blob: 9d3585bb2a7a3cbb58234d24761f597b0af95c7c [file] [log] [blame]
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
Josh Triplett69369a72014-04-03 14:48:27 -0700276config USELIB
277 bool "uselib syscall"
278 default y
279 help
280 This option enables the uselib syscall, a system call used in the
281 dynamic linker from libc5 and earlier. glibc does not use this
282 system call. If you intend to run programs built on libc5 or
283 earlier, you may need to enable this syscall. Current systems
284 running glibc can safely disable this.
285
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286config AUDIT
287 bool "Auditing support"
Chris Wright804a6a492005-05-11 10:52:45 +0100288 depends on NET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 help
290 Enable auditing infrastructure that can be used with another
291 kernel subsystem, such as SELinux (which requires this for
292 logging of avc messages output). Does not do system-call
293 auditing without CONFIG_AUDITSYSCALL.
294
AKASHI Takahiro7a017722014-02-25 18:16:24 +0900295config HAVE_ARCH_AUDITSYSCALL
296 bool
297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298config AUDITSYSCALL
299 bool "Enable system-call auditing support"
AKASHI Takahiro7a017722014-02-25 18:16:24 +0900300 depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 default y if SECURITY_SELINUX
302 help
303 Enable low-overhead system-call auditing infrastructure that
304 can be used independently or with another kernel subsystem,
Eric Paris67640b62009-12-17 20:12:06 -0500305 such as SELinux.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Eric Paris939a67f2009-12-17 20:12:06 -0500307config AUDIT_WATCH
308 def_bool y
309 depends on AUDITSYSCALL
310 select FSNOTIFY
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
Al Viro74c3cbe2007-07-22 08:04:18 -0400312config AUDIT_TREE
313 def_bool y
Eric Paris63c882a2009-05-21 17:02:01 -0400314 depends on AUDITSYSCALL
Eric Paris28a3a7e2009-12-17 20:12:05 -0500315 select FSNOTIFY
Al Viro74c3cbe2007-07-22 08:04:18 -0400316
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000317source "kernel/irq/Kconfig"
Thomas Gleixner764e0da2012-05-21 23:16:18 +0200318source "kernel/time/Kconfig"
Thomas Gleixnerd9817eb2010-09-27 12:45:59 +0000319
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200320menu "CPU/Task time and stats accounting"
321
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200322config VIRT_CPU_ACCOUNTING
323 bool
324
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200325choice
326 prompt "Cputime accounting"
327 default TICK_CPU_ACCOUNTING if !PPC64
Stephen Rothwell02fc8d32013-02-08 14:19:38 +1100328 default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200329
330# Kind of a stub config for the pure tick based cputime accounting
331config TICK_CPU_ACCOUNTING
332 bool "Simple tick based cputime accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200333 depends on !S390 && !NO_HZ_FULL
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200334 help
335 This is the basic tick based cputime accounting that maintains
336 statistics about user, system and idle time spent on per jiffies
337 granularity.
338
339 If unsure, say Y.
340
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200341config VIRT_CPU_ACCOUNTING_NATIVE
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200342 bool "Deterministic task and CPU time accounting"
Frederic Weisbeckerc58b0df2013-04-26 15:16:31 +0200343 depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200344 select VIRT_CPU_ACCOUNTING
Frederic Weisbecker391dc692012-09-09 14:22:07 +0200345 help
346 Select this option to enable more accurate task and CPU time
347 accounting. This is done by reading a CPU counter on each
348 kernel entry and exit and on transitions within the kernel
349 between system, softirq and hardirq state, so there is a
350 small performance impact. In the case of s390 or IBM POWER > 5,
351 this also enables accounting of stolen time on logically-partitioned
352 systems.
353
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200354config VIRT_CPU_ACCOUNTING_GEN
355 bool "Full dynticks CPU time accounting"
Kevin Hilmanff3fb252013-09-16 15:28:19 -0700356 depends on HAVE_CONTEXT_TRACKING
Kevin Hilman554b0002013-09-16 15:28:21 -0700357 depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
Frederic Weisbeckerabf917c2012-07-25 07:56:04 +0200358 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
Paul Gortmaker99c8b1e2013-10-24 10:07:47 -0400548 Say Y only if you're working on the development of an
Frederic Weisbeckerd84d27a2013-07-24 21:59:29 +0200549 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
Peter Zijlstrabe5e6102013-11-18 18:27:06 +0100825#
826# For architectures that know their GCC __int128 support is sound
827#
828config ARCH_SUPPORTS_INT128
829 bool
830
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200831# For architectures that (ab)use NUMA to represent different memory regions
832# all cpu-local but of different latencies, such as SuperH.
833#
834config ARCH_WANT_NUMA_VARIABLE_LOCALITY
835 bool
836
837#
838# For architectures that are willing to define _PAGE_NUMA as _PAGE_PROTNONE
839config ARCH_WANTS_PROT_NUMA_PROT_NONE
840 bool
841
842config ARCH_USES_NUMA_PROT_NONE
843 bool
844 default y
845 depends on ARCH_WANTS_PROT_NUMA_PROT_NONE
846 depends on NUMA_BALANCING
847
Mel Gorman1a687c22012-11-22 11:16:36 +0000848config NUMA_BALANCING_DEFAULT_ENABLED
849 bool "Automatically enable NUMA aware memory/task placement"
850 default y
851 depends on NUMA_BALANCING
852 help
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400853 If set, automatic NUMA balancing will be enabled if running on a NUMA
Mel Gorman1a687c22012-11-22 11:16:36 +0000854 machine.
855
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200856config NUMA_BALANCING
857 bool "Memory placement aware NUMA scheduler"
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200858 depends on ARCH_SUPPORTS_NUMA_BALANCING
859 depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
860 depends on SMP && NUMA && MIGRATION
861 help
862 This option adds support for automatic NUMA aware memory/task placement.
863 The mechanism is quite primitive and is based on migrating memory when
Paul Gortmaker6d56a412013-08-13 11:06:50 -0400864 it has references to the node the task is running on.
Andrea Arcangelibe3a7282012-10-04 01:50:47 +0200865
866 This system will be inactive on UMA systems.
867
Li Zefan23964d22009-01-15 13:50:58 -0800868menuconfig CGROUPS
869 boolean "Control Group support"
Tejun Heo2bd59d42014-02-11 11:52:49 -0500870 select KERNFS
Paul Menageddbcc7e2007-10-18 23:39:30 -0700871 help
Li Zefan23964d22009-01-15 13:50:58 -0800872 This option adds support for grouping sets of processes together, for
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800873 use with process control subsystems such as Cpusets, CFS, memory
874 controls or device isolation.
875 See
KAMEZAWA Hiroyuki5cdc38f2009-01-07 18:07:30 -0800876 - Documentation/scheduler/sched-design-CFS.txt (CFS)
Li Zefan45ce80f2009-01-15 13:50:59 -0800877 - Documentation/cgroups/ (features for grouping, isolation
878 and resource control)
Paul Menageddbcc7e2007-10-18 23:39:30 -0700879
880 Say N if unsure.
881
Li Zefan23964d22009-01-15 13:50:58 -0800882if CGROUPS
883
Paul Menage006cb992007-10-18 23:39:43 -0700884config CGROUP_DEBUG
885 bool "Example debug cgroup subsystem"
Paul Menage418d7d82008-04-29 01:00:05 -0700886 default n
Paul Menage006cb992007-10-18 23:39:43 -0700887 help
888 This option enables a simple cgroup subsystem that
889 exports useful debugging information about the cgroups
Li Zefan23964d22009-01-15 13:50:58 -0800890 framework.
