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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
H. Peter Anvin2d3c6272013-11-14 21:43:47 -0800121 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"
Kevin Hilmanff3fb252013-09-16 15:28:19 -0700357 depends on HAVE_CONTEXT_TRACKING
Kevin Hilman554b0002013-09-16 15:28:21 -0700358 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200359 select VIRT_CPU_ACCOUNTING
360 select CONTEXT_TRACKING
361 help
362 Select this option to enable task and CPU time accounting on full
363 dynticks systems. This accounting is implemented by watching every
364 kernel-user boundaries using the context tracking subsystem.
365 The accounting is thus performed at the expense of some significant
366 overhead.
367
368 For now this is only useful if you are working on the full
369 dynticks subsystem development.
370
371 If unsure, say N.
372
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200373config IRQ_TIME_ACCOUNTING
374 bool "Fine granularity task level IRQ time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200375 depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200376 help
377 Select this option to enable fine granularity task irq time
378 accounting. This is done by reading a timestamp on each
379 transitions between softirq and hardirq state, so there can be a
380 small performance impact.
381
382 If in doubt, say N here.
383
384endchoice
385
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200386config BSD_PROCESS_ACCT
387 bool "BSD Process Accounting"
388 help
389 If you say Y here, a user level program will be able to instruct the
390 kernel (via a special system call) to write process accounting
391 information to a file: whenever a process exits, information about
392 that process will be appended to the file by the kernel. The
393 information includes things such as creation time, owning user,
394 command name, memory usage, controlling terminal etc. (the complete
395 list is in the struct acct in <file:include/linux/acct.h>). It is
396 up to the user level program to do useful things with this
397 information. This is generally a good idea, so say Y.
398
399config BSD_PROCESS_ACCT_V3
400 bool "BSD Process Accounting version 3 file format"
401 depends on BSD_PROCESS_ACCT
402 default n
403 help
404 If you say Y here, the process accounting information is written
405 in a new file format that also logs the process IDs of each
406 process and it's parent. Note that this file format is incompatible
407 with previous v0/v1/v2 file formats, so you will need updated tools
408 for processing it. A preliminary version of these tools is available
409 at <http://www.gnu.org/software/acct/>.
410
411config TASKSTATS
Kees Cook19c92392012-10-02 11:19:29 -0700412 bool "Export task/process statistics through netlink"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200413 depends on NET
414 default n
415 help
416 Export selected statistics for tasks/processes through the
417 generic netlink interface. Unlike BSD process accounting, the
418 statistics are available during the lifetime of tasks/processes as
419 responses to commands. Like BSD accounting, they are sent to user
420 space on task exit.
421
422 Say N if unsure.
423
424config TASK_DELAY_ACCT
Kees Cook19c92392012-10-02 11:19:29 -0700425 bool "Enable per-task delay accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200426 depends on TASKSTATS
427 help
428 Collect information on time spent by a task waiting for system
429 resources like cpu, synchronous block I/O completion and swapping
430 in pages. Such statistics can help in setting a task's priorities
431 relative to other tasks for cpu, io, rss limits etc.
432
433 Say N if unsure.
434
435config TASK_XACCT
Kees Cook19c92392012-10-02 11:19:29 -0700436 bool "Enable extended accounting over taskstats"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200437 depends on TASKSTATS
438 help
439 Collect extended task accounting data and send the data
440 to userland for processing over the taskstats interface.
441
442 Say N if unsure.
443
444config TASK_IO_ACCOUNTING
Kees Cook19c92392012-10-02 11:19:29 -0700445 bool "Enable per-task storage I/O accounting"
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200446 depends on TASK_XACCT
447 help
448 Collect information on the number of bytes of storage I/O which this
449 task has caused.
450
451 Say N if unsure.
452
453endmenu # "CPU/Task time and stats accounting"
454
Mike Travisc903ff82009-01-15 12:28:29 -0800455menu "RCU Subsystem"
456
457choice
458 prompt "RCU Implementation"
Paul E. McKenney31c9a242009-04-02 21:06:25 -0700459 default TREE_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800460
Mike Travisc903ff82009-01-15 12:28:29 -0800461config TREE_RCU
462 bool "Tree-based hierarchical RCU"
Paul E. McKenney687d7a92010-07-21 06:52:40 -0700463 depends on !PREEMPT && SMP
Steven Rostedt016a8d52013-05-28 17:32:53 -0400464 select IRQ_WORK
Mike Travisc903ff82009-01-15 12:28:29 -0800465 help
466 This option selects the RCU implementation that is
467 designed for very large SMP system with hundreds or
Paul E. McKenneyc17ef452009-06-23 17:12:47 -0700468 thousands of CPUs. It also scales down nicely to
469 smaller systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800470
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700471config TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700472 bool "Preemptible tree-based hierarchical RCU"
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800473 depends on PREEMPT
James Hogan53614712013-07-25 15:34:25 +0100474 select IRQ_WORK
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700475 help
476 This option selects the RCU implementation that is
477 designed for very large SMP systems with hundreds or
478 thousands of CPUs, but for which real-time response
Paul E. McKenneybbe3eae2009-09-13 09:15:08 -0700479 is also required. It also scales down nicely to
480 smaller systems.
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700481
Paul E. McKenney9fc52d82013-01-08 15:48:33 -0800482 Select this option if you are unsure.
483
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700484config TINY_RCU
485 bool "UP-only small-memory-footprint RCU"
Paul E. McKenney8008e122011-06-08 16:31:33 -0700486 depends on !PREEMPT && !SMP
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700487 help
488 This option selects the RCU implementation that is
489 designed for UP systems from which real-time response
490 is not required. This option greatly reduces the
491 memory footprint of RCU.
492
Mike Travisc903ff82009-01-15 12:28:29 -0800493endchoice
494
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700495config PREEMPT_RCU
Paul E. McKenney127781d2013-03-27 08:44:00 -0700496 def_bool TREE_PREEMPT_RCU
Paul E. McKenneya57eb942010-06-29 16:49:16 -0700497 help
498 This option enables preemptible-RCU code that is common between
499 the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
500
Paul E. McKenney6bfc09e2012-10-19 12:49:17 -0700501config RCU_STALL_COMMON
502 def_bool ( TREE_RCU || TREE_PREEMPT_RCU || RCU_TRACE )
503 help
504 This option enables RCU CPU stall code that is common between
505 the TINY and TREE variants of RCU. The purpose is to allow
506 the tiny variants to disable RCU CPU stall warnings, while
507 making these warnings mandatory for the tree variants.
508
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100509config CONTEXT_TRACKING
510 bool
511
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200512config RCU_USER_QS
513 bool "Consider userspace as in RCU extended quiescent state"
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100514 depends on HAVE_CONTEXT_TRACKING && SMP
515 select CONTEXT_TRACKING
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200516 help
517 This option sets hooks on kernel / userspace boundaries and
518 puts RCU in extended quiescent state when the CPU runs in
519 userspace. It means that when a CPU runs in userspace, it is
520 excluded from the global RCU state machine and thus doesn't
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700521 try to keep the timer tick on for RCU.
