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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070031config BROKEN
32 bool
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34config BROKEN_ON_SMP
35 bool
36 depends on BROKEN || !SMP
37 default y
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039config INIT_ENV_ARG_LIMIT
40 int
Adrian Bunkdd673bc2006-06-30 01:55:51 -070041 default 32 if !UML
42 default 128 if UML
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 help
Randy Dunlap34ad92c2005-10-30 15:01:46 -080044 Maximum of each of the number of arguments and environment
45 variables passed to init from the kernel command line.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Roland McGrath84336462009-12-21 16:24:06 -080048config CROSS_COMPILE
49 string "Cross-compiler tool prefix"
50 help
51 Same as running 'make CROSS_COMPILE=prefix-' but stored for
52 default make runs in this kernel build directory. You don't
53 need to set this unless you want the configured kernel build
54 directory to select the cross-compiler automatically.
55
Jiri Slaby4bb16672013-05-22 10:56:24 +020056config COMPILE_TEST
57 bool "Compile also drivers which will not load"
58 default n
59 help
60 Some drivers can be compiled on a different platform than they are
61 intended to be run on. Despite they cannot be loaded there (or even
62 when they load they cannot be used due to missing HW support),
63 developers still, opposing to distributors, might want to build such
64 drivers to compile-test them.
65
66 If you are a developer and want to build everything available, say Y
67 here. If you are a user/distributor, say N here to exclude useless
68 drivers to be distributed.
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070config LOCALVERSION
71 string "Local version - append to kernel release"
72 help
73 Append an extra string to the end of your kernel version.
74 This will show up when you type uname, for example.
75 The string you set here will be appended after the contents of
76 any files with a filename matching localversion* in your
77 object and source tree, in that order. Your total string can
78 be a maximum of 64 characters.
79
Ryan Andersonaaebf432005-07-31 04:57:49 -040080config LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
82 default y
83 help
84 This will try to automatically determine if the current tree is a
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020085 release tree by looking for git tags that belong to the current
86 top of tree revision.
Ryan Andersonaaebf432005-07-31 04:57:49 -040087
88 A string of the format -gxxxxxxxx will be added to the localversion
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020089 if a git-based tree is found. The string generated by this will be
Ryan Andersonaaebf432005-07-31 04:57:49 -040090 appended after any matching localversion* files, and after the value
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020091 set in CONFIG_LOCALVERSION.
Ryan Andersonaaebf432005-07-31 04:57:49 -040092
Robert P. J. Day6e5a5422007-05-01 23:08:11 +020093 (The actual string used here is the first eight characters produced
94 by running the command:
95
96 $ git rev-parse --verify HEAD
97
98 which is done within the script "scripts/setlocalversion".)
Ryan Andersonaaebf432005-07-31 04:57:49 -040099
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800100config HAVE_KERNEL_GZIP
101 bool
102
103config HAVE_KERNEL_BZIP2
104 bool
105
106config HAVE_KERNEL_LZMA
107 bool
108
Lasse Collin3ebe1242011-01-12 17:01:23 -0800109config HAVE_KERNEL_XZ
110 bool
111
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800112config HAVE_KERNEL_LZO
113 bool
114
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700115config HAVE_KERNEL_LZ4
116 bool
117
Alain Knaff30d65db2009-01-04 22:46:17 +0100118choice
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800119 prompt "Kernel compression mode"
120 default KERNEL_GZIP
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700121 depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800122 help
Alain Knaff30d65db2009-01-04 22:46:17 +0100123 The linux kernel is a kind of self-extracting executable.
124 Several compression algorithms are available, which differ
125 in efficiency, compression and decompression speed.
126 Compression speed is only relevant when building a kernel.
127 Decompression speed is relevant at each boot.
128
129 If you have any problems with bzip2 or lzma compressed
130 kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
131 version of this functionality (bzip2 only), for 2.4, was
132 supplied by Christian Ludwig)
133
134 High compression options are mostly useful for users, who
135 are low on disk space (embedded systems), but for whom ram
136 size matters less.
137
138 If in doubt, select 'gzip'
139
140config KERNEL_GZIP
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800141 bool "Gzip"
142 depends on HAVE_KERNEL_GZIP
143 help
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800144 The old and tried gzip compression. It provides a good balance
145 between compression ratio and decompression speed.
Alain Knaff30d65db2009-01-04 22:46:17 +0100146
147config KERNEL_BZIP2
148 bool "Bzip2"
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800149 depends on HAVE_KERNEL_BZIP2
Alain Knaff30d65db2009-01-04 22:46:17 +0100150 help
151 Its compression ratio and speed is intermediate.
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700152 Decompression speed is slowest among the choices. The kernel
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800153 size is about 10% smaller with bzip2, in comparison to gzip.
154 Bzip2 uses a large amount of memory. For modern kernels you
155 will need at least 8MB RAM or more for booting.
Alain Knaff30d65db2009-01-04 22:46:17 +0100156
157config KERNEL_LZMA
H. Peter Anvin2e9f3bd2009-01-04 15:41:25 -0800158 bool "LZMA"
159 depends on HAVE_KERNEL_LZMA
160 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700161 This compression algorithm's ratio is best. Decompression speed
162 is between gzip and bzip2. Compression is slowest.
163 The kernel size is about 33% smaller with LZMA in comparison to gzip.
Alain Knaff30d65db2009-01-04 22:46:17 +0100164
Lasse Collin3ebe1242011-01-12 17:01:23 -0800165config KERNEL_XZ
166 bool "XZ"
167 depends on HAVE_KERNEL_XZ
168 help
169 XZ uses the LZMA2 algorithm and instruction set specific
170 BCJ filters which can improve compression ratio of executable
171 code. The size of the kernel is about 30% smaller with XZ in
172 comparison to gzip. On architectures for which there is a BCJ
173 filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
174 will create a few percent smaller kernel than plain LZMA.
175
176 The speed is about the same as with LZMA: The decompression
177 speed of XZ is better than that of bzip2 but worse than gzip
178 and LZO. Compression is slow.
179
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800180config KERNEL_LZO
181 bool "LZO"
182 depends on HAVE_KERNEL_LZO
183 help
Randy Dunlap0a4dd352012-05-31 16:26:46 -0700184 Its compression ratio is the poorest among the choices. The kernel
Stephan Sperber681b3042010-07-14 11:23:08 +0200185 size is about 10% bigger than gzip; however its speed
Albin Tonnerre7dd65fe2010-01-08 14:42:42 -0800186 (both compression and decompression) is the fastest.
187
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700188config KERNEL_LZ4
189 bool "LZ4"
190 depends on HAVE_KERNEL_LZ4
191 help
192 LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
193 A preliminary version of LZ4 de/compression tool is available at
194 <https://code.google.com/p/lz4/>.
195
196 Its compression ratio is worse than LZO. The size of the kernel
197 is about 8% bigger than LZO. But the decompression speed is
198 faster than LZO.
199
Alain Knaff30d65db2009-01-04 22:46:17 +0100200endchoice
201
Josh Triplettbd5dc172011-06-15 15:08:28 -0700202config DEFAULT_HOSTNAME
203 string "Default hostname"
204 default "(none)"
205 help
206 This option determines the default system hostname before userspace
207 calls sethostname(2). The kernel traditionally uses "(none)" here,
208 but you may wish to use a different default here to make a minimal
209 system more usable with less configuration.
210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211config SWAP
212 bool "Support for paging of anonymous memory (swap)"
David Howells93614012006-09-30 20:45:40 +0200213 depends on MMU && BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 default y
215 help
216 This option allows you to choose whether you want to have support
Jesper Juhl92c35042006-01-15 02:40:08 +0100217 for so called swap devices or swap files in your kernel that are
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 used to provide more virtual memory than the actual RAM present
219 in your computer. If unsure say Y.