Paul Menage006cb992007-10-18 23:39:43 -0700891
Li Zefan23964d22009-01-15 13:50:58 -0800892 Say N if unsure.
Paul Menage006cb992007-10-18 23:39:43 -0700893
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700894config CGROUP_FREEZER
Li Zefan23964d22009-01-15 13:50:58 -0800895 bool "Freezer cgroup subsystem"
Li Zefan23964d22009-01-15 13:50:58 -0800896 help
897 Provides a way to freeze and unfreeze all tasks in a
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700898 cgroup.
899
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700900config CGROUP_DEVICE
901 bool "Device controller for cgroups"
Serge E. Hallyn08ce5f12008-04-29 01:00:10 -0700902 help
903 Provides a cgroup implementing whitelists for devices which
904 a process in the cgroup can mknod or open.
905
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906config CPUSETS
907 bool "Cpuset support"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 help
Randy Dunlapd9fd8a62005-07-27 11:45:11 -0700909 This option will let you create and manage CPUSETs which
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 allow dynamically partitioning a system into sets of CPUs and
911 Memory Nodes and assigning tasks to run only within those sets.
912 This is primarily useful on large SMP or NUMA systems.
913
914 Say N if unsure.
915
Li Zefan23964d22009-01-15 13:50:58 -0800916config PROC_PID_CPUSET
917 bool "Include legacy /proc/<pid>/cpuset file"
918 depends on CPUSETS
919 default y
920
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100921config CGROUP_CPUACCT
922 bool "Simple CPU accounting cgroup subsystem"
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100923 help
924 Provides a simple Resource Controller for monitoring the
Li Zefan23964d22009-01-15 13:50:58 -0800925 total CPU consumed by the tasks in a cgroup.
Srivatsa Vaddagirid842de82007-12-02 20:04:49 +0100926
Pavel Emelianove552b662008-02-07 00:13:49 -0800927config RESOURCE_COUNTERS
928 bool "Resource counters"
929 help
930 This option enables controller independent resource accounting
Li Zefan23964d22009-01-15 13:50:58 -0800931 infrastructure that works with cgroups.
Pavel Emelianove552b662008-02-07 00:13:49 -0800932
Andrew Mortonc255a452012-07-31 16:43:02 -0700933config MEMCG
Balbir Singh00f0b822008-03-04 14:28:39 -0800934 bool "Memory Resource Controller for Control Groups"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -0700935 depends on RESOURCE_COUNTERS
Balbir Singhcf475ad2008-04-29 01:00:16 -0700936 select MM_OWNER
Tejun Heo79bd9812013-11-22 18:20:42 -0500937 select EVENTFD
Balbir Singh00f0b822008-03-04 14:28:39 -0800938 help
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700939 Provides a memory resource controller that manages both anonymous
Thadeu Lima de Souza Cascardo21acb9c2009-02-04 10:12:08 +0100940 memory and page cache. (See Documentation/cgroups/memory.txt)
Balbir Singh00f0b822008-03-04 14:28:39 -0800941
942 Note that setting this option increases fixed memory overhead
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700943 associated with each page of memory in the system. By this,
Sergey Dyaslyf60e2a92013-07-03 15:03:30 -0700944 8(16)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700945 usage tracking struct at boot. Total amount of this is printed out
946 at boot.
Balbir Singh00f0b822008-03-04 14:28:39 -0800947
948 Only enable when you're ok with these trade offs and really
KAMEZAWA Hiroyuki84ad6d72008-10-29 14:01:06 -0700949 sure you need the memory resource controller. Even when you enable
950 this, you can set "cgroup_disable=memory" at your boot option to
951 disable memory resource controller and you can avoid overheads.
Li Zefanc9d54092009-01-07 18:07:35 -0800952 (and lose benefits of memory resource controller)
Balbir Singh00f0b822008-03-04 14:28:39 -0800953
Balbir Singhcf475ad2008-04-29 01:00:16 -0700954 This config option also selects MM_OWNER config option, which
955 could in turn add some fork/exit overhead.
956
Andrew Mortonc255a452012-07-31 16:43:02 -0700957config MEMCG_SWAP
KAMEZAWA Hiroyuki65e0e812010-08-10 18:02:56 -0700958 bool "Memory Resource Controller Swap Extension"
Andrew Mortonc255a452012-07-31 16:43:02 -0700959 depends on MEMCG && SWAP
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800960 help
961 Add swap management feature to memory resource controller. When you
962 enable this, you can limit mem+swap usage per cgroup. In other words,
963 when you disable this, memory resource controller has no cares to
964 usage of swap...a process can exhaust all of the swap. This extension
965 is useful when you want to avoid exhaustion swap but this itself
966 adds more overheads and consumes memory for remembering information.
967 Especially if you use 32bit system or small memory system, please
968 be careful about enabling this. When memory resource controller
969 is disabled by boot option, this will be automatically disabled and
970 there will be no overhead from this. Even when you set this config=y,
WANG Cong00a66d22011-07-25 17:12:12 -0700971 if boot option "swapaccount=0" is set, swap will not be accounted.
KAMEZAWA Hiroyuki627991a2009-04-02 16:57:47 -0700972 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
973 size is 4096bytes, 512k per 1Gbytes of swap.
Andrew Mortonc255a452012-07-31 16:43:02 -0700974config MEMCG_SWAP_ENABLED
Michal Hockoa42c3902010-11-24 12:57:08 -0800975 bool "Memory Resource Controller Swap Extension enabled by default"
Andrew Mortonc255a452012-07-31 16:43:02 -0700976 depends on MEMCG_SWAP
Michal Hockoa42c3902010-11-24 12:57:08 -0800977 default y
978 help
979 Memory Resource Controller Swap Extension comes with its price in
980 a bigger memory consumption. General purpose distribution kernels
Jim Cromie43d547f2010-12-17 14:32:36 -0700981 which want to enable the feature but keep it disabled by default
Michal Hocko07555ac2013-08-22 16:35:46 -0700982 and let the user enable it by swapaccount=1 boot command line
Michal Hockoa42c3902010-11-24 12:57:08 -0800983 parameter should have this option unselected.
984 For those who want to have the feature enabled by default should
985 select this option (if, for some reason, they need to disable it
WANG Cong00a66d22011-07-25 17:12:12 -0700986 then swapaccount=0 does the trick).
Andrew Mortonc255a452012-07-31 16:43:02 -0700987config MEMCG_KMEM
Kees Cook19c92392012-10-02 11:19:29 -0700988 bool "Memory Resource Controller Kernel Memory accounting"
989 depends on MEMCG
Glauber Costa510fc4e2012-12-18 14:21:47 -0800990 depends on SLUB || SLAB
Glauber Costae5671df2011-12-11 21:47:01 +0000991 help
992 The Kernel Memory extension for Memory Resource Controller can limit
993 the amount of memory used by kernel objects in the system. Those are
994 fundamentally different from the entities handled by the standard
995 Memory Controller, which are page-based, and can be swapped. Users of
996 the kmem extension can use it to guarantee that no group of processes
997 will ever exhaust kernel resources alone.
