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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 IRQ_WORK
24 bool
Peter Zijlstrae360adb2010-10-14 14:01:34 +080025
David Daney1dbdc6f2012-04-19 14:59:57 -070026config BUILDTIME_EXTABLE_SORT
27 bool
28
Al Boldiff0cfc62007-07-31 00:39:23 -070029menu "General setup"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31config EXPERIMENTAL
32 bool "Prompt for development and/or incomplete code/drivers"
33 ---help---
34 Some of the various things that Linux supports (such as network
35 drivers, file systems, network protocols, etc.) can be in a state
36 of development where the functionality, stability, or the level of
37 testing is not yet high enough for general use. This is usually
38 known as the "alpha-test" phase among developers. If a feature is
39 currently in alpha-test, then the developers usually discourage
40 uninformed widespread use of this feature by the general public to
41 avoid "Why doesn't this work?" type mail messages. However, active
42 testing and use of these systems is welcomed. Just be aware that it
43 may not meet the normal level of reliability or it may fail to work
44 in some special cases. Detailed bug reports from people familiar
45 with the kernel internals are usually welcomed by the developers
46 (before submitting bug reports, please read the documents
47 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
48 <file:Documentation/BUG-HUNTING>, and
49 <file:Documentation/oops-tracing.txt> in the kernel source).
50
51 This option will also make obsoleted drivers available. These are
52 drivers that have been replaced by something else, and/or are
53 scheduled to be removed in a future kernel release.
54
55 Unless you intend to help test and develop a feature or driver that
56 falls into this category, or you have a situation that requires
57 using these features, you should probably say N here, which will
58 cause the configurator to present you with fewer choices. If
59 you say Y here, you will be offered the choice of using features or
60 drivers that are currently considered to be in the alpha-test phase.
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062config BROKEN
63 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65config BROKEN_ON_SMP
66 bool
67 depends on BROKEN || !SMP
68 default y
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070config INIT_ENV_ARG_LIMIT
71 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070072 default 32 if !UML
73 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080075 Maximum of each of the number of arguments and environment
76 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Roland McGrath84336462009-12-21 16:24:06 -080079config CROSS_COMPILE
80 string "Cross-compiler tool prefix"
81 help
82 Same as running 'make CROSS_COMPILE=prefix-' but stored for
83 default make runs in this kernel build directory. You don't
84 need to set this unless you want the configured kernel build
85 directory to select the cross-compiler automatically.
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087config LOCALVERSION
88 string "Local version - append to kernel release"
89 help
90 Append an extra string to the end of your kernel version.
91 This will show up when you type uname, for example.
92 The string you set here will be appended after the contents of
93 any files with a filename matching localversion* in your
94 object and source tree, in that order. Your total string can
95 be a maximum of 64 characters.
96
Ryan Andersonaaebf432005-07-31 04:57:49 -040097config LOCALVERSION_AUTO
98 bool "Automatically append version information to the version string"
99 default y
100 help
101 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200102 release tree by looking for git tags that belong to the current
103 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400104
105 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200106 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -0400107 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200108 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -0400109
Robert P. J. Day6e5a5422007-05-01 23:08:11 +0200110 (The actual string used here is the first eight characters produced
111 by running the command:
112
113 $ git rev-parse --verify HEAD
114
115 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -0400116
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800117config HAVE_KERNEL_GZIP
118 bool
119
120config HAVE_KERNEL_BZIP2
121 bool
122
123config HAVE_KERNEL_LZMA
124 bool
125
Lasse Collin3ebe1242011-01-12 17:01:23 -0800126config HAVE_KERNEL_XZ
127 bool
128
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800129config HAVE_KERNEL_LZO
130 bool
131
Alain Knaff30d65db2009-01-04 22:46:17 +0100132choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800133 prompt "Kernel compression mode"
134 default KERNEL_GZIP
Lasse Collin3ebe1242011-01-12 17:01:23 -0800135 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 -0800136 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100137 The linux kernel is a kind of self-extracting executable.
138 Several compression algorithms are available, which differ
139 in efficiency, compression and decompression speed.
140 Compression speed is only relevant when building a kernel.
141 Decompression speed is relevant at each boot.
142
143 If you have any problems with bzip2 or lzma compressed
144 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
145 version of this functionality (bzip2 only), for 2.4, was
146 supplied by Christian Ludwig)
147
148 High compression options are mostly useful for users, who
149 are low on disk space (embedded systems), but for whom ram
150 size matters less.
151
152 If in doubt, select 'gzip'
153
154config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800155 bool "Gzip"
156 depends on HAVE_KERNEL_GZIP
157 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800158 The old and tried gzip compression. It provides a good balance
159 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100160
161config KERNEL_BZIP2
162 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800163 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100164 help
165 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700166 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800167 size is about 10% smaller with bzip2, in comparison to gzip.
168 Bzip2 uses a large amount of memory. For modern kernels you
169 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100170
171config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800172 bool "LZMA"
173 depends on HAVE_KERNEL_LZMA
174 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700175 This compression algorithm's ratio is best. Decompression speed
176 is between gzip and bzip2. Compression is slowest.
177 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100178
Lasse Collin3ebe1242011-01-12 17:01:23 -0800179config KERNEL_XZ
180 bool "XZ"
181 depends on HAVE_KERNEL_XZ
182 help
183 XZ uses the LZMA2 algorithm and instruction set specific
184 BCJ filters which can improve compression ratio of executable
185 code. The size of the kernel is about 30% smaller with XZ in
186 comparison to gzip. On architectures for which there is a BCJ
187 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
188 will create a few percent smaller kernel than plain LZMA.
189
190 The speed is about the same as with LZMA: The decompression
191 speed of XZ is better than that of bzip2 but worse than gzip
192 and LZO. Compression is slow.
193
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800194config KERNEL_LZO
195 bool "LZO"
196 depends on HAVE_KERNEL_LZO
197 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700198 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200199 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800200 (both compression and decompression) is the fastest.
201
Alain Knaff30d65db2009-01-04 22:46:17 +0100202endchoice
203
Josh Triplettbd5dc172011-06-15 15:08:28 -0700204config DEFAULT_HOSTNAME
205 string "Default hostname"
206 default "(none)"
207 help
208 This option determines the default system hostname before userspace
209 calls sethostname(2). The kernel traditionally uses "(none)" here,
210 but you may wish to use a different default here to make a minimal
211 system more usable with less configuration.
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213config SWAP
214 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200215 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 default y
217 help
218 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100219 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 used to provide more virtual memory than the actual RAM present
221 in your computer. If unsure say Y.
222
223config SYSVIPC
224 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 ---help---
226 Inter Process Communication is a suite of library functions and
227 system calls which let processes (running programs) synchronize and
228 exchange information. It is generally considered to be a good thing,
229 and some programs won't run unless you say Y here. In particular, if
230 you want to run the DOS emulator dosemu under Linux (read the
231 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
232 you'll need to say Y here.
233
234 You can find documentation about IPC with "info ipc" and also in
235 section 6.4 of the Linux Programmer's Guide, available from
236 <http://www.tldp.org/guides.html>.