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200522
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200523 Unless you want to hack and help the development of the full
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100524 dynticks mode, you shouldn't enable this option. It also
Paul Gortmakeraf71bef2012-10-24 11:07:09 -0700525 adds unnecessary overhead.
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200526
527 If unsure say N
528
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100529config CONTEXT_TRACKING_FORCE
530 bool "Force context tracking"
531 depends on CONTEXT_TRACKING
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200532 default y if !NO_HZ_FULL
Frederic Weisbecker1fd2b442012-07-11 20:26:40 +0200533 help
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200534 The major pre-requirement for full dynticks to work is to
535 support the context tracking subsystem. But there are also
536 other dependencies to provide in order to make the full
537 dynticks working.
538
539 This option stands for testing when an arch implements the
540 context tracking backend but doesn't yet fullfill all the
541 requirements to make the full dynticks feature working.
542 Without the full dynticks, there is no way to test the support
543 for context tracking and the subsystems that rely on it: RCU
544 userspace extended quiescent state and tickless cputime
545 accounting. This option copes with the absence of the full
546 dynticks subsystem by forcing the context tracking on all
547 CPUs in the system.
548
549 Say Y only if you're working on the developpement of an
550 architecture backend for the context tracking.
551
552 Say N otherwise, this option brings an overhead that you
553 don't want in production.
554
Frederic Weisbeckerd6771242012-10-11 01:48:28 +0200555
Mike Travisc903ff82009-01-15 12:28:29 -0800556config RCU_FANOUT
557 int "Tree-based hierarchical RCU fanout value"
558 range 2 64 if 64BIT
559 range 2 32 if !64BIT
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700560 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800561 default 64 if 64BIT
562 default 32 if !64BIT
563 help
564 This option controls the fanout of hierarchical implementations
565 of RCU, allowing RCU to work efficiently on machines with
Paul E. McKenney4d87ffa2010-08-04 17:31:12 -0700566 large numbers of CPUs. This value must be at least the fourth
567 root of NR_CPUS, which allows NR_CPUS to be insanely large.
568 The default value of RCU_FANOUT should be used for production
569 systems, but if you are stress-testing the RCU implementation
570 itself, small RCU_FANOUT values allow you to test large-system
571 code paths on small(er) systems.
Mike Travisc903ff82009-01-15 12:28:29 -0800572
573 Select a specific number if testing RCU itself.
574 Take the default if unsure.
575
Paul E. McKenney8932a632012-04-19 12:20:14 -0700576config RCU_FANOUT_LEAF
577 int "Tree-based hierarchical RCU leaf-level fanout value"
578 range 2 RCU_FANOUT if 64BIT
579 range 2 RCU_FANOUT if !64BIT
580 depends on TREE_RCU || TREE_PREEMPT_RCU
581 default 16
582 help
583 This option controls the leaf-level fanout of hierarchical
584 implementations of RCU, and allows trading off cache misses
585 against lock contention. Systems that synchronize their
586 scheduling-clock interrupts for energy-efficiency reasons will
587 want the default because the smaller leaf-level fanout keeps
588 lock contention levels acceptably low. Very large systems
589 (hundreds or thousands of CPUs) will instead want to set this
590 value to the maximum value possible in order to reduce the
591 number of cache misses incurred during RCU's grace-period
592 initialization. These systems tend to run CPU-bound, and thus
593 are not helped by synchronized interrupts, and thus tend to
594 skew them, which reduces lock contention enough that large
595 leaf-level fanouts work well.
596
597 Select a specific number if testing RCU itself.
598
599 Select the maximum permissible value for large systems.
600
601 Take the default if unsure.
602
Mike Travisc903ff82009-01-15 12:28:29 -0800603config RCU_FANOUT_EXACT
604 bool "Disable tree-based hierarchical RCU auto-balancing"
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700605 depends on TREE_RCU || TREE_PREEMPT_RCU
Mike Travisc903ff82009-01-15 12:28:29 -0800606 default n
607 help
608 This option forces use of the exact RCU_FANOUT value specified,
609 regardless of imbalances in the hierarchy. This is useful for
610 testing RCU itself, and might one day be useful on systems with
611 strong NUMA behavior.
612
613 Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
614
615 Say N if unsure.
616
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800617config RCU_FAST_NO_HZ
618 bool "Accelerate last non-dyntick-idle CPU's grace periods"
Frederic Weisbecker3451d022011-08-10 23:21:01 +0200619 depends on NO_HZ_COMMON && SMP
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800620 default n
621 help
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800622 This option permits CPUs to enter dynticks-idle state even if
623 they have RCU callbacks queued, and prevents RCU from waking
624 these CPUs up more than roughly once every four jiffies (by
625 default, you can adjust this using the rcutree.rcu_idle_gp_delay
626 parameter), thus improving energy efficiency. On the other
627 hand, this option increases the duration of RCU grace periods,
628 for example, slowing down synchronize_rcu().
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800629
Paul E. McKenneyc0f4dfd2012-12-28 11:30:36 -0800630 Say Y if energy efficiency is critically important, and you
631 don't care about increased grace-period durations.
Paul E. McKenney8bd93a22010-02-22 17:04:59 -0800632
633 Say N if you are unsure.
634
Mike Travisc903ff82009-01-15 12:28:29 -0800635config TREE_RCU_TRACE
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700636 def_bool RCU_TRACE && ( TREE_RCU || TREE_PREEMPT_RCU )
Mike Travisc903ff82009-01-15 12:28:29 -0800637 select DEBUG_FS
638 help
Paul E. McKenneyf41d9112009-08-22 13:56:52 -0700639 This option provides tracing for the TREE_RCU and
640 TREE_PREEMPT_RCU implementations, permitting Makefile to
641 trivially select kernel/rcutree_trace.c.
Mike Travisc903ff82009-01-15 12:28:29 -0800642
Paul E. McKenney24278d12010-09-27 17:25:23 -0700643config RCU_BOOST
644 bool "Enable RCU priority boosting"
Paul E. McKenney27f4d282011-02-07 12:47:15 -0800645 depends on RT_MUTEXES && PREEMPT_RCU
Paul E. McKenney24278d12010-09-27 17:25:23 -0700646 default n
647 help
648 This option boosts the priority of preempted RCU readers that
649 block the current preemptible RCU grace period for too long.
650 This option also prevents heavy loads from blocking RCU
651 callback invocation for all flavors of RCU.