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -0800998
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700999config CGROUP_HUGETLB
1000 bool "HugeTLB Resource Controller for Control Groups"
Kees Cook19c92392012-10-02 11:19:29 -07001001 depends on RESOURCE_COUNTERS && HUGETLB_PAGE
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -07001002 default n
1003 help
1004 Provides a cgroup Resource Controller for HugeTLB pages.
1005 When you enable this, you can put a per cgroup limit on HugeTLB usage.
1006 The limit is enforced during page fault. Since HugeTLB doesn't
1007 support page reclaim, enforcing the limit at page fault time implies
1008 that, the application will get SIGBUS signal if it tries to access
1009 HugeTLB pages beyond its limit. This requires the application to know
1010 beforehand how much HugeTLB pages it would require for its use. The
1011 control group is tracked in the third page lru pointer. This means
1012 that we cannot use the controller with huge page less than 3 pages.
1013
Stephane Eraniane5d13672011-02-14 11:20:01 +02001014config CGROUP_PERF
1015 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
1016 depends on PERF_EVENTS && CGROUPS
1017 help
1018 This option extends the per-cpu mode to restrict monitoring to
Li Zefan2d0f2522011-03-03 14:26:20 +08001019 threads which belong to the cgroup specified and run on the
Stephane Eraniane5d13672011-02-14 11:20:01 +02001020 designated cpu.
1021
1022 Say N if unsure.
1023
Dhaval Giani7c941432010-01-20 13:26:18 +01001024menuconfig CGROUP_SCHED
1025 bool "Group CPU scheduler"
Dhaval Giani7c941432010-01-20 13:26:18 +01001026 default n
1027 help
1028 This feature lets CPU scheduler recognize task groups and control CPU
1029 bandwidth allocation to such task groups. It uses cgroups to group
1030 tasks.
1031
1032if CGROUP_SCHED
1033config FAIR_GROUP_SCHED
1034 bool "Group scheduling for SCHED_OTHER"
1035 depends on CGROUP_SCHED
1036 default CGROUP_SCHED
1037
Paul Turnerab84d312011-07-21 09:43:28 -07001038config CFS_BANDWIDTH
1039 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
Paul Turnerab84d312011-07-21 09:43:28 -07001040 depends on FAIR_GROUP_SCHED
1041 default n
1042 help
1043 This option allows users to define CPU bandwidth rates (limits) for
1044 tasks running within the fair group scheduler. Groups with no limit
1045 set are considered to be unconstrained and will run with no
1046 restriction.
1047 See tip/Documentation/scheduler/sched-bwc.txt for more information.
1048
Dhaval Giani7c941432010-01-20 13:26:18 +01001049config RT_GROUP_SCHED
1050 bool "Group scheduling for SCHED_RR/FIFO"
Dhaval Giani7c941432010-01-20 13:26:18 +01001051 depends on CGROUP_SCHED
1052 default n
1053 help
1054 This feature lets you explicitly allocate real CPU bandwidth
Li Zefan32bd7eb2010-03-24 13:17:19 +08001055 to task groups. If enabled, it will also make it impossible to
Dhaval Giani7c941432010-01-20 13:26:18 +01001056 schedule realtime tasks for non-root users until you allocate
1057 realtime bandwidth for them.
1058 See Documentation/scheduler/sched-rt-group.txt for more information.
1059
1060endif #CGROUP_SCHED
1061
Vivek Goyalafc24d42010-04-26 19:27:56 +02001062config BLK_CGROUP
Tejun Heo32e380a2012-03-05 13:14:54 -08001063 bool "Block IO controller"
Daniel Lezcano79ae9c22010-10-27 15:34:39 -07001064 depends on BLOCK
Vivek Goyalafc24d42010-04-26 19:27:56 +02001065 default n
1066 ---help---
1067 Generic block IO controller cgroup interface. This is the common
1068 cgroup interface which should be used by various IO controlling
1069 policies.
1070
1071 Currently, CFQ IO scheduler uses it to recognize task groups and
1072 control disk bandwidth allocation (proportional time slice allocation)
Vivek Goyale43473b2010-09-15 17:06:35 -04001073 to such task groups. It is also used by bio throttling logic in
1074 block layer to implement upper limit in IO rates on a device.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001075
1076 This option only enables generic Block IO controller infrastructure.
Vivek Goyale43473b2010-09-15 17:06:35 -04001077 One needs to also enable actual IO controlling logic/policy. For
Michael Witten79e2e752011-01-16 21:43:10 +00001078 enabling proportional weight division of disk bandwidth in CFQ, set
1079 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
Michael Wittenc5e05912011-01-17 00:08:41 +00001080 CONFIG_BLK_DEV_THROTTLING=y.
Vivek Goyalafc24d42010-04-26 19:27:56 +02001081
1082 See Documentation/cgroups/blkio-controller.txt for more information.
1083
1084config DEBUG_BLK_CGROUP
1085 bool "Enable Block IO controller debugging"
1086 depends on BLK_CGROUP
1087 default n
1088 ---help---
1089 Enable some debugging help. Currently it exports additional stat
1090 files in a cgroup which can be useful for debugging.
1091
Li Zefan23964d22009-01-15 13:50:58 -08001092endif # CGROUPS
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001093
Cyrill Gorcunov067bce12012-01-12 17:20:49 -08001094config CHECKPOINT_RESTORE
1095 bool "Checkpoint/restore support" if EXPERT
1096 default n
1097 help
1098 Enables additional kernel features in a sake of checkpoint/restore.
1099 In particular it adds auxiliary prctl codes to setup process text,
1100 data and heap segment sizes, and a few additional /proc filesystem
1101 entries.
1102
1103 If unsure, say N here.
1104
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001105menuconfig NAMESPACES
David Rientjes6a108a12011-01-20 14:44:16 -08001106 bool "Namespaces support" if EXPERT
1107 default !EXPERT
Pavel Emelyanovc5289a62008-02-08 04:18:19 -08001108 help
1109 Provides the way to make tasks work with different objects using
1110 the same id. For example same IPC id may refer to different objects
1111 or same user id or pid may refer to different tasks when used in
1112 different namespaces.
1113
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001114if NAMESPACES
1115
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001116config UTS_NS
1117 bool "UTS namespace"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001118 default y
Pavel Emelyanov58bfdd6d2008-02-08 04:18:21 -08001119 help
1120 In this namespace tasks see different info provided with the
1121 uname() system call
1122
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001123config IPC_NS
1124 bool "IPC namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001125 depends on (SYSVIPC || POSIX_MQUEUE)
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001126 default y
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001127 help
1128 In this namespace tasks work with IPC ids which correspond to
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001129 different IPC objects in different namespaces.
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001130
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001131config USER_NS
Kees Cook19c92392012-10-02 11:19:29 -07001132 bool "User namespace"
Eric W. Biederman5673a942011-11-17 10:23:55 -08001133 default n
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001134 help
1135 This allows containers, i.e. vservers, to use user namespaces
1136 to provide different user info for different servers.
Eric W. Biedermane11f0ae2013-01-25 16:48:31 -08001137
1138 When user namespaces are enabled in the kernel it is
1139 recommended that the MEMCG and MEMCG_KMEM options also be
1140 enabled and that user-space use the memory control groups to
1141 limit the amount of memory a memory unprivileged users can
1142 use.