237
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800238config SYSVIPC_SYSCTL
239 bool
240 depends on SYSVIPC
241 depends on SYSCTL
242 default y
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244config POSIX_MQUEUE
245 bool "POSIX Message Queues"
246 depends on NET && EXPERIMENTAL
247 ---help---
248 POSIX variant of message queues is a part of IPC. In POSIX message
249 queues every message has a priority which decides about succession
250 of receiving it by a process. If you want to compile and run
251 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200252 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
254 POSIX message queues are visible as a filesystem called 'mqueue'
255 and can be mounted somewhere if you want to do filesystem
256 operations on message queues.
257
258 If unsure, say Y.
259
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700260config POSIX_MQUEUE_SYSCTL
261 bool
262 depends on POSIX_MQUEUE
263 depends on SYSCTL
264 default y
265
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530266config FHANDLE
267 bool "open by fhandle syscalls"
268 select EXPORTFS
269 help
270 If you say Y here, a user level program will be able to map
271 file names to handle and then later use the handle for
272 different file system operations. This is useful in implementing
273 userspace file servers, which now track files using handles instead
274 of names. The handle would remain the same even if file names
275 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
276 syscalls.
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278config AUDIT
279 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100280 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 help
282 Enable auditing infrastructure that can be used with another
283 kernel subsystem, such as SELinux (which requires this for
284 logging of avc messages output). Does not do system-call
285 auditing without CONFIG_AUDITSYSCALL.
286
287config AUDITSYSCALL
288 bool "Enable system-call auditing support"
Will Deacon8f827a12012-07-06 15:48:16 +0100289 depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 default y if SECURITY_SELINUX
291 help
292 Enable low-overhead system-call auditing infrastructure that
293 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500294 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Eric Paris939a67f2009-12-17 20:12:06 -0500296config AUDIT_WATCH
297 def_bool y
298 depends on AUDITSYSCALL
299 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
Al Viro74c3cbe2007-07-22 08:04:18 -0400301config AUDIT_TREE
302 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400303 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500304 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400305
Eric Paris633b4542012-01-03 14:23:08 -0500306config AUDIT_LOGINUID_IMMUTABLE
307 bool "Make audit loginuid immutable"
308 depends on AUDIT
309 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800310 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500311 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
312 but should instead only allow setting its loginuid if it was never
313 previously set. On systems which use systemd or a similar central
314 process to restart login services this should be set to true. On older
315 systems in which an admin would typically have to directly stop and
316 start processes this should be set to false. Setting this to true allows
317 one to drop potentially dangerous capabilites from the login tasks,
318 but may not be backwards compatible with older init systems.
319
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000320source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200321source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000322
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200323menu "CPU/Task time and stats accounting"
324
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200325choice
326 prompt "Cputime accounting"
327 default TICK_CPU_ACCOUNTING if !PPC64
328 default VIRT_CPU_ACCOUNTING if PPC64
329
330# Kind of a stub config for the pure tick based cputime accounting
331config TICK_CPU_ACCOUNTING
332 bool "Simple tick based cputime accounting"
333 depends on !S390
334 help
335 This is the basic tick based cputime accounting that maintains
336 statistics about user, system and idle time spent on per jiffies
337 granularity.
338
339 If unsure, say Y.
340
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200341config VIRT_CPU_ACCOUNTING
342 bool "Deterministic task and CPU time accounting"
343 depends on HAVE_VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200344 help
345 Select this option to enable more accurate task and CPU time
346 accounting. This is done by reading a CPU counter on each
347 kernel entry and exit and on transitions within the kernel
348 between system, softirq and hardirq state, so there is a
349 small performance impact. In the case of s390 or IBM POWER > 5,
350 this also enables accounting of stolen time on logically-partitioned
351 systems.
352
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200353config IRQ_TIME_ACCOUNTING
354 bool "Fine granularity task level IRQ time accounting"
355 depends on HAVE_IRQ_TIME_ACCOUNTING
356 help
357 Select this option to enable fine granularity task irq time
358 accounting. This is done by reading a timestamp on each
359 transitions between softirq and hardirq state, so there can be a
360 small performance impact.
361
362 If in doubt, say N here.
363
364endchoice
365
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200366config BSD_PROCESS_ACCT
367 bool "BSD Process Accounting"
368 help
369 If you say Y here, a user level program will be able to instruct the
370 kernel (via a special system call) to write process accounting
371 information to a file: whenever a process exits, information about
372 that process will be appended to the file by the kernel. The
373 information includes things such as creation time, owning user,
374 command name, memory usage, controlling terminal etc. (the complete
375 list is in the struct acct in <file:include/linux/acct.h>). It is
376 up to the user level program to do useful things with this
377 information. This is generally a good idea, so say Y.
378
379config BSD_PROCESS_ACCT_V3
380 bool "BSD Process Accounting version 3 file format"
381 depends on BSD_PROCESS_ACCT
382 default n
383 help
384 If you say Y here, the process accounting information is written
385 in a new file format that also logs the process IDs of each
386 process and it's parent. Note that this file format is incompatible
387 with previous v0/v1/v2 file formats, so you will need updated tools
388 for processing it. A preliminary version of these tools is available
389 at <http://www.gnu.org/software/acct/>.
390
391config TASKSTATS
392 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
393 depends on NET
394 default n
395 help
396 Export selected statistics for tasks/processes through the
397 generic netlink interface. Unlike BSD process accounting, the
398 statistics are available during the lifetime of tasks/processes as
399 responses to commands. Like BSD accounting, they are sent to user
400 space on task exit.
401
402 Say N if unsure.
403
404config TASK_DELAY_ACCT
405 bool "Enable per-task delay accounting (EXPERIMENTAL)"
406 depends on TASKSTATS
407 help
408 Collect information on time spent by a task waiting for system
409 resources like cpu, synchronous block I/O completion and swapping
410 in pages. Such statistics can help in setting a task's priorities
411 relative to other tasks for cpu, io, rss limits etc.
412
413 Say N if unsure.
414
415config TASK_XACCT
416 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
417 depends on TASKSTATS
418 help
419 Collect extended task accounting data and send the data
420 to userland for processing over the taskstats interface.
421
422 Say N if unsure.
423
424config TASK_IO_ACCOUNTING
425 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
426 depends on TASK_XACCT
427 help
428 Collect information on the number of bytes of storage I/O which this
429 task has caused.
430
431 Say N if unsure.
432
433endmenu # "CPU/Task time and stats accounting"
434
Mike Travisc903ff82009-01-15 12:28:29 -0800435menu "RCU Subsystem"
436
437choice
438 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700439 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800440
Mike Travisc903ff82009-01-15 12:28:29 -0800441config TREE_RCU
442 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700443 depends on !PREEMPT && SMP
Mike Travisc903ff82009-01-15 12:28:29 -0800444 help
445 This option selects the RCU implementation that is
446 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700447 thousands of CPUs. It also scales down nicely to
448 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800449
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700450config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700451 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700452 depends on PREEMPT && SMP
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700453 help
454 This option selects the RCU implementation that is
455 designed for very large SMP systems with hundreds or
456 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700457 is also required. It also scales down nicely to
458 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700459
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700460config TINY_RCU
461 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700462 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700463 help
464 This option selects the RCU implementation that is
465 designed for UP systems from which real-time response
466 is not required. This option greatly reduces the
467 memory footprint of RCU.