220
221config SYSVIPC
222 bool "System V IPC"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 ---help---
224 Inter Process Communication is a suite of library functions and
225 system calls which let processes (running programs) synchronize and
226 exchange information. It is generally considered to be a good thing,
227 and some programs won't run unless you say Y here. In particular, if
228 you want to run the DOS emulator dosemu under Linux (read the
229 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
230 you'll need to say Y here.
231
232 You can find documentation about IPC with "info ipc" and also in
233 section 6.4 of the Linux Programmer's Guide, available from
234 <http://www.tldp.org/guides.html>.
235
Eric W. Biedermana5494dc2007-02-14 00:34:06 -0800236config SYSVIPC_SYSCTL
237 bool
238 depends on SYSVIPC
239 depends on SYSCTL
240 default y
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242config POSIX_MQUEUE
243 bool "POSIX Message Queues"
Kees Cook19c92392012-10-02 11:19:29 -0700244 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 ---help---
246 POSIX variant of message queues is a part of IPC. In POSIX message
247 queues every message has a priority which decides about succession
248 of receiving it by a process. If you want to compile and run
249 programs written e.g. for Solaris with use of its POSIX message
Robert P. J. Dayb0e37652007-05-09 07:25:13 +0200250 queues (functions mq_*) say Y here.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 POSIX message queues are visible as a filesystem called 'mqueue'
253 and can be mounted somewhere if you want to do filesystem
254 operations on message queues.
255
256 If unsure, say Y.
257
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -0700258config POSIX_MQUEUE_SYSCTL
259 bool
260 depends on POSIX_MQUEUE
261 depends on SYSCTL
262 default y
263
Aneesh Kumar K.V990d6c22011-01-29 18:43:26 +0530264config FHANDLE
265 bool "open by fhandle syscalls"
266 select EXPORTFS
267 help
268 If you say Y here, a user level program will be able to map
269 file names to handle and then later use the handle for
270 different file system operations. This is useful in implementing
271 userspace file servers, which now track files using handles instead
272 of names. The handle would remain the same even if file names
273 get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
274 syscalls.
275
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276config AUDIT
277 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100278 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 help
280 Enable auditing infrastructure that can be used with another
281 kernel subsystem, such as SELinux (which requires this for
282 logging of avc messages output). Does not do system-call
283 auditing without CONFIG_AUDITSYSCALL.
284
285config AUDITSYSCALL
286 bool "Enable system-call auditing support"
Helge Deller527973c2013-10-15 19:25:46 +0200287 depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 default y if SECURITY_SELINUX
289 help
290 Enable low-overhead system-call auditing infrastructure that
291 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500292 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Eric Paris939a67f2009-12-17 20:12:06 -0500294config AUDIT_WATCH
295 def_bool y
296 depends on AUDITSYSCALL
297 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
Al Viro74c3cbe2007-07-22 08:04:18 -0400299config AUDIT_TREE
300 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400301 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500302 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400303
Eric Paris633b4542012-01-03 14:23:08 -0500304config AUDIT_LOGINUID_IMMUTABLE
305 bool "Make audit loginuid immutable"
306 depends on AUDIT
307 help
Linus Torvaldsf429ee32012-01-17 16:06:51 -0800308 The config option toggles if a task setting its loginuid requires
Eric Paris633b4542012-01-03 14:23:08 -0500309 CAP_SYS_AUDITCONTROL or if that task should require no special permissions
310 but should instead only allow setting its loginuid if it was never
311 previously set. On systems which use systemd or a similar central
312 process to restart login services this should be set to true. On older
313 systems in which an admin would typically have to directly stop and
314 start processes this should be set to false. Setting this to true allows
315 one to drop potentially dangerous capabilites from the login tasks,
316 but may not be backwards compatible with older init systems.
317
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000318source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200319source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000320
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200321menu "CPU/Task time and stats accounting"
322
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200323config VIRT_CPU_ACCOUNTING
324 bool
325
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200326choice
327 prompt "Cputime accounting"
328 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100329 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200330
331# Kind of a stub config for the pure tick based cputime accounting
332config TICK_CPU_ACCOUNTING
333 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200334 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200335 help
336 This is the basic tick based cputime accounting that maintains
337 statistics about user, system and idle time spent on per jiffies
338 granularity.
339
340 If unsure, say Y.
341
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200342config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200343 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200344 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200345 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200346 help
347 Select this option to enable more accurate task and CPU time
348 accounting. This is done by reading a CPU counter on each
349 kernel entry and exit and on transitions within the kernel
350 between system, softirq and hardirq state, so there is a
351 small performance impact. In the case of s390 or IBM POWER > 5,
352 this also enables accounting of stolen time on logically-partitioned
353 systems.
354
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200355config VIRT_CPU_ACCOUNTING_GEN
356 bool "Full dynticks CPU time accounting"
357 depends on HAVE_CONTEXT_TRACKING && 64BIT
358 select VIRT_CPU_ACCOUNTING
359 select CONTEXT_TRACKING
360 help
361 Select this option to enable task and CPU time accounting on full
362 dynticks systems. This accounting is implemented by watching every
363 kernel-user boundaries using the context tracking subsystem.
364 The accounting is thus performed at the expense of some significant
365 overhead.
366
367 For now this is only useful if you are working on the full
368 dynticks subsystem development.
369
370 If unsure, say N.
371
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200372config IRQ_TIME_ACCOUNTING
373 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200374 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200375 help
376 Select this option to enable fine granularity task irq time
377 accounting. This is done by reading a timestamp on each
378 transitions between softirq and hardirq state, so there can be a
379 small performance impact.
380
381 If in doubt, say N here.
382
383endchoice
384
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200385config BSD_PROCESS_ACCT
386 bool "BSD Process Accounting"
387 help
388 If you say Y here, a user level program will be able to instruct the
389 kernel (via a special system call) to write process accounting
390 information to a file: whenever a process exits, information about
391 that process will be appended to the file by the kernel. The
392 information includes things such as creation time, owning user,
393 command name, memory usage, controlling terminal etc. (the complete
394 list is in the struct acct in <file:include/linux/acct.h>). It is
395 up to the user level program to do useful things with this
396 information. This is generally a good idea, so say Y.
397
398config BSD_PROCESS_ACCT_V3
399 bool "BSD Process Accounting version 3 file format"
400 depends on BSD_PROCESS_ACCT
401 default n
402 help
403 If you say Y here, the process accounting information is written
404 in a new file format that also logs the process IDs of each
405 process and it's parent. Note that this file format is incompatible
406 with previous v0/v1/v2 file formats, so you will need updated tools
407 for processing it. A preliminary version of these tools is available
408 at <http://www.gnu.org/software/acct/>.
409
410config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700411 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200412 depends on NET
413 default n
414 help
415 Export selected statistics for tasks/processes through the
416 generic netlink interface. Unlike BSD process accounting, the
417 statistics are available during the lifetime of tasks/processes as
418 responses to commands. Like BSD accounting, they are sent to user
419 space on task exit.
420
421 Say N if unsure.
422
423config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700424 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200425 depends on TASKSTATS
426 help
427 Collect information on time spent by a task waiting for system
428 resources like cpu, synchronous block I/O completion and swapping
429 in pages. Such statistics can help in setting a task's priorities
430 relative to other tasks for cpu, io, rss limits etc.