1143
Pavel Emelyanovaee16ce2008-02-08 04:18:23 -08001144 If unsure, say N.
1145
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001146config PID_NS
Daniel Lezcano9bd38c22010-10-27 15:34:37 -07001147 bool "PID Namespaces"
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001148 default y
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001149 help
Heikki Orsila12d2b8f2008-07-06 15:48:02 +03001150 Support process id namespaces. This allows having multiple
Matt LaPlante692105b2009-01-26 11:12:25 +01001151 processes with the same pid as long as they are in different
Pavel Emelyanov74bd59b2008-02-08 04:18:24 -08001152 pid namespaces. This is a building block of containers.
1153
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001154config NET_NS
1155 bool "Network namespace"
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001156 depends on NET
Daniel Lezcano17a6d442010-10-27 15:34:37 -07001157 default y
Matt Helsleyd6eb6332009-01-26 12:25:55 -08001158 help
1159 Allow user space to create what appear to be multiple instances
1160 of the network stack.
1161
Daniel Lezcano8dd2a822010-10-27 15:34:38 -07001162endif # NAMESPACES
1163
Mike Galbraith5091faa2010-11-30 14:18:03 +01001164config SCHED_AUTOGROUP
1165 bool "Automatic process group scheduling"
Mike Galbraith5091faa2010-11-30 14:18:03 +01001166 select CGROUPS
1167 select CGROUP_SCHED
1168 select FAIR_GROUP_SCHED
1169 help
1170 This option optimizes the scheduler for common desktop workloads by
1171 automatically creating and populating task groups. This separation
1172 of workloads isolates aggressive CPU burners (like build jobs) from
1173 desktop applications. Task group autogeneration is currently based
1174 upon task session.
1175
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001176config MM_OWNER
1177 bool
1178
1179config SYSFS_DEPRECATED
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001180 bool "Enable deprecated sysfs features to support old userspace tools"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001181 depends on SYSFS
1182 default n
1183 help
1184 This option adds code that switches the layout of the "block" class
1185 devices, to not show up in /sys/class/block/, but only in
1186 /sys/block/.
1187
1188 This switch is only active when the sysfs.deprecated=1 boot option is
1189 passed or the SYSFS_DEPRECATED_V2 option is set.
1190
1191 This option allows new kernels to run on old distributions and tools,
1192 which might get confused by /sys/class/block/. Since 2007/2008 all
1193 major distributions and tools handle this just fine.
1194
1195 Recent distributions and userspace tools after 2009/2010 depend on
1196 the existence of /sys/class/block/, and will not work with this
1197 option enabled.
1198
1199 Only if you are using a new kernel on an old distribution, you might
1200 need to say Y here.
1201
1202config SYSFS_DEPRECATED_V2
Ferenc Wagner5d6a4ea2011-01-10 19:04:22 +01001203 bool "Enable deprecated sysfs features by default"
Daniel Lezcano7af37be2010-10-27 15:34:41 -07001204 default n
1205 depends on SYSFS
1206 depends on SYSFS_DEPRECATED
1207 help
1208 Enable deprecated sysfs by default.
1209
1210 See the CONFIG_SYSFS_DEPRECATED option for more details about this
1211 option.
1212
1213 Only if you are using a new kernel on an old distribution, you might
1214 need to say Y here. Even then, odds are you would not need it
1215 enabled, you can always pass the boot option if absolutely necessary.
1216
1217config RELAY
1218 bool "Kernel->user space relay support (formerly relayfs)"
1219 help
1220 This option enables support for relay interface support in
1221 certain file systems (such as debugfs).
1222 It is designed to provide an efficient mechanism for tools and
1223 facilities to relay large amounts of data from kernel space to
1224 user space.
1225
1226 If unsure, say N.
1227
Dimitri Gorokhovikf9916332007-03-06 01:42:17 -08001228config BLK_DEV_INITRD
1229 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
1230 depends on BROKEN || !FRV
1231 help
1232 The initial RAM filesystem is a ramfs which is loaded by the
1233 boot loader (loadlin or lilo) and that is mounted as root
1234 before the normal boot procedure. It is typically used to
1235 load modules needed to mount the "real" root file system,
1236 etc. See <file:Documentation/initrd.txt> for details.
1237
1238 If RAM disk support (BLK_DEV_RAM) is also included, this
1239 also enables initial RAM disk (initrd) support and adds
1240 15 Kbytes (more on some other architectures) to the kernel size.
1241
1242 If unsure say Y.
1243
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001244if BLK_DEV_INITRD
1245
Sam Ravnborgdbec4862005-08-10 20:44:50 +02001246source "usr/Kconfig"
1247
Jean-Paul Samanc33df4e2007-02-10 01:44:43 -08001248endif
1249
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001250config CC_OPTIMIZE_FOR_SIZE
Ingo Molnar96fffeb2008-04-28 01:39:43 +02001251 bool "Optimize for size"
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001252 help
1253 Enabling this option will pass "-Os" instead of "-O2" to gcc
1254 resulting in a smaller kernel.
1255
Kirill Smelkov3a55fb02012-11-02 15:41:01 +04001256 If unsure, say N.
Linus Torvaldsc45b4f12005-12-14 18:52:21 -08001257
Randy Dunlap08470622006-09-30 23:28:13 -07001258config SYSCTL
1259 bool
1260
Randy Dunlapb943c462009-03-10 12:55:46 -07001261config ANON_INODES
1262 bool
1263
Mike Frysinger657a5202013-04-30 15:28:45 -07001264config HAVE_UID16
1265 bool
1266
1267config SYSCTL_EXCEPTION_TRACE
1268 bool
1269 help
1270 Enable support for /proc/sys/debug/exception-trace.
1271
1272config SYSCTL_ARCH_UNALIGN_NO_WARN
1273 bool
1274 help
1275 Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1276 Allows arch to define/use @no_unaligned_warning to possibly warn
1277 about unaligned access emulation going on under the hood.
1278
1279config SYSCTL_ARCH_UNALIGN_ALLOW
1280 bool
1281 help
1282 Enable support for /proc/sys/kernel/unaligned-trap
1283 Allows arches to define/use @unaligned_enabled to runtime toggle
1284 the unaligned access emulation.
1285 see arch/parisc/kernel/unaligned.c for reference
1286
Mike Frysinger657a5202013-04-30 15:28:45 -07001287config HAVE_PCSPKR_PLATFORM
1288 bool
1289
David Rientjes6a108a12011-01-20 14:44:16 -08001290menuconfig EXPERT
1291 bool "Configure standard kernel features (expert users)"
Josh Triplettf505c552011-06-05 18:23:58 -07001292 # Unhide debug options, to make the on-by-default options visible
1293 select DEBUG_KERNEL
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 help
1295 This option allows certain base kernel options and settings
1296 to be disabled or tweaked. This is for specialized
1297 environments which can tolerate a "non-standard" kernel.