468
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700469config TINY_PREEMPT_RCU
470 bool "Preemptible UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700471 depends on PREEMPT && !SMP
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700472 help
473 This option selects the RCU implementation that is designed
474 for real-time UP systems. This option greatly reduces the
475 memory footprint of RCU.
476
Mike Travisc903ff82009-01-15 12:28:29 -0800477endchoice
478
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700479config PREEMPT_RCU
480 def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
481 help
482 This option enables preemptible-RCU code that is common between
483 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
484
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100485config CONTEXT_TRACKING
486 bool
487
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200488config RCU_USER_QS
489 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100490 depends on HAVE_CONTEXT_TRACKING && SMP
491 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200492 help
493 This option sets hooks on kernel / userspace boundaries and
494 puts RCU in extended quiescent state when the CPU runs in
495 userspace. It means that when a CPU runs in userspace, it is
496 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700497 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200498
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200499 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100500 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700501 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200502
503 If unsure say N
504
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100505config CONTEXT_TRACKING_FORCE
506 bool "Force context tracking"
507 depends on CONTEXT_TRACKING
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200508 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100509 Probe on user/kernel boundaries by default in order to
510 test the features that rely on it such as userspace RCU extended
511 quiescent states.
512 This test is there for debugging until we have a real user like the
513 full dynticks mode.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200514
Mike Travisc903ff82009-01-15 12:28:29 -0800515config RCU_FANOUT
516 int "Tree-based hierarchical RCU fanout value"
517 range 2 64 if 64BIT
518 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700519 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800520 default 64 if 64BIT
521 default 32 if !64BIT
522 help
523 This option controls the fanout of hierarchical implementations
524 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700525 large numbers of CPUs. This value must be at least the fourth
526 root of NR_CPUS, which allows NR_CPUS to be insanely large.
527 The default value of RCU_FANOUT should be used for production
528 systems, but if you are stress-testing the RCU implementation
529 itself, small RCU_FANOUT values allow you to test large-system
530 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800531
532 Select a specific number if testing RCU itself.
533 Take the default if unsure.
534
Paul E. McKenney8932a632012-04-19 12:20:14 -0700535config RCU_FANOUT_LEAF
536 int "Tree-based hierarchical RCU leaf-level fanout value"
537 range 2 RCU_FANOUT if 64BIT
538 range 2 RCU_FANOUT if !64BIT
539 depends on TREE_RCU || TREE_PREEMPT_RCU
540 default 16
541 help
542 This option controls the leaf-level fanout of hierarchical
543 implementations of RCU, and allows trading off cache misses
544 against lock contention. Systems that synchronize their
545 scheduling-clock interrupts for energy-efficiency reasons will
546 want the default because the smaller leaf-level fanout keeps
547 lock contention levels acceptably low. Very large systems
548 (hundreds or thousands of CPUs) will instead want to set this
549 value to the maximum value possible in order to reduce the
550 number of cache misses incurred during RCU's grace-period
551 initialization. These systems tend to run CPU-bound, and thus
552 are not helped by synchronized interrupts, and thus tend to
553 skew them, which reduces lock contention enough that large
554 leaf-level fanouts work well.
555
556 Select a specific number if testing RCU itself.
557
558 Select the maximum permissible value for large systems.
559
560 Take the default if unsure.
561
Mike Travisc903ff82009-01-15 12:28:29 -0800562config RCU_FANOUT_EXACT
563 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700564 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800565 default n
566 help
567 This option forces use of the exact RCU_FANOUT value specified,
568 regardless of imbalances in the hierarchy. This is useful for
569 testing RCU itself, and might one day be useful on systems with
570 strong NUMA behavior.
571
572 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
573
574 Say N if unsure.
575
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800576config RCU_FAST_NO_HZ
577 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Paul E. McKenneyb807fbf2011-11-03 14:56:12 -0700578 depends on NO_HZ && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800579 default n
580 help
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700581 This option causes RCU to attempt to accelerate grace periods in
582 order to allow CPUs to enter dynticks-idle state more quickly.
583 On the other hand, this option increases the overhead of the
584 dynticks-idle checking, thus degrading scheduling latency.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800585
Paul E. McKenneyba49df42012-10-07 09:26:13 -0700586 Say Y if energy efficiency is critically important, and you don't
587 care about real-time response.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800588
589 Say N if you are unsure.
590
Mike Travisc903ff82009-01-15 12:28:29 -0800591config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700592 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800593 select DEBUG_FS
594 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700595 This option provides tracing for the TREE_RCU and
596 TREE_PREEMPT_RCU implementations, permitting Makefile to
597 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800598
Paul E. McKenney24278d12010-09-27 17:25:23 -0700599config RCU_BOOST
600 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800601 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700602 default n
603 help
604 This option boosts the priority of preempted RCU readers that
605 block the current preemptible RCU grace period for too long.
606 This option also prevents heavy loads from blocking RCU
607 callback invocation for all flavors of RCU.
608
609 Say Y here if you are working with real-time apps or heavy loads
610 Say N here if you are unsure.
611
612config RCU_BOOST_PRIO
613 int "Real-time priority to boost RCU readers to"
614 range 1 99
615 depends on RCU_BOOST
616 default 1
617 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700618 This option specifies the real-time priority to which long-term
619 preempted RCU readers are to be boosted. If you are working
620 with a real-time application that has one or more CPU-bound
621 threads running at a real-time priority level, you should set
622 RCU_BOOST_PRIO to a priority higher then the highest-priority
623 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
624 of 1 is appropriate in the common case, which is real-time
625 applications that do not have any CPU-bound threads.
626
627 Some real-time applications might not have a single real-time
628 thread that saturates a given CPU, but instead might have
629 multiple real-time threads that, taken together, fully utilize
630 that CPU. In this case, you should set RCU_BOOST_PRIO to
631 a priority higher than the lowest-priority thread that is
632 conspiring to prevent the CPU from running any non-real-time
633 tasks. For example, if one thread at priority 10 and another
634 thread at priority 5 are between themselves fully consuming
635 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
636 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700637
638 Specify the real-time priority, or take the default if unsure.
639
640config RCU_BOOST_DELAY
641 int "Milliseconds to delay boosting after RCU grace-period start"
642 range 0 3000
643 depends on RCU_BOOST
644 default 500
645 help
646 This option specifies the time to wait after the beginning of
647 a given grace period before priority-boosting preempted RCU
648 readers blocking that grace period. Note that any RCU reader
649 blocking an expedited RCU grace period is boosted immediately.