431
432 Say N if unsure.
433
434config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700435 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200436 depends on TASKSTATS
437 help
438 Collect extended task accounting data and send the data
439 to userland for processing over the taskstats interface.
440
441 Say N if unsure.
442
443config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700444 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200445 depends on TASK_XACCT
446 help
447 Collect information on the number of bytes of storage I/O which this
448 task has caused.
449
450 Say N if unsure.
451
452endmenu # "CPU/Task time and stats accounting"
453
Mike Travisc903ff82009-01-15 12:28:29 -0800454menu "RCU Subsystem"
455
456choice
457 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700458 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800459
Mike Travisc903ff82009-01-15 12:28:29 -0800460config TREE_RCU
461 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700462 depends on !PREEMPT && SMP
Steven Rostedt016a8d52013-05-28 17:32:53 -0400463 select IRQ_WORK
Mike Travisc903ff82009-01-15 12:28:29 -0800464 help
465 This option selects the RCU implementation that is
466 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700467 thousands of CPUs. It also scales down nicely to
468 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800469
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700470config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700471 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800472 depends on PREEMPT
James Hogan53614712013-07-25 15:34:25 +0100473 select IRQ_WORK
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700474 help
475 This option selects the RCU implementation that is
476 designed for very large SMP systems with hundreds or
477 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700478 is also required. It also scales down nicely to
479 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700480
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800481 Select this option if you are unsure.
482
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700483config TINY_RCU
484 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700485 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700486 help
487 This option selects the RCU implementation that is
488 designed for UP systems from which real-time response
489 is not required. This option greatly reduces the
490 memory footprint of RCU.
491
Mike Travisc903ff82009-01-15 12:28:29 -0800492endchoice
493
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700494config PREEMPT_RCU
Paul E. McKenney127781d2013-03-27 08:44:00 -0700495 def_bool TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700496 help
497 This option enables preemptible-RCU code that is common between
498 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
499
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700500config RCU_STALL_COMMON
501 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
502 help
503 This option enables RCU CPU stall code that is common between
504 the TINY and TREE variants of RCU. The purpose is to allow
505 the tiny variants to disable RCU CPU stall warnings, while
506 making these warnings mandatory for the tree variants.
507
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100508config CONTEXT_TRACKING
509 bool
510
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200511config RCU_USER_QS
512 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100513 depends on HAVE_CONTEXT_TRACKING && SMP
514 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200515 help
516 This option sets hooks on kernel / userspace boundaries and
517 puts RCU in extended quiescent state when the CPU runs in
518 userspace. It means that when a CPU runs in userspace, it is
519 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700520 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200521
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200522 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100523 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700524 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200525
526 If unsure say N
527
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100528config CONTEXT_TRACKING_FORCE
529 bool "Force context tracking"
530 depends on CONTEXT_TRACKING
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200531 default y if !NO_HZ_FULL
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200532 help
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200533 The major pre-requirement for full dynticks to work is to
534 support the context tracking subsystem. But there are also
535 other dependencies to provide in order to make the full
536 dynticks working.
537
538 This option stands for testing when an arch implements the
539 context tracking backend but doesn't yet fullfill all the
540 requirements to make the full dynticks feature working.
541 Without the full dynticks, there is no way to test the support
542 for context tracking and the subsystems that rely on it: RCU
543 userspace extended quiescent state and tickless cputime
544 accounting. This option copes with the absence of the full
545 dynticks subsystem by forcing the context tracking on all
546 CPUs in the system.
547
548 Say Y only if you're working on the developpement of an
549 architecture backend for the context tracking.
550
551 Say N otherwise, this option brings an overhead that you
552 don't want in production.
553
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200554
Mike Travisc903ff82009-01-15 12:28:29 -0800555config RCU_FANOUT
556 int "Tree-based hierarchical RCU fanout value"
557 range 2 64 if 64BIT
558 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700559 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800560 default 64 if 64BIT
561 default 32 if !64BIT
562 help
563 This option controls the fanout of hierarchical implementations
564 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700565 large numbers of CPUs. This value must be at least the fourth
566 root of NR_CPUS, which allows NR_CPUS to be insanely large.
567 The default value of RCU_FANOUT should be used for production
568 systems, but if you are stress-testing the RCU implementation
569 itself, small RCU_FANOUT values allow you to test large-system
570 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800571
572 Select a specific number if testing RCU itself.
573 Take the default if unsure.
574
Paul E. McKenney8932a632012-04-19 12:20:14 -0700575config RCU_FANOUT_LEAF
576 int "Tree-based hierarchical RCU leaf-level fanout value"
577 range 2 RCU_FANOUT if 64BIT
578 range 2 RCU_FANOUT if !64BIT
579 depends on TREE_RCU || TREE_PREEMPT_RCU
580 default 16
581 help
582 This option controls the leaf-level fanout of hierarchical
583 implementations of RCU, and allows trading off cache misses
584 against lock contention. Systems that synchronize their
585 scheduling-clock interrupts for energy-efficiency reasons will
586 want the default because the smaller leaf-level fanout keeps
587 lock contention levels acceptably low. Very large systems
588 (hundreds or thousands of CPUs) will instead want to set this
589 value to the maximum value possible in order to reduce the
590 number of cache misses incurred during RCU's grace-period
591 initialization. These systems tend to run CPU-bound, and thus
592 are not helped by synchronized interrupts, and thus tend to
593 skew them, which reduces lock contention enough that large
594 leaf-level fanouts work well.
595
596 Select a specific number if testing RCU itself.
597
598 Select the maximum permissible value for large systems.
599
600 Take the default if unsure.
601
Mike Travisc903ff82009-01-15 12:28:29 -0800602config RCU_FANOUT_EXACT
603 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700604 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800605 default n
606 help
607 This option forces use of the exact RCU_FANOUT value specified,
608 regardless of imbalances in the hierarchy. This is useful for
609 testing RCU itself, and might one day be useful on systems with
610 strong NUMA behavior.
611
612 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
613
614 Say N if unsure.
615
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800616config RCU_FAST_NO_HZ
617 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200618 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800619 default n
620 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800621 This option permits CPUs to enter dynticks-idle state even if
622 they have RCU callbacks queued, and prevents RCU from waking
623 these CPUs up more than roughly once every four jiffies (by
624 default, you can adjust this using the rcutree.rcu_idle_gp_delay
625 parameter), thus improving energy efficiency. On the other
626 hand, this option increases the duration of RCU grace periods,
627 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800628
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800629 Say Y if energy efficiency is critically important, and you
630 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800631
632 Say N if you are unsure.
633
Mike Travisc903ff82009-01-15 12:28:29 -0800634config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700635 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800636 select DEBUG_FS
637 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700638 This option provides tracing for the TREE_RCU and
639 TREE_PREEMPT_RCU implementations, permitting Makefile to
640 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800641
Paul E. McKenney24278d12010-09-27 17:25:23 -0700642config RCU_BOOST
643 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800644 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700645 default n
646 help
647 This option boosts the priority of preempted RCU readers that
648 block the current preemptible RCU grace period for too long.
649 This option also prevents heavy loads from blocking RCU
650 callback invocation for all flavors of RCU.
651
652 Say Y here if you are working with real-time apps or heavy loads
653 Say N here if you are unsure.
654
655config RCU_BOOST_PRIO
656 int "Real-time priority to boost RCU readers to"
657 range 1 99
658 depends on RCU_BOOST
659 default 1
660 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700661 This option specifies the real-time priority to which long-term
662 preempted RCU readers are to be boosted. If you are working
663 with a real-time application that has one or more CPU-bound
664 threads running at a real-time priority level, you should set
665 RCU_BOOST_PRIO to a priority higher then the highest-priority
666 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
667 of 1 is appropriate in the common case, which is real-time
668 applications that do not have any CPU-bound threads.