1298 Only use this if you really know what you are doing.
1299
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001300config UID16
David Rientjes6a108a12011-01-20 14:44:16 -08001301 bool "Enable 16-bit UID system calls" if EXPERT
Catalin Marinasaf1839e2012-10-08 16:28:08 -07001302 depends on HAVE_UID16
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001303 default y
1304 help
1305 This enables the legacy 16-bit UID syscall wrappers.
1306
Fabian Frederick6af9f7b2014-04-03 14:48:25 -07001307config SYSFS_SYSCALL
1308 bool "Sysfs syscall support" if EXPERT
1309 default y
1310 ---help---
1311 sys_sysfs is an obsolete system call no longer supported in libc.
1312 Note that disabling this option is more secure but might break
1313 compatibility with some systems.
1314
1315 If unsure say Y here.
1316
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001317config SYSCTL_SYSCALL
David Rientjes6a108a12011-01-20 14:44:16 -08001318 bool "Sysctl syscall support" if EXPERT
Eric W. Biederman26a70342009-11-05 05:26:41 -08001319 depends on PROC_SYSCTL
WANG Congc736de62011-11-02 13:39:25 -07001320 default n
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001321 select SYSCTL
1322 ---help---
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001323 sys_sysctl uses binary paths that have been found challenging
1324 to properly maintain and use. The interface in /proc/sys
1325 using paths with ascii names is now the primary path to this
1326 information.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001327
Eric W. Biederman13bb7e32006-11-08 17:44:51 -08001328 Almost nothing using the binary sysctl interface so if you are
1329 trying to save some space it is probably safe to disable this,
1330 making your kernel marginally smaller.
Eric W. Biedermanb89a8172006-09-27 01:51:04 -07001331
WANG Congc736de62011-11-02 13:39:25 -07001332 If unsure say N here.
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001333
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334config KALLSYMS
David Rientjes6a108a12011-01-20 14:44:16 -08001335 bool "Load all symbols for debugging/ksymoops" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 default y
1337 help
1338 Say Y here to let the kernel print out symbolic crash information and
1339 symbolic stack backtraces. This increases the size of the kernel
1340 somewhat, as all symbols have to be loaded into the kernel image.
1341
1342config KALLSYMS_ALL
1343 bool "Include all symbols in kallsyms"
1344 depends on DEBUG_KERNEL && KALLSYMS
1345 help
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001346 Normally kallsyms only contains the symbols of functions for nicer
1347 OOPS messages and backtraces (i.e., symbols from the text and inittext
1348 sections). This is sufficient for most cases. And only in very rare
1349 cases (e.g., when a debugger is used) all symbols are required (e.g.,
1350 names of variables from the data sections, etc).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001352 This option makes sure that all symbols are loaded into the kernel
1353 image (i.e., symbols from all sections) in cost of increased kernel
1354 size (depending on the kernel configuration, it may be 300KiB or
1355 something like this).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356
Artem Bityutskiy71a83ec2011-04-05 13:24:57 +03001357 Say N unless you really need all symbols.
Matt Mackalld59745c2005-05-01 08:59:02 -07001358
1359config PRINTK
1360 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001361 bool "Enable support for printk" if EXPERT
Frederic Weisbecker74876a92012-10-12 18:00:23 +02001362 select IRQ_WORK
Matt Mackalld59745c2005-05-01 08:59:02 -07001363 help
1364 This option enables normal printk support. Removing it
1365 eliminates most of the message strings from the kernel image
1366 and makes the kernel more or less silent. As this makes it
1367 very difficult to diagnose system problems, saying N here is
1368 strongly discouraged.
1369
Matt Mackallc8538a72005-05-01 08:59:01 -07001370config BUG
David Rientjes6a108a12011-01-20 14:44:16 -08001371 bool "BUG() support" if EXPERT
Matt Mackallc8538a72005-05-01 08:59:01 -07001372 default y
1373 help
1374 Disabling this option eliminates support for BUG and WARN, reducing
1375 the size of your kernel image and potentially quietly ignoring
1376 numerous fatal conditions. You should only consider disabling this
1377 option for embedded systems with no facilities for reporting errors.
1378 Just say Y.
1379
Matt Mackall708e9a72006-01-08 01:05:25 -08001380config ELF_CORE
Alex Kelly046d6622012-10-04 17:15:23 -07001381 depends on COREDUMP
Matt Mackall708e9a72006-01-08 01:05:25 -08001382 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001383 bool "Enable ELF core dumps" if EXPERT
Matt Mackall708e9a72006-01-08 01:05:25 -08001384 help
1385 Enable support for generating core dumps. Disabling saves about 4k.
1386
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001387
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001388config PCSPKR_PLATFORM
David Rientjes6a108a12011-01-20 14:44:16 -08001389 bool "Enable PC-Speaker support" if EXPERT
Ralf Baechle8761f1a2011-06-01 19:05:09 +01001390 depends on HAVE_PCSPKR_PLATFORM
Ralf Baechle15f304b2011-06-01 19:04:59 +01001391 select I8253_LOCK
Stas Sergeeve5e1d3c2008-05-07 12:39:56 +02001392 default y
1393 help
1394 This option allows to disable the internal PC-Speaker
1395 support, saving some memory.
1396
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397config BASE_FULL
1398 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001399 bool "Enable full-sized data structures for core" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 help
1401 Disabling this option reduces the size of miscellaneous core
1402 kernel data structures. This saves memory on small machines,
1403 but may reduce performance.
1404
1405config FUTEX
David Rientjes6a108a12011-01-20 14:44:16 -08001406 bool "Enable futex support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 default y
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001408 select RT_MUTEXES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 help
1410 Disabling this option will cause the kernel to be built without
1411 support for "fast userspace mutexes". The resulting kernel may not
1412 run glibc-based applications correctly.
1413
Heiko Carstens03b8c7b2014-03-02 13:09:47 +01001414config HAVE_FUTEX_CMPXCHG
1415 bool
1416 help
1417 Architectures should select this if futex_atomic_cmpxchg_inatomic()
1418 is implemented and always working. This removes a couple of runtime
1419 checks.
1420
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421config EPOLL
David Rientjes6a108a12011-01-20 14:44:16 -08001422 bool "Enable eventpoll support" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 default y
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001424 select ANON_INODES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 help
1426 Disabling this option will cause the kernel to be built without
1427 support for epoll family of system calls.
1428
Davide Libenzifba2afa2007-05-10 22:23:13 -07001429config SIGNALFD
David Rientjes6a108a12011-01-20 14:44:16 -08001430 bool "Enable signalfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001431 select ANON_INODES
Davide Libenzifba2afa2007-05-10 22:23:13 -07001432 default y
1433 help
1434 Enable the signalfd() system call that allows to receive signals
1435 on a file descriptor.
1436
1437 If unsure, say Y.
1438
Davide Libenzib215e282007-05-10 22:23:16 -07001439config TIMERFD
David Rientjes6a108a12011-01-20 14:44:16 -08001440 bool "Enable timerfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001441 select ANON_INODES
Davide Libenzib215e282007-05-10 22:23:16 -07001442 default y
1443 help
1444 Enable the timerfd() system call that allows to receive timer
1445 events on a file descriptor.
1446
1447 If unsure, say Y.
1448
Davide Libenzie1ad7462007-05-10 22:23:19 -07001449config EVENTFD
David Rientjes6a108a12011-01-20 14:44:16 -08001450 bool "Enable eventfd() system call" if EXPERT
Adrian Bunk448e3ce2007-07-31 00:39:10 -07001451 select ANON_INODES
Davide Libenzie1ad7462007-05-10 22:23:19 -07001452 default y
1453 help
1454 Enable the eventfd() system call that allows to receive both
1455 kernel notification (ie. KAIO) or userspace notifications.