650
651 Accept the default if unsure.
652
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700653config RCU_NOCB_CPU
654 bool "Offload RCU callback processing from boot-selected CPUs"
655 depends on TREE_RCU || TREE_PREEMPT_RCU
656 default n
657 help
658 Use this option to reduce OS jitter for aggressive HPC or
659 real-time workloads. It can also be used to offload RCU
660 callback invocation to energy-efficient CPUs in battery-powered
661 asymmetric multiprocessors.
662
663 This option offloads callback invocation from the set of
664 CPUs specified at boot time by the rcu_nocbs parameter.
665 For each such CPU, a kthread ("rcuoN") will be created to
666 invoke callbacks, where the "N" is the CPU being offloaded.
667 Nothing prevents this kthread from running on the specified
668 CPUs, but (1) the kthreads may be preempted between each
669 callback, and (2) affinity or cgroups can be used to force
670 the kthreads to run on whatever set of CPUs is desired.
671
672 Say Y here if you want reduced OS jitter on selected CPUs.
673 Say N here if you are unsure.
674
Mike Travisc903ff82009-01-15 12:28:29 -0800675endmenu # "RCU Subsystem"
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700678 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 ---help---
680 This option enables the complete Linux kernel ".config" file
681 contents to be saved in the kernel. It provides documentation
682 of which kernel options are used in a running kernel or in an
683 on-disk kernel. This information can be extracted from the kernel
684 image file with the script scripts/extract-ikconfig and used as
685 input to rebuild the current kernel or to build another kernel.
686 It can also be extracted from a running kernel by reading
687 /proc/config.gz if enabled (below).
688
689config IKCONFIG_PROC
690 bool "Enable access to .config through /proc/config.gz"
691 depends on IKCONFIG && PROC_FS
692 ---help---
693 This option enables access to the kernel configuration file
694 through /proc/config.gz.
695
Alistair John Strachan794543a2007-05-08 00:31:15 -0700696config LOG_BUF_SHIFT
697 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
698 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700699 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700700 help
701 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700702 Examples:
703 17 => 128 KB
704 16 => 64 KB
705 15 => 32 KB
706 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700707 13 => 8 KB
708 12 => 4 KB
709
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800710#
711# Architectures with an unreliable sched_clock() should select this:
712#
713config HAVE_UNSTABLE_SCHED_CLOCK
714 bool
715
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200716#
717# For architectures that want to enable the support for NUMA-affine scheduler
718# balancing logic:
719#
720config ARCH_SUPPORTS_NUMA_BALANCING
721 bool
722
723# For architectures that (ab)use NUMA to represent different memory regions
724# all cpu-local but of different latencies, such as SuperH.
725#
726config ARCH_WANT_NUMA_VARIABLE_LOCALITY
727 bool
728
729#
730# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
731config ARCH_WANTS_PROT_NUMA_PROT_NONE
732 bool
733
734config ARCH_USES_NUMA_PROT_NONE
735 bool
736 default y
737 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
738 depends on NUMA_BALANCING
739
Mel Gorman1a687c22012-11-22 11:16:36 +0000740config NUMA_BALANCING_DEFAULT_ENABLED
741 bool "Automatically enable NUMA aware memory/task placement"
742 default y
743 depends on NUMA_BALANCING
744 help
745 If set, autonumic NUMA balancing will be enabled if running on a NUMA
746 machine.
747
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200748config NUMA_BALANCING
749 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200750 depends on ARCH_SUPPORTS_NUMA_BALANCING
751 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
752 depends on SMP && NUMA && MIGRATION
753 help
754 This option adds support for automatic NUMA aware memory/task placement.
755 The mechanism is quite primitive and is based on migrating memory when
756 it is references to the node the task is running on.
757
758 This system will be inactive on UMA systems.
759
Li Zefan23964d22009-01-15 13:50:58 -0800760menuconfig CGROUPS
761 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800762 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700763 help
Li Zefan23964d22009-01-15 13:50:58 -0800764 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800765 use with process control subsystems such as Cpusets, CFS, memory
766 controls or device isolation.
767 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800768 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800769 - Documentation/cgroups/ (features for grouping, isolation
770 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700771
772 Say N if unsure.
773
Li Zefan23964d22009-01-15 13:50:58 -0800774if CGROUPS
775
Paul Menage006cb992007-10-18 23:39:43 -0700776config CGROUP_DEBUG
777 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700778 default n
Paul Menage006cb992007-10-18 23:39:43 -0700779 help
780 This option enables a simple cgroup subsystem that
781 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800782 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700783
Li Zefan23964d22009-01-15 13:50:58 -0800784 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700785
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700786config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800787 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800788 help
789 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700790 cgroup.
791
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700792config CGROUP_DEVICE
793 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700794 help
795 Provides a cgroup implementing whitelists for devices which
796 a process in the cgroup can mknod or open.
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798config CPUSETS
799 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700801 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 allow dynamically partitioning a system into sets of CPUs and
803 Memory Nodes and assigning tasks to run only within those sets.
804 This is primarily useful on large SMP or NUMA systems.
805
806 Say N if unsure.
807
Li Zefan23964d22009-01-15 13:50:58 -0800808config PROC_PID_CPUSET
809 bool "Include legacy /proc/<pid>/cpuset file"
810 depends on CPUSETS
811 default y
812
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100813config CGROUP_CPUACCT
814 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100815 help
816 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800817 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100818
Pavel Emelianove552b662008-02-07 00:13:49 -0800819config RESOURCE_COUNTERS
820 bool "Resource counters"
821 help
822 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800823 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800824
Andrew Mortonc255a452012-07-31 16:43:02 -0700825config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800826 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700827 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700828 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800829 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700830 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100831 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800832
833 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700834 associated with each page of memory in the system. By this,
835 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
836 usage tracking struct at boot. Total amount of this is printed out
837 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800838
839 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700840 sure you need the memory resource controller. Even when you enable
841 this, you can set "cgroup_disable=memory" at your boot option to
842 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800843 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800844
Balbir Singhcf475ad2008-04-29 01:00:16 -0700845 This config option also selects MM_OWNER config option, which
846 could in turn add some fork/exit overhead.
847
Andrew Mortonc255a452012-07-31 16:43:02 -0700848config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700849 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700850 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800851 help
852 Add swap management feature to memory resource controller. When you
853 enable this, you can limit mem+swap usage per cgroup. In other words,
854 when you disable this, memory resource controller has no cares to
855 usage of swap...a process can exhaust all of the swap. This extension
856 is useful when you want to avoid exhaustion swap but this itself
857 adds more overheads and consumes memory for remembering information.
858 Especially if you use 32bit system or small memory system, please
859 be careful about enabling this. When memory resource controller
860 is disabled by boot option, this will be automatically disabled and
861 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700862 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700863 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
864 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700865config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800866 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700867 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800868 default y
869 help
870 Memory Resource Controller Swap Extension comes with its price in
871 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700872 which want to enable the feature but keep it disabled by default
Michal Hockoa42c3902010-11-24 12:57:08 -0800873 and let the user enable it by swapaccount boot command line
874 parameter should have this option unselected.