669
670 Some real-time applications might not have a single real-time
671 thread that saturates a given CPU, but instead might have
672 multiple real-time threads that, taken together, fully utilize
673 that CPU. In this case, you should set RCU_BOOST_PRIO to
674 a priority higher than the lowest-priority thread that is
675 conspiring to prevent the CPU from running any non-real-time
676 tasks. For example, if one thread at priority 10 and another
677 thread at priority 5 are between themselves fully consuming
678 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
679 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700680
681 Specify the real-time priority, or take the default if unsure.
682
683config RCU_BOOST_DELAY
684 int "Milliseconds to delay boosting after RCU grace-period start"
685 range 0 3000
686 depends on RCU_BOOST
687 default 500
688 help
689 This option specifies the time to wait after the beginning of
690 a given grace period before priority-boosting preempted RCU
691 readers blocking that grace period. Note that any RCU reader
692 blocking an expedited RCU grace period is boosted immediately.
693
694 Accept the default if unsure.
695
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700696config RCU_NOCB_CPU
Paul E. McKenney9a5739d2013-03-28 20:48:36 -0700697 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700698 depends on TREE_RCU || TREE_PREEMPT_RCU
699 default n
700 help
701 Use this option to reduce OS jitter for aggressive HPC or
702 real-time workloads. It can also be used to offload RCU
703 callback invocation to energy-efficient CPUs in battery-powered
704 asymmetric multiprocessors.
705
706 This option offloads callback invocation from the set of
707 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800708 For each such CPU, a kthread ("rcuox/N") will be created to
709 invoke callbacks, where the "N" is the CPU being offloaded,
710 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
711 "s" for RCU-sched. Nothing prevents this kthread from running
712 on the specified CPUs, but (1) the kthreads may be preempted
713 between each callback, and (2) affinity or cgroups can be used
714 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700715
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800716 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700717 Say N here if you are unsure.
718
Paul E. McKenney911af502013-02-11 10:23:27 -0800719choice
720 prompt "Build-forced no-CBs CPUs"
721 default RCU_NOCB_CPU_NONE
722 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700723 This option allows no-CBs CPUs (whose RCU callbacks are invoked
724 from kthreads rather than from softirq context) to be specified
725 at build time. Additional no-CBs CPUs may be specified by
726 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800727
728config RCU_NOCB_CPU_NONE
729 bool "No build_forced no-CBs CPUs"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200730 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800731 help
732 This option does not force any of the CPUs to be no-CBs CPUs.
733 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700734 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
735 kthreads whose names begin with "rcuo". All other CPUs will
736 invoke their own RCU callbacks in softirq context.
737
738 Select this option if you want to choose no-CBs CPUs at
739 boot time, for example, to allow testing of different no-CBs
740 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800741
742config RCU_NOCB_CPU_ZERO
743 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200744 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800745 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700746 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
747 callbacks are invoked by a per-CPU kthread whose name begins
748 with "rcuo". Additional CPUs may be designated as no-CBs
749 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
750 All other CPUs will invoke their own RCU callbacks in softirq
751 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800752
753 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700754 or energy-efficiency reasons, but the real reason it exists
755 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800756
757config RCU_NOCB_CPU_ALL
758 bool "All CPUs are build_forced no-CBs CPUs"
759 depends on RCU_NOCB_CPU
760 help
761 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700762 boot parameter will be ignored. All CPUs' RCU callbacks will
763 be executed in the context of per-CPU rcuo kthreads created for
764 this purpose. Assuming that the kthreads whose names start with
765 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
766 on the remaining CPUs, but might decrease memory locality during
767 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800768
769 Select this if all CPUs need to be no-CBs CPUs for real-time
770 or energy-efficiency reasons.
771
772endchoice
773
Mike Travisc903ff82009-01-15 12:28:29 -0800774endmenu # "RCU Subsystem"
775
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700777 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 ---help---
779 This option enables the complete Linux kernel ".config" file
780 contents to be saved in the kernel. It provides documentation
781 of which kernel options are used in a running kernel or in an
782 on-disk kernel. This information can be extracted from the kernel
783 image file with the script scripts/extract-ikconfig and used as
784 input to rebuild the current kernel or to build another kernel.
785 It can also be extracted from a running kernel by reading
786 /proc/config.gz if enabled (below).
787
788config IKCONFIG_PROC
789 bool "Enable access to .config through /proc/config.gz"
790 depends on IKCONFIG && PROC_FS
791 ---help---
792 This option enables access to the kernel configuration file
793 through /proc/config.gz.
794
Alistair John Strachan794543a2007-05-08 00:31:15 -0700795config LOG_BUF_SHIFT
796 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
797 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700798 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700799 help
800 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700801 Examples:
802 17 => 128 KB
803 16 => 64 KB
804 15 => 32 KB
805 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700806 13 => 8 KB
807 12 => 4 KB
808
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800809#
810# Architectures with an unreliable sched_clock() should select this:
811#
812config HAVE_UNSTABLE_SCHED_CLOCK
813 bool
814
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700815config GENERIC_SCHED_CLOCK
816 bool
817
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200818#
819# For architectures that want to enable the support for NUMA-affine scheduler
820# balancing logic:
821#
822config ARCH_SUPPORTS_NUMA_BALANCING
823 bool
824
825# For architectures that (ab)use NUMA to represent different memory regions
826# all cpu-local but of different latencies, such as SuperH.
827#
828config ARCH_WANT_NUMA_VARIABLE_LOCALITY
829 bool
830
831#
832# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
833config ARCH_WANTS_PROT_NUMA_PROT_NONE
834 bool
835
836config ARCH_USES_NUMA_PROT_NONE
837 bool
838 default y
839 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
840 depends on NUMA_BALANCING
841
Mel Gorman1a687c22012-11-22 11:16:36 +0000842config NUMA_BALANCING_DEFAULT_ENABLED
843 bool "Automatically enable NUMA aware memory/task placement"
844 default y
845 depends on NUMA_BALANCING
846 help
847 If set, autonumic NUMA balancing will be enabled if running on a NUMA
848 machine.
849
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200850config NUMA_BALANCING
851 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200852 depends on ARCH_SUPPORTS_NUMA_BALANCING
853 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
854 depends on SMP && NUMA && MIGRATION
855 help
856 This option adds support for automatic NUMA aware memory/task placement.
857 The mechanism is quite primitive and is based on migrating memory when
858 it is references to the node the task is running on.
859
860 This system will be inactive on UMA systems.
861
Li Zefan23964d22009-01-15 13:50:58 -0800862menuconfig CGROUPS
863 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800864 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700865 help
Li Zefan23964d22009-01-15 13:50:58 -0800866 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800867 use with process control subsystems such as Cpusets, CFS, memory
868 controls or device isolation.
869 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800870 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800871 - Documentation/cgroups/ (features for grouping, isolation
872 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700873
874 Say N if unsure.
875
Li Zefan23964d22009-01-15 13:50:58 -0800876if CGROUPS
877
Paul Menage006cb992007-10-18 23:39:43 -0700878config CGROUP_DEBUG
879 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700880 default n
Paul Menage006cb992007-10-18 23:39:43 -0700881 help
882 This option enables a simple cgroup subsystem that
883 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800884 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700885
Li Zefan23964d22009-01-15 13:50:58 -0800886 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700887
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700888config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800889 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800890 help
891 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700892 cgroup.
893
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700894config CGROUP_DEVICE
895 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700896 help
897 Provides a cgroup implementing whitelists for devices which
898 a process in the cgroup can mknod or open.