1456
1457 If unsure, say Y.
1458
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459config SHMEM
David Rientjes6a108a12011-01-20 14:44:16 -08001460 bool "Use full shmem filesystem" if EXPERT
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 default y
1462 depends on MMU
1463 help
1464 The shmem is an internal filesystem used to manage shared memory.
1465 It is backed by swap and manages resource limits. It is also exported
1466 to userspace as tmpfs if TMPFS is enabled. Disabling this
1467 option replaces shmem and tmpfs with the much simpler ramfs code,
1468 which may be appropriate on small systems without swap.
1469
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001470config AIO
David Rientjes6a108a12011-01-20 14:44:16 -08001471 bool "Enable AIO support" if EXPERT
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001472 default y
1473 help
1474 This option enables POSIX asynchronous I/O which may by used
Mike Frysinger657a5202013-04-30 15:28:45 -07001475 by some high performance threaded applications. Disabling
1476 this option saves about 7k.
1477
1478config PCI_QUIRKS
1479 default y
1480 bool "Enable PCI quirk workarounds" if EXPERT
1481 depends on PCI
1482 help
1483 This enables workarounds for various PCI chipset
1484 bugs/quirks. Disable this only if your target machine is
1485 unaffected by PCI quirks.
Thomas Petazzoniebf3f092008-10-15 22:05:12 -07001486
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001487config EMBEDDED
1488 bool "Embedded system"
Josh Triplett5d2acfc2014-04-07 15:39:09 -07001489 option allnoconfig_y
Randy Dunlap6befe5f2011-04-26 12:33:21 -07001490 select EXPERT
1491 help
1492 This option should be enabled if compiling the kernel for
1493 an embedded system so certain expert options are available
1494 for configuration.
1495
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001496config HAVE_PERF_EVENTS
Thomas Gleixner0793a612008-12-04 20:12:29 +01001497 bool
Mike Frysinger018df722009-06-12 13:17:43 -04001498 help
1499 See tools/perf/design.txt for details.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001500
Peter Zijlstra906010b2009-09-21 16:08:49 +02001501config PERF_USE_VMALLOC
1502 bool
1503 help
1504 See tools/perf/design.txt for details
1505
Ingo Molnar57c0c152009-09-21 12:20:38 +02001506menu "Kernel Performance Events And Counters"
Thomas Gleixner0793a612008-12-04 20:12:29 +01001507
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001508config PERF_EVENTS
Ingo Molnar57c0c152009-09-21 12:20:38 +02001509 bool "Kernel performance events and counters"
Robert Richter392d65a2012-04-05 18:24:44 +02001510 default y if PROFILING
Ingo Molnarcdd6c482009-09-21 12:02:48 +02001511 depends on HAVE_PERF_EVENTS
Ingo Molnar4c59e462008-12-08 19:38:33 +01001512 select ANON_INODES
Peter Zijlstrae360adb2010-10-14 14:01:34 +08001513 select IRQ_WORK
Thomas Gleixner0793a612008-12-04 20:12:29 +01001514 help
Ingo Molnar57c0c152009-09-21 12:20:38 +02001515 Enable kernel support for various performance events provided
1516 by software and hardware.
Thomas Gleixner0793a612008-12-04 20:12:29 +01001517
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001518 Software events are supported either built-in or via the
Ingo Molnar57c0c152009-09-21 12:20:38 +02001519 use of generic tracepoints.
1520
1521 Most modern CPUs support performance events via performance
1522 counter registers. These registers count the number of certain
Thomas Gleixner0793a612008-12-04 20:12:29 +01001523 types of hw events: such as instructions executed, cachemisses
1524 suffered, or branches mis-predicted - without slowing down the
1525 kernel or applications. These registers can also trigger interrupts
1526 when a threshold number of events have passed - and can thus be
1527 used to profile the code that runs on that CPU.
1528
Ingo Molnar57c0c152009-09-21 12:20:38 +02001529 The Linux Performance Event subsystem provides an abstraction of
Thadeu Lima de Souza Cascardodd770382009-10-30 19:32:25 -02001530 these software and hardware event capabilities, available via a
Ingo Molnar57c0c152009-09-21 12:20:38 +02001531 system call and used by the "perf" utility in tools/perf/. It
Thomas Gleixner0793a612008-12-04 20:12:29 +01001532 provides per task and per CPU counters, and it provides event
1533 capabilities on top of those.
1534
1535 Say Y if unsure.
1536
Peter Zijlstra906010b2009-09-21 16:08:49 +02001537config DEBUG_PERF_USE_VMALLOC
1538 default n
1539 bool "Debug: use vmalloc to back perf mmap() buffers"
1540 depends on PERF_EVENTS && DEBUG_KERNEL
1541 select PERF_USE_VMALLOC
1542 help
1543 Use vmalloc memory to back perf mmap() buffers.
1544
1545 Mostly useful for debugging the vmalloc code on platforms
1546 that don't require it.
1547
1548 Say N if unsure.
1549
Thomas Gleixner0793a612008-12-04 20:12:29 +01001550endmenu
1551
Christoph Lameterf8891e52006-06-30 01:55:45 -07001552config VM_EVENT_COUNTERS
1553 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001554 bool "Enable VM event counters for /proc/vmstat" if EXPERT
Christoph Lameterf8891e52006-06-30 01:55:45 -07001555 help
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001556 VM event counters are needed for event counts to be shown.
1557 This option allows the disabling of the VM event counters
David Rientjes6a108a12011-01-20 14:44:16 -08001558 on EXPERT systems. /proc/vmstat will only show page counts
Paul Jackson2aea4fb2006-12-22 01:06:10 -08001559 if VM event counters are disabled.
Christoph Lameterf8891e52006-06-30 01:55:45 -07001560
Christoph Lameter41ecc552007-05-09 02:32:44 -07001561config SLUB_DEBUG
1562 default y
David Rientjes6a108a12011-01-20 14:44:16 -08001563 bool "Enable SLUB debugging support" if EXPERT
Christoph Lameterf6acb632008-04-29 16:16:06 -07001564 depends on SLUB && SYSFS
Christoph Lameter41ecc552007-05-09 02:32:44 -07001565 help
1566 SLUB has extensive debug support features. Disabling these can
1567 result in significant savings in code size. This also disables
1568 SLUB sysfs support. /sys/slab will not exist and there will be
1569 no support for cache validation etc.
1570
Randy Dunlapb943c462009-03-10 12:55:46 -07001571config COMPAT_BRK
1572 bool "Disable heap randomization"
1573 default y
1574 help
1575 Randomizing heap placement makes heap exploits harder, but it
1576 also breaks ancient binaries (including anything libc5 based).
1577 This option changes the bootup default to heap randomization
Matt LaPlante692105b2009-01-26 11:12:25 +01001578 disabled, and can be overridden at runtime by setting
Randy Dunlapb943c462009-03-10 12:55:46 -07001579 /proc/sys/kernel/randomize_va_space to 2.