875 For those who want to have the feature enabled by default should
876 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700877 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700878config MEMCG_KMEM
Glauber Costae5671df2011-12-11 21:47:01 +0000879 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
Andrew Mortonc255a452012-07-31 16:43:02 -0700880 depends on MEMCG && EXPERIMENTAL
Glauber Costa510fc4e2012-12-18 14:21:47 -0800881 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000882 help
883 The Kernel Memory extension for Memory Resource Controller can limit
884 the amount of memory used by kernel objects in the system. Those are
885 fundamentally different from the entities handled by the standard
886 Memory Controller, which are page-based, and can be swapped. Users of
887 the kmem extension can use it to guarantee that no group of processes
888 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800889
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700890config CGROUP_HUGETLB
891 bool "HugeTLB Resource Controller for Control Groups"
892 depends on RESOURCE_COUNTERS && HUGETLB_PAGE && EXPERIMENTAL
893 default n
894 help
895 Provides a cgroup Resource Controller for HugeTLB pages.
896 When you enable this, you can put a per cgroup limit on HugeTLB usage.
897 The limit is enforced during page fault. Since HugeTLB doesn't
898 support page reclaim, enforcing the limit at page fault time implies
899 that, the application will get SIGBUS signal if it tries to access
900 HugeTLB pages beyond its limit. This requires the application to know
901 beforehand how much HugeTLB pages it would require for its use. The
902 control group is tracked in the third page lru pointer. This means
903 that we cannot use the controller with huge page less than 3 pages.
904
Stephane Eraniane5d13672011-02-14 11:20:01 +0200905config CGROUP_PERF
906 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
907 depends on PERF_EVENTS && CGROUPS
908 help
909 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +0800910 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +0200911 designated cpu.
912
913 Say N if unsure.
914
Dhaval Giani7c941432010-01-20 13:26:18 +0100915menuconfig CGROUP_SCHED
916 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +0100917 default n
918 help
919 This feature lets CPU scheduler recognize task groups and control CPU
920 bandwidth allocation to such task groups. It uses cgroups to group
921 tasks.
922
923if CGROUP_SCHED
924config FAIR_GROUP_SCHED
925 bool "Group scheduling for SCHED_OTHER"
926 depends on CGROUP_SCHED
927 default CGROUP_SCHED
928
Paul Turnerab84d312011-07-21 09:43:28 -0700929config CFS_BANDWIDTH
930 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
931 depends on EXPERIMENTAL
932 depends on FAIR_GROUP_SCHED
933 default n
934 help
935 This option allows users to define CPU bandwidth rates (limits) for
936 tasks running within the fair group scheduler. Groups with no limit
937 set are considered to be unconstrained and will run with no
938 restriction.
939 See tip/Documentation/scheduler/sched-bwc.txt for more information.
940
Dhaval Giani7c941432010-01-20 13:26:18 +0100941config RT_GROUP_SCHED
942 bool "Group scheduling for SCHED_RR/FIFO"
943 depends on EXPERIMENTAL
944 depends on CGROUP_SCHED
945 default n
946 help
947 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +0800948 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +0100949 schedule realtime tasks for non-root users until you allocate
950 realtime bandwidth for them.
951 See Documentation/scheduler/sched-rt-group.txt for more information.
952
953endif #CGROUP_SCHED
954
Vivek Goyalafc24d42010-04-26 19:27:56 +0200955config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -0800956 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700957 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +0200958 default n
959 ---help---
960 Generic block IO controller cgroup interface. This is the common
961 cgroup interface which should be used by various IO controlling
962 policies.
963
964 Currently, CFQ IO scheduler uses it to recognize task groups and
965 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -0400966 to such task groups. It is also used by bio throttling logic in
967 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200968
969 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -0400970 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +0000971 enabling proportional weight division of disk bandwidth in CFQ, set
972 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +0000973 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +0200974
975 See Documentation/cgroups/blkio-controller.txt for more information.
976
977config DEBUG_BLK_CGROUP
978 bool "Enable Block IO controller debugging"
979 depends on BLK_CGROUP
980 default n
981 ---help---
982 Enable some debugging help. Currently it exports additional stat
983 files in a cgroup which can be useful for debugging.
984
Li Zefan23964d22009-01-15 13:50:58 -0800985endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800986
Cyrill Gorcunov067bce12012-01-12 17:20:49 -0800987config CHECKPOINT_RESTORE
988 bool "Checkpoint/restore support" if EXPERT
989 default n
990 help
991 Enables additional kernel features in a sake of checkpoint/restore.
992 In particular it adds auxiliary prctl codes to setup process text,
993 data and heap segment sizes, and a few additional /proc filesystem
994 entries.
995
996 If unsure, say N here.
997
Daniel Lezcano8dd2a822010-10-27 15:34:38 -0700998menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -0800999 bool "Namespaces support" if EXPERT
1000 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001001 help
1002 Provides the way to make tasks work with different objects using
1003 the same id. For example same IPC id may refer to different objects
1004 or same user id or pid may refer to different tasks when used in
1005 different namespaces.
1006
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001007if NAMESPACES
1008
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001009config UTS_NS
1010 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001011 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001012 help
1013 In this namespace tasks see different info provided with the
1014 uname() system call
1015
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001016config IPC_NS
1017 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001018 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001019 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001020 help
1021 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001022 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001023
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001024config USER_NS
1025 bool "User namespace (EXPERIMENTAL)"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001026 depends on EXPERIMENTAL
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001027 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001028 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001029
Eric W. Biederman5673a942011-11-17 10:23:55 -08001030 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001031 help
1032 This allows containers, i.e. vservers, to use user namespaces
1033 to provide different user info for different servers.
1034 If unsure, say N.
1035
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001036config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001037 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001038 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001039 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001040 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001041 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001042 pid namespaces. This is a building block of containers.
1043
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001044config NET_NS
1045 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001046 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001047 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001048 help
1049 Allow user space to create what appear to be multiple instances
1050 of the network stack.
1051
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001052endif # NAMESPACES
1053
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001054config UIDGID_CONVERTED
1055 # True if all of the selected software conmponents are known
1056 # to have uid_t and gid_t converted to kuid_t and kgid_t
1057 # where appropriate and are otherwise safe to use with
1058 # the user namespace.
1059 bool
1060 default y
1061
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001062 # Networking
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001063 depends on NET_9P = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001064
1065 # Filesystems
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001066 depends on 9P_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001067 depends on AFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001068 depends on CEPH_FS = n
1069 depends on CIFS = n
1070 depends on CODA_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001071 depends on GFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001072 depends on NCP_FS = n
1073 depends on NFSD = n
1074 depends on NFS_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001075 depends on OCFS2_FS = n
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001076 depends on XFS_FS = n
1077
Eric W. Biederman5673a942011-11-17 10:23:55 -08001078config UIDGID_STRICT_TYPE_CHECKS
1079 bool "Require conversions between uid/gids and their internal representation"
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001080 depends on UIDGID_CONVERTED
Eric W. Biederman5673a942011-11-17 10:23:55 -08001081 default n
1082 help
1083 While the nececessary conversions are being added to all subsystems this option allows
1084 the code to continue to build for unconverted subsystems.