899
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900config CPUSETS
901 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700903 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 allow dynamically partitioning a system into sets of CPUs and
905 Memory Nodes and assigning tasks to run only within those sets.
906 This is primarily useful on large SMP or NUMA systems.
907
908 Say N if unsure.
909
Li Zefan23964d22009-01-15 13:50:58 -0800910config PROC_PID_CPUSET
911 bool "Include legacy /proc/<pid>/cpuset file"
912 depends on CPUSETS
913 default y
914
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100915config CGROUP_CPUACCT
916 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100917 help
918 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800919 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100920
Pavel Emelianove552b662008-02-07 00:13:49 -0800921config RESOURCE_COUNTERS
922 bool "Resource counters"
923 help
924 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800925 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800926
Andrew Mortonc255a452012-07-31 16:43:02 -0700927config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800928 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700929 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700930 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800931 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700932 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100933 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800934
935 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700936 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700937 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700938 usage tracking struct at boot. Total amount of this is printed out
939 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800940
941 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700942 sure you need the memory resource controller. Even when you enable
943 this, you can set "cgroup_disable=memory" at your boot option to
944 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800945 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800946
Balbir Singhcf475ad2008-04-29 01:00:16 -0700947 This config option also selects MM_OWNER config option, which
948 could in turn add some fork/exit overhead.
949
Andrew Mortonc255a452012-07-31 16:43:02 -0700950config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700951 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700952 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800953 help
954 Add swap management feature to memory resource controller. When you
955 enable this, you can limit mem+swap usage per cgroup. In other words,
956 when you disable this, memory resource controller has no cares to
957 usage of swap...a process can exhaust all of the swap. This extension
958 is useful when you want to avoid exhaustion swap but this itself
959 adds more overheads and consumes memory for remembering information.
960 Especially if you use 32bit system or small memory system, please
961 be careful about enabling this. When memory resource controller
962 is disabled by boot option, this will be automatically disabled and
963 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700964 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700965 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
966 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700967config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800968 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700969 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800970 default y
971 help
972 Memory Resource Controller Swap Extension comes with its price in
973 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700974 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -0700975 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -0800976 parameter should have this option unselected.
977 For those who want to have the feature enabled by default should
978 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700979 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700980config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700981 bool "Memory Resource Controller Kernel Memory accounting"
982 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800983 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000984 help
985 The Kernel Memory extension for Memory Resource Controller can limit
986 the amount of memory used by kernel objects in the system. Those are
987 fundamentally different from the entities handled by the standard
988 Memory Controller, which are page-based, and can be swapped. Users of
989 the kmem extension can use it to guarantee that no group of processes
990 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800991
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700992config CGROUP_HUGETLB
993 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700994 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700995 default n
996 help
997 Provides a cgroup Resource Controller for HugeTLB pages.
998 When you enable this, you can put a per cgroup limit on HugeTLB usage.
999 The limit is enforced during page fault. Since HugeTLB doesn't
1000 support page reclaim, enforcing the limit at page fault time implies
1001 that, the application will get SIGBUS signal if it tries to access
1002 HugeTLB pages beyond its limit. This requires the application to know
1003 beforehand how much HugeTLB pages it would require for its use. The
1004 control group is tracked in the third page lru pointer. This means
1005 that we cannot use the controller with huge page less than 3 pages.
1006
Stephane Eraniane5d13672011-02-14 11:20:01 +02001007config CGROUP_PERF
1008 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
1009 depends on PERF_EVENTS && CGROUPS
1010 help
1011 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +08001012 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001013 designated cpu.
1014
1015 Say N if unsure.
1016
Dhaval Giani7c941432010-01-20 13:26:18 +01001017menuconfig CGROUP_SCHED
1018 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001019 default n
1020 help
1021 This feature lets CPU scheduler recognize task groups and control CPU
1022 bandwidth allocation to such task groups. It uses cgroups to group
1023 tasks.
1024
1025if CGROUP_SCHED
1026config FAIR_GROUP_SCHED
1027 bool "Group scheduling for SCHED_OTHER"
1028 depends on CGROUP_SCHED
1029 default CGROUP_SCHED
1030
Paul Turnerab84d312011-07-21 09:43:28 -07001031config CFS_BANDWIDTH
1032 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001033 depends on FAIR_GROUP_SCHED
1034 default n
1035 help
1036 This option allows users to define CPU bandwidth rates (limits) for
1037 tasks running within the fair group scheduler. Groups with no limit
1038 set are considered to be unconstrained and will run with no
1039 restriction.
1040 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1041
Dhaval Giani7c941432010-01-20 13:26:18 +01001042config RT_GROUP_SCHED
1043 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001044 depends on CGROUP_SCHED
1045 default n
1046 help
1047 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001048 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001049 schedule realtime tasks for non-root users until you allocate
1050 realtime bandwidth for them.
1051 See Documentation/scheduler/sched-rt-group.txt for more information.
1052
1053endif #CGROUP_SCHED
1054
Vivek Goyalafc24d42010-04-26 19:27:56 +02001055config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001056 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001057 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001058 default n
1059 ---help---
1060 Generic block IO controller cgroup interface. This is the common
1061 cgroup interface which should be used by various IO controlling
1062 policies.
1063
1064 Currently, CFQ IO scheduler uses it to recognize task groups and
1065 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001066 to such task groups. It is also used by bio throttling logic in
1067 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001068
1069 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001070 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001071 enabling proportional weight division of disk bandwidth in CFQ, set
1072 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001073 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001074
1075 See Documentation/cgroups/blkio-controller.txt for more information.
1076
1077config DEBUG_BLK_CGROUP
1078 bool "Enable Block IO controller debugging"
1079 depends on BLK_CGROUP
1080 default n
1081 ---help---
1082 Enable some debugging help. Currently it exports additional stat
1083 files in a cgroup which can be useful for debugging.
1084
Li Zefan23964d22009-01-15 13:50:58 -08001085endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001086
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001087config CHECKPOINT_RESTORE
1088 bool "Checkpoint/restore support" if EXPERT
1089 default n
1090 help
1091 Enables additional kernel features in a sake of checkpoint/restore.
1092 In particular it adds auxiliary prctl codes to setup process text,
1093 data and heap segment sizes, and a few additional /proc filesystem
1094 entries.
1095
1096 If unsure, say N here.
1097
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001098menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001099 bool "Namespaces support" if EXPERT
1100 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001101 help
1102 Provides the way to make tasks work with different objects using
1103 the same id. For example same IPC id may refer to different objects
1104 or same user id or pid may refer to different tasks when used in
1105 different namespaces.
1106
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001107if NAMESPACES
1108
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001109config UTS_NS
1110 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001111 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001112 help
1113 In this namespace tasks see different info provided with the
1114 uname() system call
1115
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001116config IPC_NS
1117 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001118 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001119 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001120 help
1121 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001122 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001123
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001124config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001125 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001126 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001127
Eric W. Biederman5673a942011-11-17 10:23:55 -08001128 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001129 help
1130 This allows containers, i.e. vservers, to use user namespaces
1131 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001132
1133 When user namespaces are enabled in the kernel it is
1134 recommended that the MEMCG and MEMCG_KMEM options also be
1135 enabled and that user-space use the memory control groups to
1136 limit the amount of memory a memory unprivileged users can
1137 use.
1138
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001139 If unsure, say N.
1140
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001141config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001142 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001143 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001144 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001145 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001146 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001147 pid namespaces. This is a building block of containers.
1148
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001149config NET_NS
1150 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001151 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001152 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001153 help
1154 Allow user space to create what appear to be multiple instances
1155 of the network stack.