1580
1581 On non-ancient distros (post-2000 ones) N is usually a safe choice.
1582
Christoph Lameter81819f02007-05-06 14:49:36 -07001583choice
1584 prompt "Choose SLAB allocator"
Christoph Lametera0acd822007-07-17 04:03:32 -07001585 default SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001586 help
1587 This option allows to select a slab allocator.
1588
1589config SLAB
1590 bool "SLAB"
1591 help
1592 The regular slab allocator that is established and known to work
Christoph Lameter34013882007-05-09 02:32:47 -07001593 well in all environments. It organizes cache hot objects in
Simon Arlott02f56212008-11-05 22:18:19 +00001594 per cpu and per node queues.
Christoph Lameter81819f02007-05-06 14:49:36 -07001595
1596config SLUB
Christoph Lameter81819f02007-05-06 14:49:36 -07001597 bool "SLUB (Unqueued Allocator)"
1598 help
1599 SLUB is a slab allocator that minimizes cache line usage
1600 instead of managing queues of cached objects (SLAB approach).
1601 Per cpu caching is realized using slabs of objects instead
1602 of queues of objects. SLUB can use memory efficiently
Simon Arlott02f56212008-11-05 22:18:19 +00001603 and has enhanced diagnostics. SLUB is the default choice for
1604 a slab allocator.
Christoph Lameter81819f02007-05-06 14:49:36 -07001605
1606config SLOB
David Rientjes6a108a12011-01-20 14:44:16 -08001607 depends on EXPERT
Christoph Lameter81819f02007-05-06 14:49:36 -07001608 bool "SLOB (Simple Allocator)"
1609 help
Matt Mackall37291452008-02-04 22:29:38 -08001610 SLOB replaces the stock allocator with a drastically simpler
1611 allocator. SLOB is generally more space efficient but
1612 does not perform as well on large systems.
Christoph Lameter81819f02007-05-06 14:49:36 -07001613
1614endchoice
1615
Joonsoo Kim345c9052013-06-19 14:05:52 +09001616config SLUB_CPU_PARTIAL
1617 default y
Uwe Kleine-Königb39ffbf2013-07-17 16:54:59 +02001618 depends on SLUB && SMP
Joonsoo Kim345c9052013-06-19 14:05:52 +09001619 bool "SLUB per cpu partial cache"
1620 help
1621 Per cpu partial caches accellerate objects allocation and freeing
1622 that is local to a processor at the price of more indeterminism
1623 in the latency of the free. On overflow these caches will be cleared
1624 which requires the taking of locks that may cause latency spikes.
1625 Typically one would choose no for a realtime system.
1626
Jie Zhangea637632009-12-14 18:00:02 -08001627config MMAP_ALLOW_UNINITIALIZED
1628 bool "Allow mmapped anonymous memory to be uninitialized"
David Rientjes6a108a12011-01-20 14:44:16 -08001629 depends on EXPERT && !MMU
Jie Zhangea637632009-12-14 18:00:02 -08001630 default n
1631 help
1632 Normally, and according to the Linux spec, anonymous memory obtained
1633 from mmap() has it's contents cleared before it is passed to
1634 userspace. Enabling this config option allows you to request that
1635 mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
1636 providing a huge performance boost. If this option is not enabled,
1637 then the flag will be ignored.
1638
1639 This is taken advantage of by uClibc's malloc(), and also by
1640 ELF-FDPIC binfmt's brk and stack allocator.
1641
1642 Because of the obvious security issues, this option should only be
1643 enabled on embedded devices where you control what is run in
1644 userspace. Since that isn't generally a problem on no-MMU systems,
1645 it is normally safe to say Y here.
1646
1647 See Documentation/nommu-mmap.txt for more information.
1648
Peter Foley82c04ff2014-04-18 15:07:11 -07001649config SYSTEM_TRUSTED_KEYRING
1650 bool "Provide system-wide ring of trusted keys"
1651 depends on KEYS
1652 help
1653 Provide a system keyring to which trusted keys can be added. Keys in
1654 the keyring are considered to be trusted. Keys may be added at will
1655 by the kernel from compiled-in data and from hardware key stores, but
1656 userspace may only add extra keys if those keys can be verified by
1657 keys already in the keyring.
1658
1659 Keys in this keyring are used by module signature checking.
1660
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001661config PROFILING
Robert Richterb309a292010-02-26 15:01:23 +01001662 bool "Profiling support"
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05001663 help
1664 Say Y here to enable the extended profiling support mechanisms used
1665 by profilers such as OProfile.
1666
Ingo Molnar5f87f112008-07-23 14:15:22 +02001667#
1668# Place an empty function call at each tracepoint site. Can be
1669# dynamically changed for a probe function.
1670#
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001671config TRACEPOINTS
Ingo Molnar5f87f112008-07-23 14:15:22 +02001672 bool
Mathieu Desnoyers97e1c182008-07-18 12:16:16 -04001673
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05001674source "arch/Kconfig"
1675
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676endmenu # General setup
1677
Dmitry Baryshkovee7e5512008-06-29 14:18:46 +04001678config HAVE_GENERIC_DMA_COHERENT
1679 bool
1680 default n
1681
Linus Torvalds158a9622008-01-02 13:04:48 -08001682config SLABINFO
1683 bool
1684 depends on PROC_FS
Christoph Lameter0f389ec2008-04-14 18:53:02 +03001685 depends on SLAB || SLUB_DEBUG
Linus Torvalds158a9622008-01-02 13:04:48 -08001686 default y
1687
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001688config RT_MUTEXES
1689 boolean
Chuck Ebbertae81f9e2006-09-16 12:15:53 -07001690
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691config BASE_SMALL
1692 int
1693 default 0 if BASE_FULL
1694 default 1 if !BASE_FULL
1695
Jan Engelhardt66da5732007-07-15 23:39:29 -07001696menuconfig MODULES
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 bool "Enable loadable module support"
Yann E. MORIN11097a02013-08-11 16:07:50 +02001698 option modules
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 help
1700 Kernel modules are small pieces of compiled code which can
1701 be inserted in the running kernel, rather than being
1702 permanently built into the kernel. You use the "modprobe"
1703 tool to add (and sometimes remove) them. If you say Y here,
1704 many parts of the kernel can be built as modules (by
1705 answering M instead of Y where indicated): this is most
1706 useful for infrequently used options which are not required
1707 for booting. For more information, see the man pages for
1708 modprobe, lsmod, modinfo, insmod and rmmod.
1709
1710 If you say Y here, you will need to run "make
1711 modules_install" to put the modules under /lib/modules/
1712 where modprobe can find them (you may need to be root to do
1713 this).
1714
1715 If unsure, say Y.
1716
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001717if MODULES
1718
Linus Torvalds826e4502008-05-04 17:04:16 -07001719config MODULE_FORCE_LOAD
1720 bool "Forced module loading"
Linus Torvalds826e4502008-05-04 17:04:16 -07001721 default n
1722 help
Rusty Russell91e37a72008-05-09 16:25:28 +10001723 Allow loading of modules without version information (ie. modprobe
1724 --force). Forced module loading sets the 'F' (forced) taint flag and
1725 is usually a really bad idea.