1085
1086 Say Y here if you want the strict type checking enabled
1087
Mike Galbraith5091faa2010-11-30 14:18:03 +01001088config SCHED_AUTOGROUP
1089 bool "Automatic process group scheduling"
1090 select EVENTFD
1091 select CGROUPS
1092 select CGROUP_SCHED
1093 select FAIR_GROUP_SCHED
1094 help
1095 This option optimizes the scheduler for common desktop workloads by
1096 automatically creating and populating task groups. This separation
1097 of workloads isolates aggressive CPU burners (like build jobs) from
1098 desktop applications. Task group autogeneration is currently based
1099 upon task session.
1100
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001101config MM_OWNER
1102 bool
1103
1104config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001105 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001106 depends on SYSFS
1107 default n
1108 help
1109 This option adds code that switches the layout of the "block" class
1110 devices, to not show up in /sys/class/block/, but only in
1111 /sys/block/.
1112
1113 This switch is only active when the sysfs.deprecated=1 boot option is
1114 passed or the SYSFS_DEPRECATED_V2 option is set.
1115
1116 This option allows new kernels to run on old distributions and tools,
1117 which might get confused by /sys/class/block/. Since 2007/2008 all
1118 major distributions and tools handle this just fine.
1119
1120 Recent distributions and userspace tools after 2009/2010 depend on
1121 the existence of /sys/class/block/, and will not work with this
1122 option enabled.
1123
1124 Only if you are using a new kernel on an old distribution, you might
1125 need to say Y here.
1126
1127config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001128 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001129 default n
1130 depends on SYSFS
1131 depends on SYSFS_DEPRECATED
1132 help
1133 Enable deprecated sysfs by default.
1134
1135 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1136 option.
1137
1138 Only if you are using a new kernel on an old distribution, you might
1139 need to say Y here. Even then, odds are you would not need it
1140 enabled, you can always pass the boot option if absolutely necessary.
1141
1142config RELAY
1143 bool "Kernel->user space relay support (formerly relayfs)"
1144 help
1145 This option enables support for relay interface support in
1146 certain file systems (such as debugfs).
1147 It is designed to provide an efficient mechanism for tools and
1148 facilities to relay large amounts of data from kernel space to
1149 user space.
1150
1151 If unsure, say N.
1152
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001153config BLK_DEV_INITRD
1154 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1155 depends on BROKEN || !FRV
1156 help
1157 The initial RAM filesystem is a ramfs which is loaded by the
1158 boot loader (loadlin or lilo) and that is mounted as root
1159 before the normal boot procedure. It is typically used to
1160 load modules needed to mount the "real" root file system,
1161 etc. See <file:Documentation/initrd.txt> for details.
1162
1163 If RAM disk support (BLK_DEV_RAM) is also included, this
1164 also enables initial RAM disk (initrd) support and adds
1165 15 Kbytes (more on some other architectures) to the kernel size.
1166
1167 If unsure say Y.
1168
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001169if BLK_DEV_INITRD
1170
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001171source "usr/Kconfig"
1172
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001173endif
1174
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001175config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001176 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001177 help
1178 Enabling this option will pass "-Os" instead of "-O2" to gcc
1179 resulting in a smaller kernel.
1180
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001181 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001182
Randy Dunlap08470622006-09-30 23:28:13 -07001183config SYSCTL
1184 bool
1185
Randy Dunlapb943c462009-03-10 12:55:46 -07001186config ANON_INODES
1187 bool
1188
David Rientjes6a108a12011-01-20 14:44:16 -08001189menuconfig EXPERT
1190 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001191 # Unhide debug options, to make the on-by-default options visible
1192 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 help
1194 This option allows certain base kernel options and settings
1195 to be disabled or tweaked. This is for specialized
1196 environments which can tolerate a "non-standard" kernel.
1197 Only use this if you really know what you are doing.
1198
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001199config HAVE_UID16
1200 bool
1201
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001202config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001203 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001204 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001205 default y
1206 help
1207 This enables the legacy 16-bit UID syscall wrappers.
1208
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001209config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001210 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001211 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001212 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001213 select SYSCTL
1214 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001215 sys_sysctl uses binary paths that have been found challenging
1216 to properly maintain and use. The interface in /proc/sys
1217 using paths with ascii names is now the primary path to this
1218 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001219
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001220 Almost nothing using the binary sysctl interface so if you are
1221 trying to save some space it is probably safe to disable this,
1222 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001223
WANG Congc736de62011-11-02 13:39:25 -07001224 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001225
Catalin Marinas7ac57a82012-10-08 16:28:16 -07001226config SYSCTL_EXCEPTION_TRACE
1227 bool
1228 help
1229 Enable support for /proc/sys/debug/exception-trace.
1230
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001232 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 default y
1234 help
1235 Say Y here to let the kernel print out symbolic crash information and
1236 symbolic stack backtraces. This increases the size of the kernel
1237 somewhat, as all symbols have to be loaded into the kernel image.
1238
1239config KALLSYMS_ALL
1240 bool "Include all symbols in kallsyms"
1241 depends on DEBUG_KERNEL && KALLSYMS
1242 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001243 Normally kallsyms only contains the symbols of functions for nicer
1244 OOPS messages and backtraces (i.e., symbols from the text and inittext
1245 sections). This is sufficient for most cases. And only in very rare
1246 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1247 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001249 This option makes sure that all symbols are loaded into the kernel
1250 image (i.e., symbols from all sections) in cost of increased kernel
1251 size (depending on the kernel configuration, it may be 300KiB or
1252 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001254 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001255
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001256config HOTPLUG
Greg Kroah-Hartman45f035a2012-09-04 17:01:08 -07001257 def_bool y
Greg Kroah-Hartman712f47c2005-11-16 11:27:07 -08001258
Matt Mackalld59745c2005-05-01 08:59:02 -07001259config PRINTK
1260 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001261 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001262 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001263 help
1264 This option enables normal printk support. Removing it
1265 eliminates most of the message strings from the kernel image
1266 and makes the kernel more or less silent. As this makes it
1267 very difficult to diagnose system problems, saying N here is
1268 strongly discouraged.
1269
Matt Mackallc8538a72005-05-01 08:59:01 -07001270config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001271 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001272 default y
1273 help
1274 Disabling this option eliminates support for BUG and WARN, reducing
1275 the size of your kernel image and potentially quietly ignoring
1276 numerous fatal conditions. You should only consider disabling this
1277 option for embedded systems with no facilities for reporting errors.
1278 Just say Y.
1279
Matt Mackall708e9a72006-01-08 01:05:25 -08001280config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001281 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001282 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001283 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001284 help
1285 Enable support for generating core dumps. Disabling saves about 4k.
1286
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001287
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001288config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001289 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001290 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001291 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001292 default y
1293 help
1294 This option allows to disable the internal PC-Speaker
1295 support, saving some memory.