652
653 Say Y here if you are working with real-time apps or heavy loads
654 Say N here if you are unsure.
655
656config RCU_BOOST_PRIO
657 int "Real-time priority to boost RCU readers to"
658 range 1 99
659 depends on RCU_BOOST
660 default 1
661 help
Paul E. McKenneyc9336642012-04-18 16:20:18 -0700662 This option specifies the real-time priority to which long-term
663 preempted RCU readers are to be boosted. If you are working
664 with a real-time application that has one or more CPU-bound
665 threads running at a real-time priority level, you should set
666 RCU_BOOST_PRIO to a priority higher then the highest-priority
667 real-time CPU-bound thread. The default RCU_BOOST_PRIO value
668 of 1 is appropriate in the common case, which is real-time
669 applications that do not have any CPU-bound threads.
670
671 Some real-time applications might not have a single real-time
672 thread that saturates a given CPU, but instead might have
673 multiple real-time threads that, taken together, fully utilize
674 that CPU. In this case, you should set RCU_BOOST_PRIO to
675 a priority higher than the lowest-priority thread that is
676 conspiring to prevent the CPU from running any non-real-time
677 tasks. For example, if one thread at priority 10 and another
678 thread at priority 5 are between themselves fully consuming
679 the CPU time on a given CPU, then RCU_BOOST_PRIO should be
680 set to priority 6 or higher.
Paul E. McKenney24278d12010-09-27 17:25:23 -0700681
682 Specify the real-time priority, or take the default if unsure.
683
684config RCU_BOOST_DELAY
685 int "Milliseconds to delay boosting after RCU grace-period start"
686 range 0 3000
687 depends on RCU_BOOST
688 default 500
689 help
690 This option specifies the time to wait after the beginning of
691 a given grace period before priority-boosting preempted RCU
692 readers blocking that grace period. Note that any RCU reader
693 blocking an expedited RCU grace period is boosted immediately.
694
695 Accept the default if unsure.
696
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700697config RCU_NOCB_CPU
Paul E. McKenney9a5739d2013-03-28 20:48:36 -0700698 bool "Offload RCU callback processing from boot-selected CPUs"
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700699 depends on TREE_RCU || TREE_PREEMPT_RCU
700 default n
701 help
702 Use this option to reduce OS jitter for aggressive HPC or
703 real-time workloads. It can also be used to offload RCU
704 callback invocation to energy-efficient CPUs in battery-powered
705 asymmetric multiprocessors.
706
707 This option offloads callback invocation from the set of
708 CPUs specified at boot time by the rcu_nocbs parameter.
Paul E. McKenneya4889852012-12-03 08:16:28 -0800709 For each such CPU, a kthread ("rcuox/N") will be created to
710 invoke callbacks, where the "N" is the CPU being offloaded,
711 and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
712 "s" for RCU-sched. Nothing prevents this kthread from running
713 on the specified CPUs, but (1) the kthreads may be preempted
714 between each callback, and (2) affinity or cgroups can be used
715 to force the kthreads to run on whatever set of CPUs is desired.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700716
Paul E. McKenney34ed62462013-01-07 13:37:42 -0800717 Say Y here if you want to help to debug reduced OS jitter.
Paul E. McKenney3fbfbf72012-08-19 21:35:53 -0700718 Say N here if you are unsure.
719
Paul E. McKenney911af502013-02-11 10:23:27 -0800720choice
721 prompt "Build-forced no-CBs CPUs"
722 default RCU_NOCB_CPU_NONE
723 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700724 This option allows no-CBs CPUs (whose RCU callbacks are invoked
725 from kthreads rather than from softirq context) to be specified
726 at build time. Additional no-CBs CPUs may be specified by
727 the rcu_nocbs= boot parameter.
Paul E. McKenney911af502013-02-11 10:23:27 -0800728
729config RCU_NOCB_CPU_NONE
730 bool "No build_forced no-CBs CPUs"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200731 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800732 help
733 This option does not force any of the CPUs to be no-CBs CPUs.
734 Only CPUs designated by the rcu_nocbs= boot parameter will be
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700735 no-CBs CPUs, whose RCU callbacks will be invoked by per-CPU
736 kthreads whose names begin with "rcuo". All other CPUs will
737 invoke their own RCU callbacks in softirq context.
738
739 Select this option if you want to choose no-CBs CPUs at
740 boot time, for example, to allow testing of different no-CBs
741 configurations without having to rebuild the kernel each time.
Paul E. McKenney911af502013-02-11 10:23:27 -0800742
743config RCU_NOCB_CPU_ZERO
744 bool "CPU 0 is a build_forced no-CBs CPU"
Frederic Weisbecker73c30822013-05-03 01:28:12 +0200745 depends on RCU_NOCB_CPU && !NO_HZ_FULL
Paul E. McKenney911af502013-02-11 10:23:27 -0800746 help
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700747 This option forces CPU 0 to be a no-CBs CPU, so that its RCU
748 callbacks are invoked by a per-CPU kthread whose name begins
749 with "rcuo". Additional CPUs may be designated as no-CBs
750 CPUs using the rcu_nocbs= boot parameter will be no-CBs CPUs.
751 All other CPUs will invoke their own RCU callbacks in softirq
752 context.
Paul E. McKenney911af502013-02-11 10:23:27 -0800753
754 Select this if CPU 0 needs to be a no-CBs CPU for real-time
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700755 or energy-efficiency reasons, but the real reason it exists
756 is to ensure that randconfig testing covers mixed systems.
Paul E. McKenney911af502013-02-11 10:23:27 -0800757
758config RCU_NOCB_CPU_ALL
759 bool "All CPUs are build_forced no-CBs CPUs"
760 depends on RCU_NOCB_CPU
761 help
762 This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
Paul E. McKenney676c3dc2013-04-30 14:49:42 -0700763 boot parameter will be ignored. All CPUs' RCU callbacks will
764 be executed in the context of per-CPU rcuo kthreads created for
765 this purpose. Assuming that the kthreads whose names start with
766 "rcuo" are bound to "housekeeping" CPUs, this reduces OS jitter
767 on the remaining CPUs, but might decrease memory locality during
768 RCU-callback invocation, thus potentially degrading throughput.
Paul E. McKenney911af502013-02-11 10:23:27 -0800769
770 Select this if all CPUs need to be no-CBs CPUs for real-time
771 or energy-efficiency reasons.
772
773endchoice
774
Mike Travisc903ff82009-01-15 12:28:29 -0800775endmenu # "RCU Subsystem"
776
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777config IKCONFIG
Ross Birof2443ab2006-09-30 23:27:25 -0700778 tristate "Kernel .config support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 ---help---
780 This option enables the complete Linux kernel ".config" file
781 contents to be saved in the kernel. It provides documentation
782 of which kernel options are used in a running kernel or in an
783 on-disk kernel. This information can be extracted from the kernel
784 image file with the script scripts/extract-ikconfig and used as
785 input to rebuild the current kernel or to build another kernel.
786 It can also be extracted from a running kernel by reading
787 /proc/config.gz if enabled (below).
788
789config IKCONFIG_PROC
790 bool "Enable access to .config through /proc/config.gz"
791 depends on IKCONFIG && PROC_FS
792 ---help---
793 This option enables access to the kernel configuration file
794 through /proc/config.gz.
