001484 help
1485 SLUB has extensive debug support features. Disabling these can
1486 result in significant savings in code size. This also disables
1487 SLUB sysfs support. /sys/slab will not exist and there will be
1488 no support for cache validation etc.
1489
Randy Dunlapb943c462009-03-10 12:55:46 -07001490config COMPAT_BRK
1491 bool "Disable heap randomization"
1492 default y
1493 help
1494 Randomizing heap placement makes heap exploits harder, but it
1495 also breaks ancient binaries (including anything libc5 based).
1496 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001497 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001498 /proc/sys/kernel/randomize_va_space to 2.
1499
1500 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1501
Christoph Lameter81819f02007-05-06 14:49:36 -07001502choice
1503 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001504 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001505 help
1506 This option allows to select a slab allocator.
1507
1508config SLAB
1509 bool "SLAB"
1510 help
1511 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001512 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001513 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001514
1515config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001516 bool "SLUB (Unqueued Allocator)"
1517 help
1518 SLUB is a slab allocator that minimizes cache line usage
1519 instead of managing queues of cached objects (SLAB approach).
1520 Per cpu caching is realized using slabs of objects instead
1521 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001522 and has enhanced diagnostics. SLUB is the default choice for
1523 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001524
1525config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001526 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001527 bool "SLOB (Simple Allocator)"
1528 help
Matt Mackall37291452008-02-04 22:29:38 -08001529 SLOB replaces the stock allocator with a drastically simpler
1530 allocator. SLOB is generally more space efficient but
1531 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001532
1533endchoice
1534
Jie Zhangea637632009-12-14 18:00:02 -08001535config MMAP_ALLOW_UNINITIALIZED
1536 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001537 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001538 default n
1539 help
1540 Normally, and according to the Linux spec, anonymous memory obtained
1541 from mmap() has it's contents cleared before it is passed to
1542 userspace. Enabling this config option allows you to request that
1543 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1544 providing a huge performance boost. If this option is not enabled,
1545 then the flag will be ignored.
1546
1547 This is taken advantage of by uClibc's malloc(), and also by
1548 ELF-FDPIC binfmt's brk and stack allocator.
1549
1550 Because of the obvious security issues, this option should only be
1551 enabled on embedded devices where you control what is run in
1552 userspace. Since that isn't generally a problem on no-MMU systems,
1553 it is normally safe to say Y here.
1554
1555 See Documentation/nommu-mmap.txt for more information.
1556
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001557config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001558 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001559 help
1560 Say Y here to enable the extended profiling support mechanisms used
1561 by profilers such as OProfile.
1562
Ingo Molnar5f87f112008-07-23 14:15:22 +02001563#
1564# Place an empty function call at each tracepoint site. Can be
1565# dynamically changed for a probe function.
1566#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001567config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001568 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001569
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001570source "arch/Kconfig"
1571
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572endmenu # General setup
1573
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001574config HAVE_GENERIC_DMA_COHERENT
1575 bool
1576 default n
1577
Linus Torvalds158a9622008-01-02 13:04:48 -08001578config SLABINFO
1579 bool
1580 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001581 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001582 default y
1583
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001584config RT_MUTEXES
1585 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001586
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587config BASE_SMALL
1588 int
1589 default 0 if BASE_FULL
1590 default 1 if !BASE_FULL
1591
Jan Engelhardt66da5732007-07-15 23:39:29 -07001592menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001593 bool "Enable loadable module support"
1594 help
1595 Kernel modules are small pieces of compiled code which can
1596 be inserted in the running kernel, rather than being
1597 permanently built into the kernel. You use the "modprobe"
1598 tool to add (and sometimes remove) them. If you say Y here,
1599 many parts of the kernel can be built as modules (by
1600 answering M instead of Y where indicated): this is most
1601 useful for infrequently used options which are not required
1602 for booting. For more information, see the man pages for
1603 modprobe, lsmod, modinfo, insmod and rmmod.
1604
1605 If you say Y here, you will need to run "make
1606 modules_install" to put the modules under /lib/modules/
1607 where modprobe can find them (you may need to be root to do
1608 this).
1609
1610 If unsure, say Y.
1611
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001612if MODULES
1613
Linus Torvalds826e4502008-05-04 17:04:16 -07001614config MODULE_FORCE_LOAD
1615 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001616 default n
1617 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001618 Allow loading of modules without version information (ie. modprobe
1619 --force). Forced module loading sets the 'F' (forced) taint flag and
1620 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001621
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622config MODULE_UNLOAD
1623 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 help
1625 Without this option you will not be able to unload any
1626 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001627 anyway), which makes your kernel smaller, faster
1628 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629
1630config MODULE_FORCE_UNLOAD
1631 bool "Forced module unloading"
1632 depends on MODULE_UNLOAD && EXPERIMENTAL
1633 help
1634 This option allows you to force a module to unload, even if the
1635 kernel believes it is unsafe: the kernel will remove the module
1636 without waiting for anyone to stop using it (using the -f option to
1637 rmmod). This is mainly for kernel developers and desperate users.