1296
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001297config HAVE_PCSPKR_PLATFORM
1298 bool
1299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300config BASE_FULL
1301 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001302 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 help
1304 Disabling this option reduces the size of miscellaneous core
1305 kernel data structures. This saves memory on small machines,
1306 but may reduce performance.
1307
1308config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001309 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001311 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 help
1313 Disabling this option will cause the kernel to be built without
1314 support for "fast userspace mutexes". The resulting kernel may not
1315 run glibc-based applications correctly.
1316
1317config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001318 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001320 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 help
1322 Disabling this option will cause the kernel to be built without
1323 support for epoll family of system calls.
1324
Davide Libenzifba2afa2007-05-10 22:23:13 -07001325config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001326 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001327 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001328 default y
1329 help
1330 Enable the signalfd() system call that allows to receive signals
1331 on a file descriptor.
1332
1333 If unsure, say Y.
1334
Davide Libenzib215e282007-05-10 22:23:16 -07001335config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001336 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001337 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001338 default y
1339 help
1340 Enable the timerfd() system call that allows to receive timer
1341 events on a file descriptor.
1342
1343 If unsure, say Y.
1344
Davide Libenzie1ad7462007-05-10 22:23:19 -07001345config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001346 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001347 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001348 default y
1349 help
1350 Enable the eventfd() system call that allows to receive both
1351 kernel notification (ie. KAIO) or userspace notifications.
1352
1353 If unsure, say Y.
1354
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001356 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 default y
1358 depends on MMU
1359 help
1360 The shmem is an internal filesystem used to manage shared memory.
1361 It is backed by swap and manages resource limits. It is also exported
1362 to userspace as tmpfs if TMPFS is enabled. Disabling this
1363 option replaces shmem and tmpfs with the much simpler ramfs code,
1364 which may be appropriate on small systems without swap.
1365
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001366config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001367 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001368 default y
1369 help
1370 This option enables POSIX asynchronous I/O which may by used
1371 by some high performance threaded applications. Disabling
1372 this option saves about 7k.
1373
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001374config EMBEDDED
1375 bool "Embedded system"
1376 select EXPERT
1377 help
1378 This option should be enabled if compiling the kernel for
1379 an embedded system so certain expert options are available
1380 for configuration.
1381
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001382config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001383 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001384 help
1385 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001386
Peter Zijlstra906010b2009-09-21 16:08:49 +02001387config PERF_USE_VMALLOC
1388 bool
1389 help
1390 See tools/perf/design.txt for details
1391
Ingo Molnar57c0c152009-09-21 12:20:38 +02001392menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001393
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001394config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001395 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001396 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001397 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001398 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001399 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001400 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001401 Enable kernel support for various performance events provided
1402 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001403
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001404 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001405 use of generic tracepoints.
1406
1407 Most modern CPUs support performance events via performance
1408 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001409 types of hw events: such as instructions executed, cachemisses
1410 suffered, or branches mis-predicted - without slowing down the
1411 kernel or applications. These registers can also trigger interrupts
1412 when a threshold number of events have passed - and can thus be
1413 used to profile the code that runs on that CPU.
1414
Ingo Molnar57c0c152009-09-21 12:20:38 +02001415 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001416 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001417 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001418 provides per task and per CPU counters, and it provides event
1419 capabilities on top of those.
1420
1421 Say Y if unsure.
1422
Peter Zijlstra906010b2009-09-21 16:08:49 +02001423config DEBUG_PERF_USE_VMALLOC
1424 default n
1425 bool "Debug: use vmalloc to back perf mmap() buffers"
1426 depends on PERF_EVENTS && DEBUG_KERNEL
1427 select PERF_USE_VMALLOC
1428 help
1429 Use vmalloc memory to back perf mmap() buffers.
1430
1431 Mostly useful for debugging the vmalloc code on platforms
1432 that don't require it.
1433
1434 Say N if unsure.
1435
Thomas Gleixner0793a612008-12-04 20:12:29 +01001436endmenu
1437
Christoph Lameterf8891e52006-06-30 01:55:45 -07001438config VM_EVENT_COUNTERS
1439 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001440 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001441 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001442 VM event counters are needed for event counts to be shown.
1443 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001444 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001445 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001446
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001447config PCI_QUIRKS
1448 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001449 bool "Enable PCI quirk workarounds" if EXPERT
Geert Uytterhoeven61cfc7e2008-10-22 08:53:25 +02001450 depends on PCI
Thomas Petazzoni3d137312008-08-19 10:28:24 +02001451 help
1452 This enables workarounds for various PCI chipset
1453 bugs/quirks. Disable this only if your target machine is
1454 unaffected by PCI quirks.
1455
Christoph Lameter41ecc552007-05-09 02:32:44 -07001456config SLUB_DEBUG
1457 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001458 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001459 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001460 help
1461 SLUB has extensive debug support features. Disabling these can
1462 result in significant savings in code size. This also disables
1463 SLUB sysfs support. /sys/slab will not exist and there will be
1464 no support for cache validation etc.
1465
Randy Dunlapb943c462009-03-10 12:55:46 -07001466config COMPAT_BRK
1467 bool "Disable heap randomization"
1468 default y
1469 help
1470 Randomizing heap placement makes heap exploits harder, but it
1471 also breaks ancient binaries (including anything libc5 based).
1472 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001473 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001474 /proc/sys/kernel/randomize_va_space to 2.
1475
1476 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1477
Christoph Lameter81819f02007-05-06 14:49:36 -07001478choice
1479 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001480 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001481 help
1482 This option allows to select a slab allocator.
1483
1484config SLAB
1485 bool "SLAB"
1486 help
1487 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001488 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001489 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001490
1491config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001492 bool "SLUB (Unqueued Allocator)"
1493 help
1494 SLUB is a slab allocator that minimizes cache line usage
1495 instead of managing queues of cached objects (SLAB approach).
1496 Per cpu caching is realized using slabs of objects instead
1497 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001498 and has enhanced diagnostics. SLUB is the default choice for
1499 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001500
1501config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001502 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001503 bool "SLOB (Simple Allocator)"
1504 help
Matt Mackall37291452008-02-04 22:29:38 -08001505 SLOB replaces the stock allocator with a drastically simpler
1506 allocator. SLOB is generally more space efficient but
1507 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001508
1509endchoice
1510
Jie Zhangea637632009-12-14 18:00:02 -08001511config MMAP_ALLOW_UNINITIALIZED
1512 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001513 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001514 default n
1515 help
1516 Normally, and according to the Linux spec, anonymous memory obtained
1517 from mmap() has it's contents cleared before it is passed to
1518 userspace. Enabling this config option allows you to request that
1519 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1520 providing a huge performance boost. If this option is not enabled,
1521 then the flag will be ignored.
1522
1523 This is taken advantage of by uClibc's malloc(), and also by
1524 ELF-FDPIC binfmt's brk and stack allocator.
1525
1526 Because of the obvious security issues, this option should only be
1527 enabled on embedded devices where you control what is run in
1528 userspace. Since that isn't generally a problem on no-MMU systems,
1529 it is normally safe to say Y here.