Linus Torvalds826e4502008-05-04 17:04:16 -07001726
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727config MODULE_UNLOAD
1728 bool "Module unloading"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 help
1730 Without this option you will not be able to unload any
1731 modules (note that some modules may not be unloadable
Denys Vlasenkof7f5b672008-07-22 19:24:26 -05001732 anyway), which makes your kernel smaller, faster
1733 and simpler. If unsure, say Y.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734
1735config MODULE_FORCE_UNLOAD
1736 bool "Forced module unloading"
Kees Cook19c92392012-10-02 11:19:29 -07001737 depends on MODULE_UNLOAD
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 help
1739 This option allows you to force a module to unload, even if the
1740 kernel believes it is unsafe: the kernel will remove the module
1741 without waiting for anyone to stop using it (using the -f option to
1742 rmmod). This is mainly for kernel developers and desperate users.
1743 If unsure, say N.
1744
Linus Torvalds1da177e2005-04-16 15:20:36 -07001745config MODVERSIONS
Sam Ravnborg0d541642005-12-26 23:04:02 +01001746 bool "Module versioning support"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 help
1748 Usually, you have to use modules compiled with your kernel.
1749 Saying Y here makes it sometimes possible to use modules
1750 compiled for different kernels, by adding enough information
1751 to the modules to (hopefully) spot any changes which would
1752 make them incompatible with the kernel you are running. If
1753 unsure, say N.
1754
1755config MODULE_SRCVERSION_ALL
1756 bool "Source checksum for all modules"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 help
1758 Modules which contain a MODULE_VERSION get an extra "srcversion"
1759 field inserted into their modinfo section, which contains a
1760 sum of the source files which made it. This helps maintainers
1761 see exactly which source was used to build a module (since
1762 others sometimes change the module source without updating
1763 the version). With this option, such a "srcversion" field
1764 will be created for all modules. If unsure, say N.
1765
Rusty Russell106a4ee2012-09-26 10:09:40 +01001766config MODULE_SIG
1767 bool "Module signature verification"
1768 depends on MODULES
David Howellsb56e5a12013-08-30 16:07:30 +01001769 select SYSTEM_TRUSTED_KEYRING
David Howells48ba2462012-09-26 10:11:03 +01001770 select KEYS
1771 select CRYPTO
1772 select ASYMMETRIC_KEY_TYPE
1773 select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
1774 select PUBLIC_KEY_ALGO_RSA
1775 select ASN1
1776 select OID_REGISTRY
1777 select X509_CERTIFICATE_PARSER
Rusty Russell106a4ee2012-09-26 10:09:40 +01001778 help
1779 Check modules for valid signatures upon load: the signature
1780 is simply appended to the module. For more information see
1781 Documentation/module-signing.txt.
1782
David Howellsea0b6dc2012-09-26 10:09:50 +01001783 !!!WARNING!!! If you enable this option, you MUST make sure that the
1784 module DOES NOT get stripped after being signed. This includes the
1785 debuginfo strip done by some packagers (such as rpmbuild) and
1786 inclusion into an initramfs that wants the module size reduced.
1787
Rusty Russell106a4ee2012-09-26 10:09:40 +01001788config MODULE_SIG_FORCE
1789 bool "Require modules to be validly signed"
1790 depends on MODULE_SIG
1791 help
1792 Reject unsigned modules or signed modules for which we don't have a
1793 key. Without this, such modules will simply taint the kernel.
David Howellsea0b6dc2012-09-26 10:09:50 +01001794
Michal Marekd9d8d7e2013-01-25 13:41:31 +10301795config MODULE_SIG_ALL
1796 bool "Automatically sign all modules"
1797 default y
1798 depends on MODULE_SIG
1799 help
1800 Sign all modules during make modules_install. Without this option,
1801 modules must be signed manually, using the scripts/sign-file tool.
1802
1803comment "Do not forget to sign required modules with scripts/sign-file"
1804 depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
1805
David Howellsea0b6dc2012-09-26 10:09:50 +01001806choice
1807 prompt "Which hash algorithm should modules be signed with?"
1808 depends on MODULE_SIG
1809 help
1810 This determines which sort of hashing algorithm will be used during
1811 signature generation. This algorithm _must_ be built into the kernel
1812 directly so that signature verification can take place. It is not
1813 possible to load a signed module containing the algorithm to check
1814 the signature on that module.
1815
1816config MODULE_SIG_SHA1
1817 bool "Sign modules with SHA-1"
1818 select CRYPTO_SHA1
1819
1820config MODULE_SIG_SHA224
1821 bool "Sign modules with SHA-224"
1822 select CRYPTO_SHA256
1823
1824config MODULE_SIG_SHA256
1825 bool "Sign modules with SHA-256"
1826 select CRYPTO_SHA256
1827
1828config MODULE_SIG_SHA384
1829 bool "Sign modules with SHA-384"
1830 select CRYPTO_SHA512
1831
1832config MODULE_SIG_SHA512
1833 bool "Sign modules with SHA-512"
1834 select CRYPTO_SHA512
1835
1836endchoice
1837
Michal Marek22753672013-01-25 13:41:00 +10301838config MODULE_SIG_HASH
1839 string
1840 depends on MODULE_SIG
1841 default "sha1" if MODULE_SIG_SHA1
1842 default "sha224" if MODULE_SIG_SHA224
1843 default "sha256" if MODULE_SIG_SHA256
1844 default "sha384" if MODULE_SIG_SHA384
1845 default "sha512" if MODULE_SIG_SHA512
1846
Robert P. J. Day0b0de142008-08-04 13:31:32 -04001847endif # MODULES
1848
Rusty Russell98a79d62008-12-13 21:19:41 +10301849config INIT_ALL_POSSIBLE
1850 bool
1851 help
Rusty Russell5f054e32012-03-29 15:38:31 +10301852 Back when each arch used to define their own cpu_online_mask and
1853 cpu_possible_mask, some of them chose to initialize cpu_possible_mask
Rusty Russell98a79d62008-12-13 21:19:41 +10301854 with all 1s, and others with all 0s. When they were centralised,
1855 it was better to provide this option than to break all the archs
Matt LaPlante692105b2009-01-26 11:12:25 +01001856 and have several arch maintainers pursuing me down dark alleys.
Rusty Russell98a79d62008-12-13 21:19:41 +10301857
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858config STOP_MACHINE
1859 bool
1860 default y
1861 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
1862 help
1863 Need stop_machine() primitive.
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001864
Jens Axboe3a65dfe2005-11-04 08:43:35 +01001865source "block/Kconfig"
Avi Kivitye98c3202007-10-16 23:27:31 -07001866
1867config PREEMPT_NOTIFIERS
1868 bool
Paul E. McKenneye260be62008-01-25 21:08:24 +01001869
Steffen Klassert16295be2010-01-06 19:47:10 +11001870config PADATA
1871 depends on SMP
1872 bool
1873
Andi Kleen754b7b62012-10-04 17:11:27 -07001874# Can be selected by architectures with broken toolchains
1875# that get confused by correct const<->read_only section
1876# mappings
1877config BROKEN_RODATA
1878 bool
1879
David Howells4520c6a2012-09-21 23:31:13 +01001880config ASN1
1881 tristate
1882 help
1883 Build a simple ASN.1 grammar compiler that produces a bytecode output
1884 that can be interpreted by the ASN.1 stream decoder and used to
1885 inform it as to what tags are to be expected in a stream and what
1886 functions to call on what tags.
1887
Thomas Gleixner6beb0002009-11-09 15:21:34 +00001888source "kernel/Kconfig.locks"