795
Alistair John Strachan794543a2007-05-08 00:31:15 -0700796config LOG_BUF_SHIFT
797 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
798 range 12 21
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700799 default 17
Alistair John Strachan794543a2007-05-08 00:31:15 -0700800 help
801 Select kernel log buffer size as a power of 2.
Adrian Bunkf17a32e2008-04-29 00:58:58 -0700802 Examples:
803 17 => 128 KB
804 16 => 64 KB
805 15 => 32 KB
806 14 => 16 KB
Alistair John Strachan794543a2007-05-08 00:31:15 -0700807 13 => 8 KB
808 12 => 4 KB
809
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800810#
811# Architectures with an unreliable sched_clock() should select this:
812#
813config HAVE_UNSTABLE_SCHED_CLOCK
814 bool
815
Stephen Boyd38ff87f2013-06-01 23:39:40 -0700816config GENERIC_SCHED_CLOCK
817 bool
818
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200819#
820# For architectures that want to enable the support for NUMA-affine scheduler
821# balancing logic:
822#
823config ARCH_SUPPORTS_NUMA_BALANCING
824 bool
825
826# For architectures that (ab)use NUMA to represent different memory regions
827# all cpu-local but of different latencies, such as SuperH.
828#
829config ARCH_WANT_NUMA_VARIABLE_LOCALITY
830 bool
831
832#
833# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
834config ARCH_WANTS_PROT_NUMA_PROT_NONE
835 bool
836
837config ARCH_USES_NUMA_PROT_NONE
838 bool
839 default y
840 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
841 depends on NUMA_BALANCING
842
Mel Gorman1a687c22012-11-22 11:16:36 +0000843config NUMA_BALANCING_DEFAULT_ENABLED
844 bool "Automatically enable NUMA aware memory/task placement"
845 default y
846 depends on NUMA_BALANCING
847 help
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400848 If set, automatic NUMA balancing will be enabled if running on a NUMA
Mel Gorman1a687c22012-11-22 11:16:36 +0000849 machine.
850
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200851config NUMA_BALANCING
852 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200853 depends on ARCH_SUPPORTS_NUMA_BALANCING
854 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
855 depends on SMP && NUMA && MIGRATION
856 help
857 This option adds support for automatic NUMA aware memory/task placement.
858 The mechanism is quite primitive and is based on migrating memory when
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400859 it has references to the node the task is running on.
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200860
861 This system will be inactive on UMA systems.
862
Li Zefan23964d22009-01-15 13:50:58 -0800863menuconfig CGROUPS
864 boolean "Control Group support"
Kirill A. Shutemov0dea1162010-03-10 15:22:20 -0800865 depends on EVENTFD
Paul Menageddbcc7e2007-10-18 23:39:30 -0700866 help
Li Zefan23964d22009-01-15 13:50:58 -0800867 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800868 use with process control subsystems such as Cpusets, CFS, memory
869 controls or device isolation.
870 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800871 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800872 - Documentation/cgroups/ (features for grouping, isolation
873 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700874
875 Say N if unsure.
876
Li Zefan23964d22009-01-15 13:50:58 -0800877if CGROUPS
878
Paul Menage006cb992007-10-18 23:39:43 -0700879config CGROUP_DEBUG
880 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700881 default n
Paul Menage006cb992007-10-18 23:39:43 -0700882 help
883 This option enables a simple cgroup subsystem that
884 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800885 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700886
Li Zefan23964d22009-01-15 13:50:58 -0800887 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700888
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700889config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800890 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800891 help
892 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700893 cgroup.
894
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700895config CGROUP_DEVICE
896 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700897 help
898 Provides a cgroup implementing whitelists for devices which
899 a process in the cgroup can mknod or open.
900
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901config CPUSETS
902 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700904 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 allow dynamically partitioning a system into sets of CPUs and
906 Memory Nodes and assigning tasks to run only within those sets.
907 This is primarily useful on large SMP or NUMA systems.
908
909 Say N if unsure.
910
Li Zefan23964d22009-01-15 13:50:58 -0800911config PROC_PID_CPUSET
912 bool "Include legacy /proc/<pid>/cpuset file"
913 depends on CPUSETS
914 default y
915
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100916config CGROUP_CPUACCT
917 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100918 help
919 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800920 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100921
Pavel Emelianove552b662008-02-07 00:13:49 -0800922config RESOURCE_COUNTERS
923 bool "Resource counters"
924 help
925 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800926 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800927
Andrew Mortonc255a452012-07-31 16:43:02 -0700928config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800929 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700930 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700931 select MM_OWNER
Balbir Singh00f0b822008-03-04 14:28:39 -0800932 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700933 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100934 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800935
936 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700937 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700938 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700939 usage tracking struct at boot. Total amount of this is printed out
940 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800941
942 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700943 sure you need the memory resource controller. Even when you enable
944 this, you can set "cgroup_disable=memory" at your boot option to
945 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800946 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800947
Balbir Singhcf475ad2008-04-29 01:00:16 -0700948 This config option also selects MM_OWNER config option, which
949 could in turn add some fork/exit overhead.
950
Andrew Mortonc255a452012-07-31 16:43:02 -0700951config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700952 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700953 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800954 help
955 Add swap management feature to memory resource controller. When you
956 enable this, you can limit mem+swap usage per cgroup. In other words,
957 when you disable this, memory resource controller has no cares to
958 usage of swap...a process can exhaust all of the swap. This extension
959 is useful when you want to avoid exhaustion swap but this itself
960 adds more overheads and consumes memory for remembering information.
961 Especially if you use 32bit system or small memory system, please
962 be careful about enabling this. When memory resource controller
963 is disabled by boot option, this will be automatically disabled and
964 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700965 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700966 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
967 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700968config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800969 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700970 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800971 default y
972 help
973 Memory Resource Controller Swap Extension comes with its price in
974 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700975 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -0700976 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -0800977 parameter should have this option unselected.
978 For those who want to have the feature enabled by default should
979 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700980 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700981config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700982 bool "Memory Resource Controller Kernel Memory accounting"
983 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800984 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000985 help
986 The Kernel Memory extension for Memory Resource Controller can limit
987 the amount of memory used by kernel objects in the system. Those are
988 fundamentally different from the entities handled by the standard
989 Memory Controller, which are page-based, and can be swapped. Users of
990 the kmem extension can use it to guarantee that no group of processes
991 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800992
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700993config CGROUP_HUGETLB
994 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -0700995 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700996 default n
997 help
998 Provides a cgroup Resource Controller for HugeTLB pages.
999 When you enable this, you can put a per cgroup limit on HugeTLB usage.
1000 The limit is enforced during page fault. Since HugeTLB doesn't
1001 support page reclaim, enforcing the limit at page fault time implies
1002 that, the application will get SIGBUS signal if it tries to access
1003 HugeTLB pages beyond its limit. This requires the application to know
1004 beforehand how much HugeTLB pages it would require for its use. The
1005 control group is tracked in the third page lru pointer. This means
1006 that we cannot use the controller with huge page less than 3 pages.