1530
1531 See Documentation/nommu-mmap.txt for more information.
1532
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001533config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001534 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001535 help
1536 Say Y here to enable the extended profiling support mechanisms used
1537 by profilers such as OProfile.
1538
Ingo Molnar5f87f112008-07-23 14:15:22 +02001539#
1540# Place an empty function call at each tracepoint site. Can be
1541# dynamically changed for a probe function.
1542#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001543config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001544 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001545
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001546source "arch/Kconfig"
1547
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548endmenu # General setup
1549
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001550config HAVE_GENERIC_DMA_COHERENT
1551 bool
1552 default n
1553
Linus Torvalds158a9622008-01-02 13:04:48 -08001554config SLABINFO
1555 bool
1556 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001557 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001558 default y
1559
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001560config RT_MUTEXES
1561 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001562
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563config BASE_SMALL
1564 int
1565 default 0 if BASE_FULL
1566 default 1 if !BASE_FULL
1567
Jan Engelhardt66da5732007-07-15 23:39:29 -07001568menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 bool "Enable loadable module support"
1570 help
1571 Kernel modules are small pieces of compiled code which can
1572 be inserted in the running kernel, rather than being
1573 permanently built into the kernel. You use the "modprobe"
1574 tool to add (and sometimes remove) them. If you say Y here,
1575 many parts of the kernel can be built as modules (by
1576 answering M instead of Y where indicated): this is most
1577 useful for infrequently used options which are not required
1578 for booting. For more information, see the man pages for
1579 modprobe, lsmod, modinfo, insmod and rmmod.
1580
1581 If you say Y here, you will need to run "make
1582 modules_install" to put the modules under /lib/modules/
1583 where modprobe can find them (you may need to be root to do
1584 this).
1585
1586 If unsure, say Y.
1587
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001588if MODULES
1589
Linus Torvalds826e4502008-05-04 17:04:16 -07001590config MODULE_FORCE_LOAD
1591 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001592 default n
1593 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001594 Allow loading of modules without version information (ie. modprobe
1595 --force). Forced module loading sets the 'F' (forced) taint flag and
1596 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001597
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598config MODULE_UNLOAD
1599 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 help
1601 Without this option you will not be able to unload any
1602 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001603 anyway), which makes your kernel smaller, faster
1604 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605
1606config MODULE_FORCE_UNLOAD
1607 bool "Forced module unloading"
1608 depends on MODULE_UNLOAD && EXPERIMENTAL
1609 help
1610 This option allows you to force a module to unload, even if the
1611 kernel believes it is unsafe: the kernel will remove the module
1612 without waiting for anyone to stop using it (using the -f option to
1613 rmmod). This is mainly for kernel developers and desperate users.
1614 If unsure, say N.
1615
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001617 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618 help
1619 Usually, you have to use modules compiled with your kernel.
1620 Saying Y here makes it sometimes possible to use modules
1621 compiled for different kernels, by adding enough information
1622 to the modules to (hopefully) spot any changes which would
1623 make them incompatible with the kernel you are running. If
1624 unsure, say N.
1625
1626config MODULE_SRCVERSION_ALL
1627 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 help
1629 Modules which contain a MODULE_VERSION get an extra "srcversion"
1630 field inserted into their modinfo section, which contains a
1631 sum of the source files which made it. This helps maintainers
1632 see exactly which source was used to build a module (since
1633 others sometimes change the module source without updating
1634 the version). With this option, such a "srcversion" field
1635 will be created for all modules. If unsure, say N.
1636
Rusty Russell106a4ee2012-09-26 10:09:40 +01001637config MODULE_SIG
1638 bool "Module signature verification"
1639 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001640 select KEYS
1641 select CRYPTO
1642 select ASYMMETRIC_KEY_TYPE
1643 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1644 select PUBLIC_KEY_ALGO_RSA
1645 select ASN1
1646 select OID_REGISTRY
1647 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001648 help
1649 Check modules for valid signatures upon load: the signature
1650 is simply appended to the module. For more information see
1651 Documentation/module-signing.txt.
1652
David Howellsea0b6dc2012-09-26 10:09:50 +01001653 !!!WARNING!!! If you enable this option, you MUST make sure that the
1654 module DOES NOT get stripped after being signed. This includes the
1655 debuginfo strip done by some packagers (such as rpmbuild) and
1656 inclusion into an initramfs that wants the module size reduced.
1657
Rusty Russell106a4ee2012-09-26 10:09:40 +01001658config MODULE_SIG_FORCE
1659 bool "Require modules to be validly signed"
1660 depends on MODULE_SIG
1661 help
1662 Reject unsigned modules or signed modules for which we don't have a
1663 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001664
1665choice
1666 prompt "Which hash algorithm should modules be signed with?"
1667 depends on MODULE_SIG
1668 help
1669 This determines which sort of hashing algorithm will be used during
1670 signature generation. This algorithm _must_ be built into the kernel
1671 directly so that signature verification can take place. It is not
1672 possible to load a signed module containing the algorithm to check
1673 the signature on that module.
1674
1675config MODULE_SIG_SHA1
1676 bool "Sign modules with SHA-1"
1677 select CRYPTO_SHA1
1678
1679config MODULE_SIG_SHA224
1680 bool "Sign modules with SHA-224"
1681 select CRYPTO_SHA256
1682
1683config MODULE_SIG_SHA256
1684 bool "Sign modules with SHA-256"
1685 select CRYPTO_SHA256
1686
1687config MODULE_SIG_SHA384
1688 bool "Sign modules with SHA-384"
1689 select CRYPTO_SHA512
1690
1691config MODULE_SIG_SHA512
1692 bool "Sign modules with SHA-512"
1693 select CRYPTO_SHA512
1694
1695endchoice
1696
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001697endif # MODULES
1698
Rusty Russell98a79d62008-12-13 21:19:41 +10301699config INIT_ALL_POSSIBLE
1700 bool
1701 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301702 Back when each arch used to define their own cpu_online_mask and
1703 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301704 with all 1s, and others with all 0s. When they were centralised,
1705 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001706 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301707
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708config STOP_MACHINE
1709 bool
1710 default y
1711 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1712 help
1713 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001714
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001715source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001716
1717config PREEMPT_NOTIFIERS
1718 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001719
Steffen Klassert16295be2010-01-06 19:47:10 +11001720config PADATA
1721 depends on SMP
1722 bool
1723
Andi Kleen754b7b62012-10-04 17:11:27 -07001724# Can be selected by architectures with broken toolchains
1725# that get confused by correct const<->read_only section
1726# mappings
1727config BROKEN_RODATA
1728 bool
1729
David Howells4520c6a2012-09-21 23:31:13 +01001730config ASN1
1731 tristate
1732 help
1733 Build a simple ASN.1 grammar compiler that produces a bytecode output
1734 that can be interpreted by the ASN.1 stream decoder and used to
1735 inform it as to what tags are to be expected in a stream and what
1736 functions to call on what tags.
1737
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001738source "kernel/Kconfig.locks"