1156
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001157endif # NAMESPACES
1158
Eric W. Biederman5673a942011-11-17 10:23:55 -08001159config UIDGID_STRICT_TYPE_CHECKS
1160 bool "Require conversions between uid/gids and their internal representation"
1161 default n
1162 help
1163 While the nececessary conversions are being added to all subsystems this option allows
1164 the code to continue to build for unconverted subsystems.
1165
1166 Say Y here if you want the strict type checking enabled
1167
Mike Galbraith5091faa2010-11-30 14:18:03 +01001168config SCHED_AUTOGROUP
1169 bool "Automatic process group scheduling"
1170 select EVENTFD
1171 select CGROUPS
1172 select CGROUP_SCHED
1173 select FAIR_GROUP_SCHED
1174 help
1175 This option optimizes the scheduler for common desktop workloads by
1176 automatically creating and populating task groups. This separation
1177 of workloads isolates aggressive CPU burners (like build jobs) from
1178 desktop applications. Task group autogeneration is currently based
1179 upon task session.
1180
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001181config MM_OWNER
1182 bool
1183
1184config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001185 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001186 depends on SYSFS
1187 default n
1188 help
1189 This option adds code that switches the layout of the "block" class
1190 devices, to not show up in /sys/class/block/, but only in
1191 /sys/block/.
1192
1193 This switch is only active when the sysfs.deprecated=1 boot option is
1194 passed or the SYSFS_DEPRECATED_V2 option is set.
1195
1196 This option allows new kernels to run on old distributions and tools,
1197 which might get confused by /sys/class/block/. Since 2007/2008 all
1198 major distributions and tools handle this just fine.
1199
1200 Recent distributions and userspace tools after 2009/2010 depend on
1201 the existence of /sys/class/block/, and will not work with this
1202 option enabled.
1203
1204 Only if you are using a new kernel on an old distribution, you might
1205 need to say Y here.
1206
1207config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001208 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001209 default n
1210 depends on SYSFS
1211 depends on SYSFS_DEPRECATED
1212 help
1213 Enable deprecated sysfs by default.
1214
1215 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1216 option.
1217
1218 Only if you are using a new kernel on an old distribution, you might
1219 need to say Y here. Even then, odds are you would not need it
1220 enabled, you can always pass the boot option if absolutely necessary.
1221
1222config RELAY
1223 bool "Kernel->user space relay support (formerly relayfs)"
1224 help
1225 This option enables support for relay interface support in
1226 certain file systems (such as debugfs).
1227 It is designed to provide an efficient mechanism for tools and
1228 facilities to relay large amounts of data from kernel space to
1229 user space.
1230
1231 If unsure, say N.
1232
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001233config BLK_DEV_INITRD
1234 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1235 depends on BROKEN || !FRV
1236 help
1237 The initial RAM filesystem is a ramfs which is loaded by the
1238 boot loader (loadlin or lilo) and that is mounted as root
1239 before the normal boot procedure. It is typically used to
1240 load modules needed to mount the "real" root file system,
1241 etc. See <file:Documentation/initrd.txt> for details.
1242
1243 If RAM disk support (BLK_DEV_RAM) is also included, this
1244 also enables initial RAM disk (initrd) support and adds
1245 15 Kbytes (more on some other architectures) to the kernel size.
1246
1247 If unsure say Y.
1248
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001249if BLK_DEV_INITRD
1250
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001251source "usr/Kconfig"
1252
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001253endif
1254
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001255config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001256 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001257 help
1258 Enabling this option will pass "-Os" instead of "-O2" to gcc
1259 resulting in a smaller kernel.
1260
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001261 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001262
Randy Dunlap08470622006-09-30 23:28:13 -07001263config SYSCTL
1264 bool
1265
Randy Dunlapb943c462009-03-10 12:55:46 -07001266config ANON_INODES
1267 bool
1268
Mike Frysinger657a5202013-04-30 15:28:45 -07001269config HAVE_UID16
1270 bool
1271
1272config SYSCTL_EXCEPTION_TRACE
1273 bool
1274 help
1275 Enable support for /proc/sys/debug/exception-trace.
1276
1277config SYSCTL_ARCH_UNALIGN_NO_WARN
1278 bool
1279 help
1280 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1281 Allows arch to define/use @no_unaligned_warning to possibly warn
1282 about unaligned access emulation going on under the hood.
1283
1284config SYSCTL_ARCH_UNALIGN_ALLOW
1285 bool
1286 help
1287 Enable support for /proc/sys/kernel/unaligned-trap
1288 Allows arches to define/use @unaligned_enabled to runtime toggle
1289 the unaligned access emulation.
1290 see arch/parisc/kernel/unaligned.c for reference
1291
Mike Frysinger657a5202013-04-30 15:28:45 -07001292config HAVE_PCSPKR_PLATFORM
1293 bool
1294
David Rientjes6a108a12011-01-20 14:44:16 -08001295menuconfig EXPERT
1296 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001297 # Unhide debug options, to make the on-by-default options visible
1298 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 help
1300 This option allows certain base kernel options and settings
1301 to be disabled or tweaked. This is for specialized
1302 environments which can tolerate a "non-standard" kernel.
1303 Only use this if you really know what you are doing.
1304
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001305config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001306 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001307 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001308 default y
1309 help
1310 This enables the legacy 16-bit UID syscall wrappers.
1311
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001312config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001313 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001314 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001315 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001316 select SYSCTL
1317 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001318 sys_sysctl uses binary paths that have been found challenging
1319 to properly maintain and use. The interface in /proc/sys
1320 using paths with ascii names is now the primary path to this
1321 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001322
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001323 Almost nothing using the binary sysctl interface so if you are
1324 trying to save some space it is probably safe to disable this,
1325 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001326
WANG Congc736de62011-11-02 13:39:25 -07001327 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001328
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001330 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 default y
1332 help
1333 Say Y here to let the kernel print out symbolic crash information and
1334 symbolic stack backtraces. This increases the size of the kernel
1335 somewhat, as all symbols have to be loaded into the kernel image.
1336
1337config KALLSYMS_ALL
1338 bool "Include all symbols in kallsyms"
1339 depends on DEBUG_KERNEL && KALLSYMS
1340 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001341 Normally kallsyms only contains the symbols of functions for nicer
1342 OOPS messages and backtraces (i.e., symbols from the text and inittext
1343 sections). This is sufficient for most cases. And only in very rare
1344 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1345 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001347 This option makes sure that all symbols are loaded into the kernel
1348 image (i.e., symbols from all sections) in cost of increased kernel
1349 size (depending on the kernel configuration, it may be 300KiB or
1350 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001352 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001353
1354config PRINTK
1355 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001356 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001357 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001358 help
1359 This option enables normal printk support. Removing it
1360 eliminates most of the message strings from the kernel image
1361 and makes the kernel more or less silent. As this makes it
1362 very difficult to diagnose system problems, saying N here is
1363 strongly discouraged.
1364
Matt Mackallc8538a72005-05-01 08:59:01 -07001365config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001366 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001367 default y
1368 help
1369 Disabling this option eliminates support for BUG and WARN, reducing
1370 the size of your kernel image and potentially quietly ignoring
1371 numerous fatal conditions. You should only consider disabling this
1372 option for embedded systems with no facilities for reporting errors.
1373 Just say Y.
1374
Matt Mackall708e9a72006-01-08 01:05:25 -08001375config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001376 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001377 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001378 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001379 help
1380 Enable support for generating core dumps. Disabling saves about 4k.
1381
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001382
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001383config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001384 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001385 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001386 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001387 default y
1388 help
1389 This option allows to disable the internal PC-Speaker
1390 support, saving some memory.