1007
Stephane Eraniane5d13672011-02-14 11:20:01 +02001008config CGROUP_PERF
1009 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
1010 depends on PERF_EVENTS && CGROUPS
1011 help
1012 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +08001013 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001014 designated cpu.
1015
1016 Say N if unsure.
1017
Dhaval Giani7c941432010-01-20 13:26:18 +01001018menuconfig CGROUP_SCHED
1019 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001020 default n
1021 help
1022 This feature lets CPU scheduler recognize task groups and control CPU
1023 bandwidth allocation to such task groups. It uses cgroups to group
1024 tasks.
1025
1026if CGROUP_SCHED
1027config FAIR_GROUP_SCHED
1028 bool "Group scheduling for SCHED_OTHER"
1029 depends on CGROUP_SCHED
1030 default CGROUP_SCHED
1031
Paul Turnerab84d312011-07-21 09:43:28 -07001032config CFS_BANDWIDTH
1033 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001034 depends on FAIR_GROUP_SCHED
1035 default n
1036 help
1037 This option allows users to define CPU bandwidth rates (limits) for
1038 tasks running within the fair group scheduler. Groups with no limit
1039 set are considered to be unconstrained and will run with no
1040 restriction.
1041 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1042
Dhaval Giani7c941432010-01-20 13:26:18 +01001043config RT_GROUP_SCHED
1044 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001045 depends on CGROUP_SCHED
1046 default n
1047 help
1048 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001049 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001050 schedule realtime tasks for non-root users until you allocate
1051 realtime bandwidth for them.
1052 See Documentation/scheduler/sched-rt-group.txt for more information.
1053
1054endif #CGROUP_SCHED
1055
Vivek Goyalafc24d42010-04-26 19:27:56 +02001056config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001057 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001058 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001059 default n
1060 ---help---
1061 Generic block IO controller cgroup interface. This is the common
1062 cgroup interface which should be used by various IO controlling
1063 policies.
1064
1065 Currently, CFQ IO scheduler uses it to recognize task groups and
1066 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001067 to such task groups. It is also used by bio throttling logic in
1068 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001069
1070 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001071 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001072 enabling proportional weight division of disk bandwidth in CFQ, set
1073 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001074 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001075
1076 See Documentation/cgroups/blkio-controller.txt for more information.
1077
1078config DEBUG_BLK_CGROUP
1079 bool "Enable Block IO controller debugging"
1080 depends on BLK_CGROUP
1081 default n
1082 ---help---
1083 Enable some debugging help. Currently it exports additional stat
1084 files in a cgroup which can be useful for debugging.
1085
Li Zefan23964d22009-01-15 13:50:58 -08001086endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001087
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001088config CHECKPOINT_RESTORE
1089 bool "Checkpoint/restore support" if EXPERT
1090 default n
1091 help
1092 Enables additional kernel features in a sake of checkpoint/restore.
1093 In particular it adds auxiliary prctl codes to setup process text,
1094 data and heap segment sizes, and a few additional /proc filesystem
1095 entries.
1096
1097 If unsure, say N here.
1098
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001099menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001100 bool "Namespaces support" if EXPERT
1101 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001102 help
1103 Provides the way to make tasks work with different objects using
1104 the same id. For example same IPC id may refer to different objects
1105 or same user id or pid may refer to different tasks when used in
1106 different namespaces.
1107
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001108if NAMESPACES
1109
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001110config UTS_NS
1111 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001112 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001113 help
1114 In this namespace tasks see different info provided with the
1115 uname() system call
1116
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001117config IPC_NS
1118 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001119 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001120 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001121 help
1122 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001123 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001124
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001125config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001126 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001127 select UIDGID_STRICT_TYPE_CHECKS
Eric W. Biedermane1c972b2012-04-21 04:09:01 -07001128
Eric W. Biederman5673a942011-11-17 10:23:55 -08001129 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001130 help
1131 This allows containers, i.e. vservers, to use user namespaces
1132 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001133
1134 When user namespaces are enabled in the kernel it is
1135 recommended that the MEMCG and MEMCG_KMEM options also be
1136 enabled and that user-space use the memory control groups to
1137 limit the amount of memory a memory unprivileged users can
1138 use.
1139
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001140 If unsure, say N.
1141
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001142config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001143 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001144 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001145 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001146 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001147 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001148 pid namespaces. This is a building block of containers.
1149
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001150config NET_NS
1151 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001152 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001153 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001154 help
1155 Allow user space to create what appear to be multiple instances
1156 of the network stack.
1157
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001158endif # NAMESPACES
1159
Eric W. Biederman5673a942011-11-17 10:23:55 -08001160config UIDGID_STRICT_TYPE_CHECKS
1161 bool "Require conversions between uid/gids and their internal representation"
1162 default n
1163 help
1164 While the nececessary conversions are being added to all subsystems this option allows
1165 the code to continue to build for unconverted subsystems.
1166
1167 Say Y here if you want the strict type checking enabled
1168
Mike Galbraith5091faa2010-11-30 14:18:03 +01001169config SCHED_AUTOGROUP
1170 bool "Automatic process group scheduling"
1171 select EVENTFD
1172 select CGROUPS
1173 select CGROUP_SCHED
1174 select FAIR_GROUP_SCHED
1175 help
1176 This option optimizes the scheduler for common desktop workloads by
1177 automatically creating and populating task groups. This separation
1178 of workloads isolates aggressive CPU burners (like build jobs) from
1179 desktop applications. Task group autogeneration is currently based
1180 upon task session.
1181
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001182config MM_OWNER
1183 bool
1184
1185config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001186 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001187 depends on SYSFS
1188 default n
1189 help
1190 This option adds code that switches the layout of the "block" class
1191 devices, to not show up in /sys/class/block/, but only in
1192 /sys/block/.
1193
1194 This switch is only active when the sysfs.deprecated=1 boot option is
1195 passed or the SYSFS_DEPRECATED_V2 option is set.
1196
1197 This option allows new kernels to run on old distributions and tools,
1198 which might get confused by /sys/class/block/. Since 2007/2008 all
1199 major distributions and tools handle this just fine.
1200
1201 Recent distributions and userspace tools after 2009/2010 depend on
1202 the existence of /sys/class/block/, and will not work with this
1203 option enabled.
1204
1205 Only if you are using a new kernel on an old distribution, you might
1206 need to say Y here.
1207
1208config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001209 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001210 default n
1211 depends on SYSFS
1212 depends on SYSFS_DEPRECATED
1213 help
1214 Enable deprecated sysfs by default.
1215
1216 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1217 option.