1638 If unsure, say N.
1639
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001641 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642 help
1643 Usually, you have to use modules compiled with your kernel.
1644 Saying Y here makes it sometimes possible to use modules
1645 compiled for different kernels, by adding enough information
1646 to the modules to (hopefully) spot any changes which would
1647 make them incompatible with the kernel you are running. If
1648 unsure, say N.
1649
1650config MODULE_SRCVERSION_ALL
1651 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 help
1653 Modules which contain a MODULE_VERSION get an extra "srcversion"
1654 field inserted into their modinfo section, which contains a
1655 sum of the source files which made it. This helps maintainers
1656 see exactly which source was used to build a module (since
1657 others sometimes change the module source without updating
1658 the version). With this option, such a "srcversion" field
1659 will be created for all modules. If unsure, say N.
1660
Rusty Russell106a4ee2012-09-26 10:09:40 +01001661config MODULE_SIG
1662 bool "Module signature verification"
1663 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001664 select KEYS
1665 select CRYPTO
1666 select ASYMMETRIC_KEY_TYPE
1667 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1668 select PUBLIC_KEY_ALGO_RSA
1669 select ASN1
1670 select OID_REGISTRY
1671 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001672 help
1673 Check modules for valid signatures upon load: the signature
1674 is simply appended to the module. For more information see
1675 Documentation/module-signing.txt.
1676
David Howellsea0b6dc2012-09-26 10:09:50 +01001677 !!!WARNING!!! If you enable this option, you MUST make sure that the
1678 module DOES NOT get stripped after being signed. This includes the
1679 debuginfo strip done by some packagers (such as rpmbuild) and
1680 inclusion into an initramfs that wants the module size reduced.
1681
Rusty Russell106a4ee2012-09-26 10:09:40 +01001682config MODULE_SIG_FORCE
1683 bool "Require modules to be validly signed"
1684 depends on MODULE_SIG
1685 help
1686 Reject unsigned modules or signed modules for which we don't have a
1687 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001688
1689choice
1690 prompt "Which hash algorithm should modules be signed with?"
1691 depends on MODULE_SIG
1692 help
1693 This determines which sort of hashing algorithm will be used during
1694 signature generation. This algorithm _must_ be built into the kernel
1695 directly so that signature verification can take place. It is not
1696 possible to load a signed module containing the algorithm to check
1697 the signature on that module.
1698
1699config MODULE_SIG_SHA1
1700 bool "Sign modules with SHA-1"
1701 select CRYPTO_SHA1
1702
1703config MODULE_SIG_SHA224
1704 bool "Sign modules with SHA-224"
1705 select CRYPTO_SHA256
1706
1707config MODULE_SIG_SHA256
1708 bool "Sign modules with SHA-256"
1709 select CRYPTO_SHA256
1710
1711config MODULE_SIG_SHA384
1712 bool "Sign modules with SHA-384"
1713 select CRYPTO_SHA512
1714
1715config MODULE_SIG_SHA512
1716 bool "Sign modules with SHA-512"
1717 select CRYPTO_SHA512
1718
1719endchoice
1720
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001721endif # MODULES
1722
Rusty Russell98a79d62008-12-13 21:19:41 +10301723config INIT_ALL_POSSIBLE
1724 bool
1725 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301726 Back when each arch used to define their own cpu_online_mask and
1727 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301728 with all 1s, and others with all 0s. When they were centralised,
1729 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001730 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301731
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732config STOP_MACHINE
1733 bool
1734 default y
1735 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1736 help
1737 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001738
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001739source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001740
1741config PREEMPT_NOTIFIERS
1742 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001743
Steffen Klassert16295be2010-01-06 19:47:10 +11001744config PADATA
1745 depends on SMP
1746 bool
1747
Andi Kleen754b7b62012-10-04 17:11:27 -07001748# Can be selected by architectures with broken toolchains
1749# that get confused by correct const<->read_only section
1750# mappings
1751config BROKEN_RODATA
1752 bool
1753
David Howells4520c6a2012-09-21 23:31:13 +01001754config ASN1
1755 tristate
1756 help
1757 Build a simple ASN.1 grammar compiler that produces a bytecode output
1758 that can be interpreted by the ASN.1 stream decoder and used to
1759 inform it as to what tags are to be expected in a stream and what
1760 functions to call on what tags.
1761
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001762source "kernel/Kconfig.locks"