1391
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392config BASE_FULL
1393 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001394 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 help
1396 Disabling this option reduces the size of miscellaneous core
1397 kernel data structures. This saves memory on small machines,
1398 but may reduce performance.
1399
1400config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001401 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001403 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 help
1405 Disabling this option will cause the kernel to be built without
1406 support for "fast userspace mutexes". The resulting kernel may not
1407 run glibc-based applications correctly.
1408
1409config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001410 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001412 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 help
1414 Disabling this option will cause the kernel to be built without
1415 support for epoll family of system calls.
1416
Davide Libenzifba2afa2007-05-10 22:23:13 -07001417config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001418 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001419 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001420 default y
1421 help
1422 Enable the signalfd() system call that allows to receive signals
1423 on a file descriptor.
1424
1425 If unsure, say Y.
1426
Davide Libenzib215e282007-05-10 22:23:16 -07001427config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001428 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001429 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001430 default y
1431 help
1432 Enable the timerfd() system call that allows to receive timer
1433 events on a file descriptor.
1434
1435 If unsure, say Y.
1436
Davide Libenzie1ad7462007-05-10 22:23:19 -07001437config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001438 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001439 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001440 default y
1441 help
1442 Enable the eventfd() system call that allows to receive both
1443 kernel notification (ie. KAIO) or userspace notifications.
1444
1445 If unsure, say Y.
1446
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001448 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 default y
1450 depends on MMU
1451 help
1452 The shmem is an internal filesystem used to manage shared memory.
1453 It is backed by swap and manages resource limits. It is also exported
1454 to userspace as tmpfs if TMPFS is enabled. Disabling this
1455 option replaces shmem and tmpfs with the much simpler ramfs code,
1456 which may be appropriate on small systems without swap.
1457
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001458config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001459 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001460 default y
1461 help
1462 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001463 by some high performance threaded applications. Disabling
1464 this option saves about 7k.
1465
1466config PCI_QUIRKS
1467 default y
1468 bool "Enable PCI quirk workarounds" if EXPERT
1469 depends on PCI
1470 help
1471 This enables workarounds for various PCI chipset
1472 bugs/quirks. Disable this only if your target machine is
1473 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001474
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001475config EMBEDDED
1476 bool "Embedded system"
1477 select EXPERT
1478 help
1479 This option should be enabled if compiling the kernel for
1480 an embedded system so certain expert options are available
1481 for configuration.
1482
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001483config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001484 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001485 help
1486 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001487
Peter Zijlstra906010b2009-09-21 16:08:49 +02001488config PERF_USE_VMALLOC
1489 bool
1490 help
1491 See tools/perf/design.txt for details
1492
Ingo Molnar57c0c152009-09-21 12:20:38 +02001493menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001494
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001495config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001496 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001497 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001498 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001499 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001500 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001501 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001502 Enable kernel support for various performance events provided
1503 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001504
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001505 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001506 use of generic tracepoints.
1507
1508 Most modern CPUs support performance events via performance
1509 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001510 types of hw events: such as instructions executed, cachemisses
1511 suffered, or branches mis-predicted - without slowing down the
1512 kernel or applications. These registers can also trigger interrupts
1513 when a threshold number of events have passed - and can thus be
1514 used to profile the code that runs on that CPU.
1515
Ingo Molnar57c0c152009-09-21 12:20:38 +02001516 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001517 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001518 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001519 provides per task and per CPU counters, and it provides event
1520 capabilities on top of those.
1521
1522 Say Y if unsure.
1523
Peter Zijlstra906010b2009-09-21 16:08:49 +02001524config DEBUG_PERF_USE_VMALLOC
1525 default n
1526 bool "Debug: use vmalloc to back perf mmap() buffers"
1527 depends on PERF_EVENTS && DEBUG_KERNEL
1528 select PERF_USE_VMALLOC
1529 help
1530 Use vmalloc memory to back perf mmap() buffers.
1531
1532 Mostly useful for debugging the vmalloc code on platforms
1533 that don't require it.
1534
1535 Say N if unsure.
1536
Thomas Gleixner0793a612008-12-04 20:12:29 +01001537endmenu
1538
Christoph Lameterf8891e52006-06-30 01:55:45 -07001539config VM_EVENT_COUNTERS
1540 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001541 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001542 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001543 VM event counters are needed for event counts to be shown.
1544 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001545 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001546 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001547
Christoph Lameter41ecc552007-05-09 02:32:44 -07001548config SLUB_DEBUG
1549 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001550 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001551 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001552 help
1553 SLUB has extensive debug support features. Disabling these can
1554 result in significant savings in code size. This also disables
1555 SLUB sysfs support. /sys/slab will not exist and there will be
1556 no support for cache validation etc.
1557
Randy Dunlapb943c462009-03-10 12:55:46 -07001558config COMPAT_BRK
1559 bool "Disable heap randomization"
1560 default y
1561 help
1562 Randomizing heap placement makes heap exploits harder, but it
1563 also breaks ancient binaries (including anything libc5 based).
1564 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001565 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001566 /proc/sys/kernel/randomize_va_space to 2.
1567
1568 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1569
Christoph Lameter81819f02007-05-06 14:49:36 -07001570choice
1571 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001572 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001573 help
1574 This option allows to select a slab allocator.
1575
1576config SLAB
1577 bool "SLAB"
1578 help
1579 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001580 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001581 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001582
1583config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001584 bool "SLUB (Unqueued Allocator)"
1585 help
1586 SLUB is a slab allocator that minimizes cache line usage
1587 instead of managing queues of cached objects (SLAB approach).
1588 Per cpu caching is realized using slabs of objects instead
1589 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001590 and has enhanced diagnostics. SLUB is the default choice for
1591 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001592
1593config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001594 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001595 bool "SLOB (Simple Allocator)"
1596 help
Matt Mackall37291452008-02-04 22:29:38 -08001597 SLOB replaces the stock allocator with a drastically simpler
1598 allocator. SLOB is generally more space efficient but
1599 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001600
1601endchoice
1602
Joonsoo Kim345c9052013-06-19 14:05:52 +09001603config SLUB_CPU_PARTIAL
1604 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001605 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001606 bool "SLUB per cpu partial cache"
1607 help
1608 Per cpu partial caches accellerate objects allocation and freeing
1609 that is local to a processor at the price of more indeterminism
1610 in the latency of the free. On overflow these caches will be cleared
1611 which requires the taking of locks that may cause latency spikes.
1612 Typically one would choose no for a realtime system.
1613
Jie Zhangea637632009-12-14 18:00:02 -08001614config MMAP_ALLOW_UNINITIALIZED
1615 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001616 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001617 default n
1618 help
1619 Normally, and according to the Linux spec, anonymous memory obtained
1620 from mmap() has it's contents cleared before it is passed to
1621 userspace. Enabling this config option allows you to request that
1622 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1623 providing a huge performance boost. If this option is not enabled,
1624 then the flag will be ignored.
1625
1626 This is taken advantage of by uClibc's malloc(), and also by
1627 ELF-FDPIC binfmt's brk and stack allocator.
1628
1629 Because of the obvious security issues, this option should only be
1630 enabled on embedded devices where you control what is run in
1631 userspace. Since that isn't generally a problem on no-MMU systems,
1632 it is normally safe to say Y here.
1633
1634 See Documentation/nommu-mmap.txt for more information.
1635
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001636config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001637 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001638 help
1639 Say Y here to enable the extended profiling support mechanisms used
1640 by profilers such as OProfile.