1218
1219 Only if you are using a new kernel on an old distribution, you might
1220 need to say Y here. Even then, odds are you would not need it
1221 enabled, you can always pass the boot option if absolutely necessary.
1222
1223config RELAY
1224 bool "Kernel->user space relay support (formerly relayfs)"
1225 help
1226 This option enables support for relay interface support in
1227 certain file systems (such as debugfs).
1228 It is designed to provide an efficient mechanism for tools and
1229 facilities to relay large amounts of data from kernel space to
1230 user space.
1231
1232 If unsure, say N.
1233
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001234config BLK_DEV_INITRD
1235 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1236 depends on BROKEN || !FRV
1237 help
1238 The initial RAM filesystem is a ramfs which is loaded by the
1239 boot loader (loadlin or lilo) and that is mounted as root
1240 before the normal boot procedure. It is typically used to
1241 load modules needed to mount the "real" root file system,
1242 etc. See <file:Documentation/initrd.txt> for details.
1243
1244 If RAM disk support (BLK_DEV_RAM) is also included, this
1245 also enables initial RAM disk (initrd) support and adds
1246 15 Kbytes (more on some other architectures) to the kernel size.
1247
1248 If unsure say Y.
1249
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001250if BLK_DEV_INITRD
1251
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001252source "usr/Kconfig"
1253
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001254endif
1255
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001256config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001257 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001258 help
1259 Enabling this option will pass "-Os" instead of "-O2" to gcc
1260 resulting in a smaller kernel.
1261
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001262 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001263
Randy Dunlap08470622006-09-30 23:28:13 -07001264config SYSCTL
1265 bool
1266
Randy Dunlapb943c462009-03-10 12:55:46 -07001267config ANON_INODES
1268 bool
1269
Mike Frysinger657a5202013-04-30 15:28:45 -07001270config HAVE_UID16
1271 bool
1272
1273config SYSCTL_EXCEPTION_TRACE
1274 bool
1275 help
1276 Enable support for /proc/sys/debug/exception-trace.
1277
1278config SYSCTL_ARCH_UNALIGN_NO_WARN
1279 bool
1280 help
1281 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1282 Allows arch to define/use @no_unaligned_warning to possibly warn
1283 about unaligned access emulation going on under the hood.
1284
1285config SYSCTL_ARCH_UNALIGN_ALLOW
1286 bool
1287 help
1288 Enable support for /proc/sys/kernel/unaligned-trap
1289 Allows arches to define/use @unaligned_enabled to runtime toggle
1290 the unaligned access emulation.
1291 see arch/parisc/kernel/unaligned.c for reference
1292
Mike Frysinger657a5202013-04-30 15:28:45 -07001293config HAVE_PCSPKR_PLATFORM
1294 bool
1295
David Rientjes6a108a12011-01-20 14:44:16 -08001296menuconfig EXPERT
1297 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001298 # Unhide debug options, to make the on-by-default options visible
1299 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 help
1301 This option allows certain base kernel options and settings
1302 to be disabled or tweaked. This is for specialized
1303 environments which can tolerate a "non-standard" kernel.
1304 Only use this if you really know what you are doing.
1305
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001306config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001307 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001308 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001309 default y
1310 help
1311 This enables the legacy 16-bit UID syscall wrappers.
1312
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001313config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001314 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001315 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001316 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001317 select SYSCTL
1318 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001319 sys_sysctl uses binary paths that have been found challenging
1320 to properly maintain and use. The interface in /proc/sys
1321 using paths with ascii names is now the primary path to this
1322 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001323
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001324 Almost nothing using the binary sysctl interface so if you are
1325 trying to save some space it is probably safe to disable this,
1326 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001327
WANG Congc736de62011-11-02 13:39:25 -07001328 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001329
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001331 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 default y
1333 help
1334 Say Y here to let the kernel print out symbolic crash information and
1335 symbolic stack backtraces. This increases the size of the kernel
1336 somewhat, as all symbols have to be loaded into the kernel image.
1337
1338config KALLSYMS_ALL
1339 bool "Include all symbols in kallsyms"
1340 depends on DEBUG_KERNEL && KALLSYMS
1341 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001342 Normally kallsyms only contains the symbols of functions for nicer
1343 OOPS messages and backtraces (i.e., symbols from the text and inittext
1344 sections). This is sufficient for most cases. And only in very rare
1345 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1346 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001348 This option makes sure that all symbols are loaded into the kernel
1349 image (i.e., symbols from all sections) in cost of increased kernel
1350 size (depending on the kernel configuration, it may be 300KiB or
1351 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001353 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001354
1355config PRINTK
1356 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001357 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001358 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001359 help
1360 This option enables normal printk support. Removing it
1361 eliminates most of the message strings from the kernel image
1362 and makes the kernel more or less silent. As this makes it
1363 very difficult to diagnose system problems, saying N here is
1364 strongly discouraged.
1365
Matt Mackallc8538a72005-05-01 08:59:01 -07001366config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001367 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001368 default y
1369 help
1370 Disabling this option eliminates support for BUG and WARN, reducing
1371 the size of your kernel image and potentially quietly ignoring
1372 numerous fatal conditions. You should only consider disabling this
1373 option for embedded systems with no facilities for reporting errors.
1374 Just say Y.
1375
Matt Mackall708e9a72006-01-08 01:05:25 -08001376config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001377 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001378 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001379 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001380 help
1381 Enable support for generating core dumps. Disabling saves about 4k.
1382
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001383
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001384config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001385 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001386 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001387 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001388 default y
1389 help
1390 This option allows to disable the internal PC-Speaker
1391 support, saving some memory.
1392
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393config BASE_FULL
1394 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001395 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396 help
1397 Disabling this option reduces the size of miscellaneous core
1398 kernel data structures. This saves memory on small machines,
1399 but may reduce performance.
1400
1401config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001402 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001404 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 help
1406 Disabling this option will cause the kernel to be built without
1407 support for "fast userspace mutexes". The resulting kernel may not
1408 run glibc-based applications correctly.
1409
1410config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001411 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001413 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414 help
1415 Disabling this option will cause the kernel to be built without
1416 support for epoll family of system calls.
1417
Davide Libenzifba2afa2007-05-10 22:23:13 -07001418config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001419 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001420 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001421 default y
1422 help
1423 Enable the signalfd() system call that allows to receive signals
1424 on a file descriptor.
1425
1426 If unsure, say Y.
1427
Davide Libenzib215e282007-05-10 22:23:16 -07001428config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001429 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001430 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001431 default y
1432 help
1433 Enable the timerfd() system call that allows to receive timer
1434 events on a file descriptor.
1435
1436 If unsure, say Y.
1437
Davide Libenzie1ad7462007-05-10 22:23:19 -07001438config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001439 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001440 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001441 default y
1442 help
1443 Enable the eventfd() system call that allows to receive both
1444 kernel notification (ie. KAIO) or userspace notifications.