1641
Ingo Molnar5f87f112008-07-23 14:15:22 +02001642#
1643# Place an empty function call at each tracepoint site. Can be
1644# dynamically changed for a probe function.
1645#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001646config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001647 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001648
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001649source "arch/Kconfig"
1650
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651endmenu # General setup
1652
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001653config HAVE_GENERIC_DMA_COHERENT
1654 bool
1655 default n
1656
Linus Torvalds158a9622008-01-02 13:04:48 -08001657config SLABINFO
1658 bool
1659 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001660 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001661 default y
1662
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001663config RT_MUTEXES
1664 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001665
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666config BASE_SMALL
1667 int
1668 default 0 if BASE_FULL
1669 default 1 if !BASE_FULL
1670
Jan Engelhardt66da5732007-07-15 23:39:29 -07001671menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001673 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674 help
1675 Kernel modules are small pieces of compiled code which can
1676 be inserted in the running kernel, rather than being
1677 permanently built into the kernel. You use the "modprobe"
1678 tool to add (and sometimes remove) them. If you say Y here,
1679 many parts of the kernel can be built as modules (by
1680 answering M instead of Y where indicated): this is most
1681 useful for infrequently used options which are not required
1682 for booting. For more information, see the man pages for
1683 modprobe, lsmod, modinfo, insmod and rmmod.
1684
1685 If you say Y here, you will need to run "make
1686 modules_install" to put the modules under /lib/modules/
1687 where modprobe can find them (you may need to be root to do
1688 this).
1689
1690 If unsure, say Y.
1691
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001692if MODULES
1693
Linus Torvalds826e4502008-05-04 17:04:16 -07001694config MODULE_FORCE_LOAD
1695 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001696 default n
1697 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001698 Allow loading of modules without version information (ie. modprobe
1699 --force). Forced module loading sets the 'F' (forced) taint flag and
1700 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001701
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702config MODULE_UNLOAD
1703 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 help
1705 Without this option you will not be able to unload any
1706 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001707 anyway), which makes your kernel smaller, faster
1708 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709
1710config MODULE_FORCE_UNLOAD
1711 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001712 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 help
1714 This option allows you to force a module to unload, even if the
1715 kernel believes it is unsafe: the kernel will remove the module
1716 without waiting for anyone to stop using it (using the -f option to
1717 rmmod). This is mainly for kernel developers and desperate users.
1718 If unsure, say N.
1719
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001721 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001722 help
1723 Usually, you have to use modules compiled with your kernel.
1724 Saying Y here makes it sometimes possible to use modules
1725 compiled for different kernels, by adding enough information
1726 to the modules to (hopefully) spot any changes which would
1727 make them incompatible with the kernel you are running. If
1728 unsure, say N.
1729
1730config MODULE_SRCVERSION_ALL
1731 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732 help
1733 Modules which contain a MODULE_VERSION get an extra "srcversion"
1734 field inserted into their modinfo section, which contains a
1735 sum of the source files which made it. This helps maintainers
1736 see exactly which source was used to build a module (since
1737 others sometimes change the module source without updating
1738 the version). With this option, such a "srcversion" field
1739 will be created for all modules. If unsure, say N.
1740
Rusty Russell106a4ee2012-09-26 10:09:40 +01001741config MODULE_SIG
1742 bool "Module signature verification"
1743 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001744 select KEYS
1745 select CRYPTO
1746 select ASYMMETRIC_KEY_TYPE
1747 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1748 select PUBLIC_KEY_ALGO_RSA
1749 select ASN1
1750 select OID_REGISTRY
1751 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001752 help
1753 Check modules for valid signatures upon load: the signature
1754 is simply appended to the module. For more information see
1755 Documentation/module-signing.txt.
1756
David Howellsea0b6dc2012-09-26 10:09:50 +01001757 !!!WARNING!!! If you enable this option, you MUST make sure that the
1758 module DOES NOT get stripped after being signed. This includes the
1759 debuginfo strip done by some packagers (such as rpmbuild) and
1760 inclusion into an initramfs that wants the module size reduced.
1761
Rusty Russell106a4ee2012-09-26 10:09:40 +01001762config MODULE_SIG_FORCE
1763 bool "Require modules to be validly signed"
1764 depends on MODULE_SIG
1765 help
1766 Reject unsigned modules or signed modules for which we don't have a
1767 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001768
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301769config MODULE_SIG_ALL
1770 bool "Automatically sign all modules"
1771 default y
1772 depends on MODULE_SIG
1773 help
1774 Sign all modules during make modules_install. Without this option,
1775 modules must be signed manually, using the scripts/sign-file tool.
1776
1777comment "Do not forget to sign required modules with scripts/sign-file"
1778 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1779
David Howellsea0b6dc2012-09-26 10:09:50 +01001780choice
1781 prompt "Which hash algorithm should modules be signed with?"
1782 depends on MODULE_SIG
1783 help
1784 This determines which sort of hashing algorithm will be used during
1785 signature generation. This algorithm _must_ be built into the kernel
1786 directly so that signature verification can take place. It is not
1787 possible to load a signed module containing the algorithm to check
1788 the signature on that module.
1789
1790config MODULE_SIG_SHA1
1791 bool "Sign modules with SHA-1"
1792 select CRYPTO_SHA1
1793
1794config MODULE_SIG_SHA224
1795 bool "Sign modules with SHA-224"
1796 select CRYPTO_SHA256
1797
1798config MODULE_SIG_SHA256
1799 bool "Sign modules with SHA-256"
1800 select CRYPTO_SHA256
1801
1802config MODULE_SIG_SHA384
1803 bool "Sign modules with SHA-384"
1804 select CRYPTO_SHA512
1805
1806config MODULE_SIG_SHA512
1807 bool "Sign modules with SHA-512"
1808 select CRYPTO_SHA512
1809
1810endchoice
1811
Michal Marek22753672013-01-25 13:41:00 +10301812config MODULE_SIG_HASH
1813 string
1814 depends on MODULE_SIG
1815 default "sha1" if MODULE_SIG_SHA1
1816 default "sha224" if MODULE_SIG_SHA224
1817 default "sha256" if MODULE_SIG_SHA256
1818 default "sha384" if MODULE_SIG_SHA384
1819 default "sha512" if MODULE_SIG_SHA512
1820
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001821endif # MODULES
1822
Rusty Russell98a79d62008-12-13 21:19:41 +10301823config INIT_ALL_POSSIBLE
1824 bool
1825 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301826 Back when each arch used to define their own cpu_online_mask and
1827 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301828 with all 1s, and others with all 0s. When they were centralised,
1829 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001830 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301831
Linus Torvalds1da177e2005-04-16 15:20:36 -07001832config STOP_MACHINE
1833 bool
1834 default y
1835 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1836 help
1837 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001838
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001839source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001840
1841config PREEMPT_NOTIFIERS
1842 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001843
Steffen Klassert16295be2010-01-06 19:47:10 +11001844config PADATA
1845 depends on SMP
1846 bool
1847
Andi Kleen754b7b62012-10-04 17:11:27 -07001848# Can be selected by architectures with broken toolchains
1849# that get confused by correct const<->read_only section
1850# mappings
1851config BROKEN_RODATA
1852 bool
1853
David Howells4520c6a2012-09-21 23:31:13 +01001854config ASN1
1855 tristate
1856 help
1857 Build a simple ASN.1 grammar compiler that produces a bytecode output
1858 that can be interpreted by the ASN.1 stream decoder and used to
1859 inform it as to what tags are to be expected in a stream and what
1860 functions to call on what tags.
1861
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001862source "kernel/Kconfig.locks"