1445
1446 If unsure, say Y.
1447
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001449 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450 default y
1451 depends on MMU
1452 help
1453 The shmem is an internal filesystem used to manage shared memory.
1454 It is backed by swap and manages resource limits. It is also exported
1455 to userspace as tmpfs if TMPFS is enabled. Disabling this
1456 option replaces shmem and tmpfs with the much simpler ramfs code,
1457 which may be appropriate on small systems without swap.
1458
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001459config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001460 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001461 default y
1462 help
1463 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001464 by some high performance threaded applications. Disabling
1465 this option saves about 7k.
1466
1467config PCI_QUIRKS
1468 default y
1469 bool "Enable PCI quirk workarounds" if EXPERT
1470 depends on PCI
1471 help
1472 This enables workarounds for various PCI chipset
1473 bugs/quirks. Disable this only if your target machine is
1474 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001475
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001476config EMBEDDED
1477 bool "Embedded system"
1478 select EXPERT
1479 help
1480 This option should be enabled if compiling the kernel for
1481 an embedded system so certain expert options are available
1482 for configuration.
1483
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001484config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001485 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001486 help
1487 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001488
Peter Zijlstra906010b2009-09-21 16:08:49 +02001489config PERF_USE_VMALLOC
1490 bool
1491 help
1492 See tools/perf/design.txt for details
1493
Ingo Molnar57c0c152009-09-21 12:20:38 +02001494menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001495
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001496config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001497 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001498 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001499 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001500 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001501 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001502 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001503 Enable kernel support for various performance events provided
1504 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001505
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001506 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001507 use of generic tracepoints.
1508
1509 Most modern CPUs support performance events via performance
1510 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001511 types of hw events: such as instructions executed, cachemisses
1512 suffered, or branches mis-predicted - without slowing down the
1513 kernel or applications. These registers can also trigger interrupts
1514 when a threshold number of events have passed - and can thus be
1515 used to profile the code that runs on that CPU.
1516
Ingo Molnar57c0c152009-09-21 12:20:38 +02001517 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001518 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001519 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001520 provides per task and per CPU counters, and it provides event
1521 capabilities on top of those.
1522
1523 Say Y if unsure.
1524
Peter Zijlstra906010b2009-09-21 16:08:49 +02001525config DEBUG_PERF_USE_VMALLOC
1526 default n
1527 bool "Debug: use vmalloc to back perf mmap() buffers"
1528 depends on PERF_EVENTS && DEBUG_KERNEL
1529 select PERF_USE_VMALLOC
1530 help
1531 Use vmalloc memory to back perf mmap() buffers.
1532
1533 Mostly useful for debugging the vmalloc code on platforms
1534 that don't require it.
1535
1536 Say N if unsure.
1537
Thomas Gleixner0793a612008-12-04 20:12:29 +01001538endmenu
1539
Christoph Lameterf8891e52006-06-30 01:55:45 -07001540config VM_EVENT_COUNTERS
1541 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001542 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001543 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001544 VM event counters are needed for event counts to be shown.
1545 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001546 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001547 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001548
Christoph Lameter41ecc552007-05-09 02:32:44 -07001549config SLUB_DEBUG
1550 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001551 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001552 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001553 help
1554 SLUB has extensive debug support features. Disabling these can
1555 result in significant savings in code size. This also disables
1556 SLUB sysfs support. /sys/slab will not exist and there will be
1557 no support for cache validation etc.
1558
Randy Dunlapb943c462009-03-10 12:55:46 -07001559config COMPAT_BRK
1560 bool "Disable heap randomization"
1561 default y
1562 help
1563 Randomizing heap placement makes heap exploits harder, but it
1564 also breaks ancient binaries (including anything libc5 based).
1565 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001566 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001567 /proc/sys/kernel/randomize_va_space to 2.
1568
1569 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1570
Christoph Lameter81819f02007-05-06 14:49:36 -07001571choice
1572 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001573 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001574 help
1575 This option allows to select a slab allocator.
1576
1577config SLAB
1578 bool "SLAB"
1579 help
1580 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001581 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001582 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001583
1584config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001585 bool "SLUB (Unqueued Allocator)"
1586 help
1587 SLUB is a slab allocator that minimizes cache line usage
1588 instead of managing queues of cached objects (SLAB approach).
1589 Per cpu caching is realized using slabs of objects instead
1590 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001591 and has enhanced diagnostics. SLUB is the default choice for
1592 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001593
1594config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001595 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001596 bool "SLOB (Simple Allocator)"
1597 help
Matt Mackall37291452008-02-04 22:29:38 -08001598 SLOB replaces the stock allocator with a drastically simpler
1599 allocator. SLOB is generally more space efficient but
1600 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001601
1602endchoice
1603
Joonsoo Kim345c9052013-06-19 14:05:52 +09001604config SLUB_CPU_PARTIAL
1605 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001606 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001607 bool "SLUB per cpu partial cache"
1608 help
1609 Per cpu partial caches accellerate objects allocation and freeing
1610 that is local to a processor at the price of more indeterminism
1611 in the latency of the free. On overflow these caches will be cleared
1612 which requires the taking of locks that may cause latency spikes.
1613 Typically one would choose no for a realtime system.
1614
Jie Zhangea637632009-12-14 18:00:02 -08001615config MMAP_ALLOW_UNINITIALIZED
1616 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001617 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001618 default n
1619 help
1620 Normally, and according to the Linux spec, anonymous memory obtained
1621 from mmap() has it's contents cleared before it is passed to
1622 userspace. Enabling this config option allows you to request that
1623 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1624 providing a huge performance boost. If this option is not enabled,
1625 then the flag will be ignored.
1626
1627 This is taken advantage of by uClibc's malloc(), and also by
1628 ELF-FDPIC binfmt's brk and stack allocator.
1629
1630 Because of the obvious security issues, this option should only be
1631 enabled on embedded devices where you control what is run in
1632 userspace. Since that isn't generally a problem on no-MMU systems,
1633 it is normally safe to say Y here.
1634
1635 See Documentation/nommu-mmap.txt for more information.
1636
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001637config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001638 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001639 help
1640 Say Y here to enable the extended profiling support mechanisms used
1641 by profilers such as OProfile.
1642
Ingo Molnar5f87f112008-07-23 14:15:22 +02001643#
1644# Place an empty function call at each tracepoint site. Can be
1645# dynamically changed for a probe function.
1646#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001647config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001648 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001649
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001650source "arch/Kconfig"
1651
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652endmenu # General setup
1653
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001654config HAVE_GENERIC_DMA_COHERENT
1655 bool
1656 default n
1657
Linus Torvalds158a9622008-01-02 13:04:48 -08001658config SLABINFO
1659 bool
1660 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001661 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001662 default y
1663
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001664config RT_MUTEXES
1665 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001666
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667config BASE_SMALL
1668 int
1669 default 0 if BASE_FULL
1670 default 1 if !BASE_FULL
1671
Jan Engelhardt66da5732007-07-15 23:39:29 -07001672menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001674 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 help
1676 Kernel modules are small pieces of compiled code which can
1677 be inserted in the running kernel, rather than being
1678 permanently built into the kernel. You use the "modprobe"
1679 tool to add (and sometimes remove) them. If you say Y here,
1680 many parts of the kernel can be built as modules (by
1681 answering M instead of Y where indicated): this is most
1682 useful for infrequently used options which are not required
1683 for booting. For more information, see the man pages for
1684 modprobe, lsmod, modinfo, insmod and rmmod.
1685
1686 If you say Y here, you will need to run "make
1687 modules_install" to put the modules under /lib/modules/
1688 where modprobe can find them (you may need to be root to do
1689 this).
1690
1691 If unsure, say Y.
1692
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001693if MODULES
1694
Linus Torvalds826e4502008-05-04 17:04:16 -07001695config MODULE_FORCE_LOAD
1696 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001697 default n
1698 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001699 Allow loading of modules without version information (ie. modprobe
1700 --force). Forced module loading sets the 'F' (forced) taint flag and
1701 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001702
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703config MODULE_UNLOAD
1704 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 help
1706 Without this option you will not be able to unload any
1707 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001708 anyway), which makes your kernel smaller, faster
1709 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001710
1711config MODULE_FORCE_UNLOAD
1712 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001713 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 help
1715 This option allows you to force a module to unload, even if the
1716 kernel believes it is unsafe: the kernel will remove the module
1717 without waiting for anyone to stop using it (using the -f option to
1718 rmmod). This is mainly for kernel developers and desperate users.
1719 If unsure, say N.
1720
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001722 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 help
1724 Usually, you have to use modules compiled with your kernel.
1725 Saying Y here makes it sometimes possible to use modules
1726 compiled for different kernels, by adding enough information
1727 to the modules to (hopefully) spot any changes which would
1728 make them incompatible with the kernel you are running. If
1729 unsure, say N.
1730
1731config MODULE_SRCVERSION_ALL
1732 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 help
1734 Modules which contain a MODULE_VERSION get an extra "srcversion"
1735 field inserted into their modinfo section, which contains a
1736 sum of the source files which made it. This helps maintainers
1737 see exactly which source was used to build a module (since
1738 others sometimes change the module source without updating
1739 the version). With this option, such a "srcversion" field
1740 will be created for all modules. If unsure, say N.
1741
Rusty Russell106a4ee2012-09-26 10:09:40 +01001742config MODULE_SIG
1743 bool "Module signature verification"
1744 depends on MODULES
David Howells48ba2462012-09-26 10:11:03 +01001745 select KEYS
1746 select CRYPTO
1747 select ASYMMETRIC_KEY_TYPE
1748 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1749 select PUBLIC_KEY_ALGO_RSA
1750 select ASN1
1751 select OID_REGISTRY
1752 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001753 help
1754 Check modules for valid signatures upon load: the signature
1755 is simply appended to the module. For more information see
1756 Documentation/module-signing.txt.
1757
David Howellsea0b6dc2012-09-26 10:09:50 +01001758 !!!WARNING!!! If you enable this option, you MUST make sure that the
1759 module DOES NOT get stripped after being signed. This includes the
1760 debuginfo strip done by some packagers (such as rpmbuild) and
1761 inclusion into an initramfs that wants the module size reduced.
1762
Rusty Russell106a4ee2012-09-26 10:09:40 +01001763config MODULE_SIG_FORCE
1764 bool "Require modules to be validly signed"
1765 depends on MODULE_SIG
1766 help
1767 Reject unsigned modules or signed modules for which we don't have a
1768 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001769
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301770config MODULE_SIG_ALL
1771 bool "Automatically sign all modules"
1772 default y
1773 depends on MODULE_SIG
1774 help
1775 Sign all modules during make modules_install. Without this option,
1776 modules must be signed manually, using the scripts/sign-file tool.
1777
1778comment "Do not forget to sign required modules with scripts/sign-file"
1779 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1780
David Howellsea0b6dc2012-09-26 10:09:50 +01001781choice
1782 prompt "Which hash algorithm should modules be signed with?"
1783 depends on MODULE_SIG
1784 help
1785 This determines which sort of hashing algorithm will be used during
1786 signature generation. This algorithm _must_ be built into the kernel
1787 directly so that signature verification can take place. It is not
1788 possible to load a signed module containing the algorithm to check
1789 the signature on that module.
1790
1791config MODULE_SIG_SHA1
1792 bool "Sign modules with SHA-1"
1793 select CRYPTO_SHA1
1794
1795config MODULE_SIG_SHA224
1796 bool "Sign modules with SHA-224"
1797 select CRYPTO_SHA256
1798
1799config MODULE_SIG_SHA256
1800 bool "Sign modules with SHA-256"
1801 select CRYPTO_SHA256
1802
1803config MODULE_SIG_SHA384
1804 bool "Sign modules with SHA-384"
1805 select CRYPTO_SHA512
1806
1807config MODULE_SIG_SHA512
1808 bool "Sign modules with SHA-512"
1809 select CRYPTO_SHA512
1810
1811endchoice
1812
Michal Marek22753672013-01-25 13:41:00 +10301813config MODULE_SIG_HASH
1814 string
1815 depends on MODULE_SIG
1816 default "sha1" if MODULE_SIG_SHA1
1817 default "sha224" if MODULE_SIG_SHA224
1818 default "sha256" if MODULE_SIG_SHA256
1819 default "sha384" if MODULE_SIG_SHA384
1820 default "sha512" if MODULE_SIG_SHA512
1821
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001822endif # MODULES
1823
Rusty Russell98a79d62008-12-13 21:19:41 +10301824config INIT_ALL_POSSIBLE
1825 bool
1826 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301827 Back when each arch used to define their own cpu_online_mask and
1828 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301829 with all 1s, and others with all 0s. When they were centralised,
1830 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001831 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301832
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833config STOP_MACHINE
1834 bool
1835 default y
1836 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1837 help
1838 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001839
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001840source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001841
1842config PREEMPT_NOTIFIERS
1843 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001844
Steffen Klassert16295be2010-01-06 19:47:10 +11001845config PADATA
1846 depends on SMP
1847 bool
1848
Andi Kleen754b7b62012-10-04 17:11:27 -07001849# Can be selected by architectures with broken toolchains
1850# that get confused by correct const<->read_only section
1851# mappings
1852config BROKEN_RODATA
1853 bool
1854
David Howells4520c6a2012-09-21 23:31:13 +01001855config ASN1
1856 tristate
1857 help
1858 Build a simple ASN.1 grammar compiler that produces a bytecode output
1859 that can be interpreted by the ASN.1 stream decoder and used to
1860 inform it as to what tags are to be expected in a stream and what
1861 functions to call on what tags.
1862
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001863source "kernel/Kconfig.locks"